Climate Change Effects on Natural Resources FOR 797, Fall 2007 John Stella, [email protected] This seminar examined the evidence of global climate change, integrating scientific analyses and their perceptions in the media. Weekly class discussions focused on different physical, biological, Projected number of snow-covered days (Image: Union of Concerned Scientists) and social facets of the climate change story. Readings were drawn from primary climate change research (Nature, Science), global and regional analyses (IPCC 4th Assessment Report, New England Regional Assessment), news accounts, and the popular science literature (e.g. Tim Flannery’s The Weather Makers).

For the final ‘White Paper’, students summarized the state of knowledge about a particular area, the perception of the issue in the media and popular literature, and the implications for policymakers. (Image: IPCC 2007)

Muir Glacier, Alaska, 1941 and 2004 (Images: William Field, Bruce Molnia, USGS) FOR 797 Climate Change Effects on Natural Resources, Fall 2007 Final White Papers

Table of Contents

Chapter Subject Area Author Page

1 Overview: the physical science basis Katherina Searing 3

2 Paleoclimate and physical changes to the Matt Distler 10 atmosphere 3 Changes to the oceans Kacie Gehl 15

4 Changes to the cryosphere (snow, ice and frozen Brandon Murphy 19 ground) 5 Global and regional climate models Anna Lumsden 26

6 Impacts to freshwater resources Nidhi Pasi 31

7 Carbon sinks and sequestration Ken Hubbard 34

8 Impacts to coastal regions Juliette Smith 38

9 Effects on biodiversity and species ranges Lisa Giencke 43

10 Effects on species’ phenology Laura Heath 47

11 Human health, crop yields and food production Judy Crawford 52

12 Media perceptions of climate change: the Northeast Kristin Cleveland 57 case study 13 Mitigation measures Tony Eallonardo 62

INTRODUCTION Overview: the physical science Climate change is an extremely basis and expected impacts complex issue. Due to this complexity, policymakers required an objective and Katherina Searing comprehensive source of information regarding this topic. The Intergovernmental Panel on EXECUTIVE SUMMARY Climate Change (IPCC) was established by the The fourth assessment report (AR4) of World Meteorological Organization (WMO) and the Intergovernmental Panel on Climate Change the United Nations Environmental Programme (IPCC) is the most comprehensive report of (UNEP) in 1988. The stated goal of the IPCC is climate change science to date. This report states to assess the scientific, technical and socio- that there is clear evidence that global economic information pertaining to the temperatures have increased 0.74°C and sea understanding of the risks associated with levels have increased 17 cm in the 20th century. anthropogenic climate change, its potential By the end of the 21st century, global impacts and the mitigation strategies available. temperatures are predicted to increase between This international organization does not conduct 1.8 to 4.0°C and sea levels are expected to rise research nor does it collect climate related data. between 18 and 59 cm. Most importantly, this They rely on peer reviewed scientific and latest synthesis of climate change science reports, technical literature that has been published. The with 90% confidence, that human activities have IPCC also does not prescribe policy. caused a warming of the planet. The IPCC published their fourth This new report also highlights some of the assessment report (AR4) in 2007. Contributions likely impacts of increased temperatures and sea to this report were made by 1250 lead and level rise on six different sectors: freshwater contributing authors from more than 130 resources and their management; ecosystems, countries and the report was reviewed by more their properties, goods and services; food, fiber than 2500 scientific experts.1 This latest report and forest products; coastal systems and low includes several advancements over the previous lying areas; industry, settlement and society; and reports (most recently the third assessment report human health. Additionally, some regions of the [TAR] in 2001)2, such as tighter estimates and a world are identified as more vulnerable to the better understanding of uncertainties provided by effects of climate change, based on their substantial new data collection and research. 3 geographical location and adaptation capacity. The IPCC is currently divided it to three working The media plays an important role in the groups. Working Group I (WG I) reports on climate change arena by bringing the issue to “The Physical Basis of Climate Change,” people’s attention and by helping to shape public Working Group II (WG II) focuses on “Climate opinion. The release of the components of the Change: Impacts, Adaptation and Vulnerability,” AR4 earlier in 2007 and the publication of final and Working Group III deals with the version in November 2007, received a great deal “Mitigation of Climate Change.” The findings of media attention. of WGs I and II will be discussed here. Some scientists have expressed concerns about the findings of the IPCC due to the exclusion of some recent scientific data pertaining to the melting of glaciers and the ice sheets. The IPCC has been criticized for not 1 Chairman Pauchuri, Chairman of the IPCC Presentation: communicating these limitations clearly in the “IPCC Fourth Assessment Report: Synthesis Report” highly influential “Summary for Policymakers” Valencia, Spain. November 17, 2007. 2 documents that are utilized by decision makers. IPCC, 2001: Summary for Policymakers. In: Climate Aside from what is included in the AR4, Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the policymakers should consider the following Intergovernmental Panel on Climate Change [Houghton, when constructing policies concerning climate J.T.,Y. Ding, D.J. Griggs, M. Noguer, P.J. van der Linden, X. change: the spatial and temporal scale of climate Dai, K. Maskell, and C.A. Johnson (eds.)]. Cambridge change and its impacts, the economics of the University Press, Cambridge, United Kingdom and New prospective policies, and the security issues York, NY, USA. 3 regarding the effects of climate change. Chairman Pauchuri, Chairman of the IPCC Presentation: “Introduction to AR4” Bonn, Germany. May 12, 2007. SEARING OVERVIEW FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

STATE OF THE SCIENCE especially CO2 and CH4. A number of models have been constructed to predict how surface Working Group I: The Physical Science temperatures would change with a continued Basis increase in greenhouse gases. These models Perhaps the most important statement in project increases of about 0.2°C are over the next the recent report of WG I is that “warming of the two decades for a range of greenhouse gas climate system is unequivocal.” 4 , This emission scenarios. Projections for the year declaration is based on direct observations of 2100 range from increases of 1.8 to 4.0°C, increased global air and ocean temperatures, depending upon the concentration of greenhouse rising global sea level and reductions in snow gases released into the atmosphere. Sea level is and ice in the Northern hemisphere. The 100- projected to increase by 18 to 59 cm by the end year trend of increasing global average air of the 21st century. 6 The upper sea level temperature was approximately 0.74°C, up from projection has decreased since the TAR from 88 0.60°C, given in the TAR. This report also cm to 59 cm. Even if the greenhouse gas stated that the average ocean temperatures have concentrations could be stabilized, further increase to depths up to 3000 m. This heating warming and sea level rise would continue for leads to seawater expansion and consequently centuries due to the effects of the greenhouse sea level rise. Global average sea level rose on gases already present in the atmosphere. average 1.8 mm per year from 1861 to 2003 and there is some evidence that the rates of sea level Working Group II: Impacts, Adaptation rise are increasing.5 Sea levels increased a total and Vulnerability th of 17 cm during the 20 century. Reasons for the The major findings of WG II in the AR47, increased sea level include the melting of the are that the impacts of climate change are glaciers, ice caps and polar ice sheets. already occurring and they are now detectable at 8 Warming trends have not been uniform a global scale. Potential impacts of climate across the globe. Temperatures in the Arctic change were identified in six sectors: have increased at almost twice the global average 1) Freshwater resources and their management rate over the past century and the sea ice extent in the Arctic has shrunk by 2.7% per decade. „ Changes in average river runoff and The last time the Polar Regions were warmer water availability than at present, for an extended period of time „ Drought affected areas will expand (125,000 years ago), the melting of polar ice led to 4 to 6 m of sea level rise. Information gained „ Increased frequency of heavy from examining the paleoclimatic record informs precipitation events us that the warming that has occurred in the past „ Increased flood risk 50 years is unusual in the past 1,300 years. 2) Ecosystems, their properties, goods and This observed warming is due to both services natural and anthropogenic forces. Only climate models that incorporate both natural and „ Net carbon uptake will peak prior to anthropogenic factors can explain the changes in 2050 and then weaken or reverse surface temperatures over the past 100 years. Foremost among these anthropogenic factors is the increased concentration of greenhouses gases,

6 The predicted sea level rise is for the years 2090-2099 4 IPCC, 2007: Summary for Policymakers. In: Climate relative to 1980-1999. Ibid. p 13. Change 2007: The Physical Science Basis. Contribution of 7 IPCC, 2007: Summary for Policymakers. In: Climate Working Group I to the Fourth Assessment Report of the Change 2007: Impacts, Adaptation and Vulnerability. Intergovernmental Panel on Climate Change [Solomon, S., D. Contribution of Working Group II to the Fourth Assessment Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, Report of the Intergovernmental Panel on Climate Change, M.Tignor and H.L. Miller (eds.)]. Cambridge University M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden Press, Cambridge, United Kingdom and New York, NY, and C.E. Hanson, Eds., Cambridge University Press, USA. Cambridge, UK. 5 The rate of sea level rise was higher between 1993 and 2003, 8 In the third assessment report (2001), only impacts at the with the sea level increasing by 3.1 mm per year. However it regional scale could be detected. Presentation of WGII 2007: is not known whether this reflects a true increase or if it is “Climate Change 2007: Impacts, Adaptation and simply decadal variation. Ibid. pp 5-7. Vulnerability” Brussels. April 6, 2007.

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„ Around 20 – 30% of animal and plant species are likely to be at an increased Given these potential impacts, it is possible risk of extinction to identify regions of world that are the most vulnerable. The regions in the world that are „ Major changes in ecosystem structure most at risk are the Arctic, Africa (particularly and function Sub-Saharan Africa), small islands and the Asian „ Coral reefs and marine shelled mega-deltas. Some adaptation to the effects of organisms are particularly vulnerable climate change is occurring now but more will be required in order to contend with the future 3) Food, fiber and forest products impacts of climate change. These responses may „ Crop productivity will increase include a variety of adaptation mechanisms, such slightly at mid- to high latitudes for as technological, behavioral, managerial and temperature increases of 1-3°C policy changes. increases and will decrease beyond that PERSPECTIVES IN THE MEDIA AND PUBLIC POLICY „ Crop productivity at low latitudes will decline for even small temperature The media has a very important role in increases (1-2°C) the climate change arena. The media affects the public by bringing the issue to the attention of „ Commercial timber productivity may the public and by influencing public opinion on increase slightly with increased climate change through issue framing. temperatures, with large regional variability Many articles were written in response to the release of the report by WG I in early „ Changes in the distribution and February 2007. 9 These articles focused on the production of fish species are IPCC’s conclusions that climate change is expected with negative effects on “unequivocal” and that it is “very likely” caused aquaculture and fisheries by human activities.10 After the report of WG II 4) Coastal systems and low lying areas was released in April 2007, many articles appeared in national newspapers as well. 11 „ Increased coastal erosion due to These reports focused on the potential impacts of higher sea levels the proposed temperature increases, such as „ More frequent coral bleaching events droughts, flooding, rising sea level and food shortages. Extremely vulnerable regions, both „ Negative effects on coastal wetlands globally (mentioned in the previous section) and (salt marshes and mangroves) due to nationally, such as the Southwestern U.S., were sea level rise discussed in several reports. „ Low lying areas are extremely Criticisms of the IPCC vulnerable to flooding Several climate experts have expressed 5) Industry, settlement and society concerns about the lessened worst-case scenario for sea level rise in the new IPCC report (down „ Those in coastal and river flood plains 12 are the most vulnerable from 88 cm in the TAR to 59 cm in the AR4). The panel did not consider or include new „ Poor communities are also extremely evidence on the rate of melting of glaciers and vulnerable (limited adaptive capacity) the Greenland and West Antarctic ice sheets 6) Human health because there was a set deadline of December

„ Increases in malnutrition and 9 See Appendix I for a list of selected newspaper articles diarrhoreal diseases published around the release of the report from WG I. 10 greater than 90% certainty „ Increases in death and injury from 11 heat waves, floods, storms, fires, and See Appendix II for a list of selected newspaper articles published around the release of the report from WG II. droughts 12 Cornelia Dean, Andrew C. Revkin contributed „ Changes in the distribution of reporting.. Even Before Its Release, World Climate Report Is infectious disease vectors. Criticized as Too Optimistic. New York Times (Late Edition (east Coast)) [serial online]. February 2, 2007:A.11.

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2005 for the submission of scientific information. demonstrating the need for a comprehensive However, limitations such as this are often not global plan.14 discussed in the highly consulted and cited “Summary for Policymakers” of the Working Security Groups. This demonstrates the difficulty of Climate change is now being considered making scientific statements and predictions in a a security threat. A military panel of retired rapidly progressing field and reporting them in a generals and admirals released a report in April condensed summary report. This highlights one that said, “projected climate change poses a of the difficulties of an international panel serious threat to America’s national security.”15 involving many participants and a rigorous and This report describes climate change as a “threat lengthy review process. To remedy this problem, multiplier,” that may exacerbate instability it has been suggested that smaller groups be throughout the world. The United Nations formed to focus on particular aspects of climate Security Council also held a debate about the change and create special reports on a more impacts of climate change on peace and security 13 frequent basis. in April 2007.

CONSIDERATIONS FOR POLICYMAKERS APPENDIX I Considerations for Policymakers are Newspaper articles published around the vast and complex. Aside from the information included within the AR4, policymakers should release of WG I in February 2007. consider the following aspects of climate change. 1) Beth Daley Climate report faults humans for warming; Panel voices more certainty Spatial and Temporal Scale than in 2001 :[3 Edition]. Boston Climate change is a global phenomenon Globe [serial that should be addressed in a global context with online]. February 2, 2007:A.3. international cooperation. Although the regional 2) Beth Daley UN study spurs call to fight impacts of climate change vary, an international warming; Panel says rise is effort must be made to supply information and `unequivocal' :[3 Edition]. Boston technical expertise to developing nations to assist Globe [serial them with reducing their emissions or adapting online]. February 3, 2007:A.1. to the impacts of climate change. 3) ERIC BERGER Severe heat, drought Particular attention should be given to the predicted for life in 22nd-century Texas / fact that warming will occur over the next Global warming report also warns of more century due to the greenhouse gases already in flooding :[3 STAR , 0 Edition]. Houston the atmosphere. Therefore, adaptation and Chronicle [serial mitigation strategies are necessary to cope with online]. February 3, 2007:A.1. inevitable warming and sea level rise. Measures to reduce greenhouse gas emissions are also 4) Gautam Naik and Jeffrey Ball U.N. Report necessary to reduce future impacts of climate Adds Pressure to Global-Warming change. Fight. Wall Street Journal (Eastern Edition) [serial Economics online]. February 2, 2007:A.4. Efforts to reduce greenhouse emissions 5) Ian Sample, Science correspondent are often viewed to be perilous to the economy. National: IPCC report: Why the news about While the Bush administration accepts the recent warming is worse than we thought: findings of the IPCC, they oppose mandatory feedback: Oceans, soil and trees will reductions in greenhouse gas emissions because become worse at absorbing carbon dioxide of the potential damage to the U.S. economy. The administration warns of industries moving abroad, possibly to developing countries, to 14 Zachary Coile Report spurs calls for aggressive action / avoid stringent reductions in the U.S., again White House accepts findings but rejects mandatory cuts :[FINAL Edition]. San Francisco Chronicle [serial online]. February 3, 2007:A.6. 13 Oppenheimer, M., O’Neill, B.C., Webster, M., and 15 The Center Naval Analyses Corporation. 2007. National Agrawala, S. 2007. The Limits of Consensus. Science. 317: Security and the Threat of Climate Change, available at p1505-1506. http://SecurityAndClimate.cna.org/

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as temperatures rise: Evidence for warming: Monitor [serial what the scientists found. The online]. February 5, 2007:02. Guardian [serial 14) Peter N. Spotts Staff writer of The online]. February 3, 2007:12. Christian Science Monitor Reports on 6) James Bronzan Ever-Firmer Statements on global warming lag behind the science ; Global Warming. New York Times (Late The newest UN-sponsored assessment left Edition (east Coast)) [serial out research that suggests more dire climate online]. February 4, 2007:2. change :[ALL Edition]. The Christian Science Monitor [serial 7) Jane Kay A WARMING WORLD / online]. February 7, 2007:03. Climate Change Report / Grim global warming prognosis for Western U.S. / 15) SETH BORENSTEIN Report: Global International group says quick action can warming to last for centuries / Scientists mitigate some effects :[FINAL say it's `very likely' caused by people :[3 Edition]. San Francisco Chronicle [serial STAR , 0 Edition]. Houston online]. February 3, 2007:A.1. Chronicle [serial online]. February 2, 2007:1. 8) John J. Fialka Politics & Economics: Global-Warming Report Gets U.S. 16) Seth Borenstein, Associated Press Report Emphasis. Wall Street Journal (Eastern steps up warning on global warming threat ; Edition) [serial In strongest wording yet, humans get online]. February 3, 2007:A.4. blame :[Chicago Final Edition]. Chicago Tribune [serial 9) Katy Human Denver Post Staff Writer .N. online]. February 2, 2007:9. climate-change panel's projections for '01 borne out The earlier estimates were called 17) Thomas H. Maugh II and Karen Kaplan alarmist at the time, but updated data Deal with warming, don't debate it, indicate they were conservative :[Final scientists warn; The U.N.'s stark report puts Edition]. Denver Post [serial policymakers on notice, though there is no online]. February 2, 2007:A.4. consensus on action :[HOME EDITION]. Los Angeles Times [serial 10) MIKE TONER 'We're creating a different online]. February 3, 2007:A.1. planet': Scientists warn climate changes might worsen :[Main Edition]. The Atlanta 18) Zachary Coile Report spurs calls for Journal - Constitution [serial aggressive action / White House accepts online]. February 3, 2007:A.5. findings but rejects mandatory cuts :[FINAL Edition]. San Francisco 11) Patrick O'Driscoll Report says warming Chronicle [serial 'very likely' caused by people, will last online]. February 3, 2007:A.6. centuries :[FINAL Edition]. USA TODAY [serial 19) Cornelia Dean, Andrew C. Revkin online]. February 2, 2007:A.6. contributed reporting.. Even Before Its Release, World Climate Report Is 12) Peter N. Spotts Staff writer of The Criticized as Too Optimistic. New York Christian Science Monitor A clearer global Times (Late Edition (east Coast)) [serial climate forecast ; A report coming Friday online]. February 2, 2007:A.11. will offer the strongest consensus yet on how the Earth will change :[ALL 20) ELISABETH ROSENTHAL and Edition]. The Christian Science ANDREW C. REVKIN, Elisabeth Monitor [serial Rosenthal reported from Paris, and Andrew online]. February 1, 2007:01. C. Revkin from New York. Felicity Barringer contributed reporting from 13) Peter N. Spotts Staff writer of The Washington.. Science Panel Says Global Christian Science Monitor In wake of latest Warming Is 'Unequivocal'. New York climate report, calls mount for global Times (Late Edition (east Coast)) [serial response ; UN findings name human online]. February 3, 2007:A.1. activity as 'very likely' cause of 'unequivocal' climate change :[ALL 21) Global Warning; The world's scientists Edition]. The Christian Science agree, again, that climate change is a big

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problem :[FINAL Edition]. The 3) Beth Daley A CLIMATE CHANGE Washington Post [serial WARNING; Panel says humans are online]. February 5, 2007:A.14. probably causing shifts around world :[3 Edition]. Boston Globe [serial online]. 22) John Leicester, the Associated April 7, 2007:A.1. Press. Climate change report's forecast is bleak :[First Edition]. St. Louis Post 4) Beth Daley US lags on plans for climate Dispatch [serial change :[3 Edition]. Boston Globe [serial online]. February 4, 2007:A.5. online]. April 5, 2007:A.1. 23) Key players react to the IPCC global 5) Brad Knickerbocker White House expected warming report :[ALL Edition]. The to feel the heat from Supreme Court's Christian Science Monitor [serial ruling on global warming :[ALL Edition]. online]. February 8, 2007:25. The Christian Science Monitor [serial online]. April 5, 2007:10. 24) Melting doubts / The latest United Nations assessment of the human role in global 6) Dan Vergano Study forecasts new 'Dust warming should spur a U.S. search for Bowl' :[FINAL Edition]. USA TODAY solutions :[3 STAR , 0 Edition]. Houston [serial online]. April 6, 2007:A.8. Chronicle [serial 7) David Adam, Environment correspondent online]. February 3, 2007:B.6. Climate change will hit poorest hardest, say 25) Political climate shifts as verdict on UN scientists. The Guardian [serial warming arrives :[FINAL Edition]. USA online]. April 6, 2007:6. TODAY [serial 8) David Adam, Environment correspondent online]. February 2, 2007:A.8. Environment: UN: we have the money and 26) Seth Borenstein, THE ASSOCIATED know-how to stop global warming: Report PRESS. Global warming is here to stay obtained by the Guardian spells out strategy That's the message in a climate report by to reverse climate change. The Guardian the world's leading experts :[Third [serial online]. April 28, 2007:6. Edition]. St. Louis Post - Dispatch [serial 9) Ed Pilkington, New York UK to raise online]. February 3, 2007:A.22. climate talks as security council issue. The 27) Seth Borenstein, the associated Guardian [serial online]. April 16, 2007:24. press. Finger pointed at us all Climate panel 10) Jane Kay Report predicts climate calamity / agrees on most powerful warning yet, All continents face drought, starvation, saying human activities are "very likely" rising seas, panel says :[FINAL Edition]. causing rising seas and stronger San Francisco Chronicle [serial online]. hurricanes :[Third Edition]. St. Louis Post April 7, 2007:A.1. Dispatch [serial online]. February 2, 2007:A.1. 11) Joseph Schuman The Morning Brief: A Climate Report Brings Dire Warnings, and APPENDIX II Frustration :Online edition. Wall Street Journal (Eastern Edition) [serial online]. Newspaper articles published around the April 6, 2007: release of WG II in April 2007. 12) Juliet Eilperin - Washington Post Staff 1) ANDREW C. REVKIN and TIMOTHY Writer Climate Panel Confident Warming WILLIAMS Global Warming Called Is Underway; Report to Detail the Role of Security Threat. New York Times (Late humans :[FINAL Edition]. The Edition (east Coast)) [serial online]. April Washington Post [serial online]. April 5, 15, 2007:1.25. 2007:A.1. 2) Andrew C. Revkin Wealth and Poverty, 13) Juliet Eilperin - Washington Post Staff Drought and Flood: Reports From 4 Fronts Writer Military Sharpens Focus on Climate In the War on Warming. New York Times Change; A Decline in Resources Is (Late Edition (east Coast)) [serial online]. Projected to Cause Increasing Instability April 3, 2007:F.4. Overseas :[FINAL Edition]. The

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Washington Post [serial online]. April 15, create another Dust Bowl. Water politics 2007:A.6. could also get heated :[HOME EDITION]. Los Angeles Times [serial online]. April 6, 14) Juliet Eilperin - Washington Post Staff 2007:A.1. Writer Warming Predicted to Take Severe Toll on U.S :[FINAL Edition]. The 23) Alan Zarembo, Thomas H. Maugh II. Dire Washington Post [serial online]. April 17, warming report too soft, scientists say; 2007:A.12. Some nations lobbied for changes that blunt the study, contributors charge. The U.N. 15) Katy Human Denver Post Staff Writer forecast is still bleak :[HOME EDITION]. Flame-plagued summers part of climate Los Angeles Times [serial online]. April 7, forecast The next chapter of a report on 2007:A.1. global warming predicts a dried-out West battling more and more fires at a cost of 24) JAMES KANTER and ANDREW C. billions :[Final Edition]. Denver Post REVKIN, James Kanter reported [serial online]. April 3, 2007:B.4. fromBrussels, and Andrew C. Revkin from New York.. Scientists Detail Climate 16) Maggie Farley The World; U.N. discusses Changes, Poles to Tropics. New York climate change; Some Security Council Times (Late Edition (east Coast) [serial members say the issue isn't germane; others online]. April 7, 2007:A.1. argue that it threatens peace and security :[HOME EDITION]. Los Angeles 25) Many species feel impact of global Times [serial online]. April 18, 2007:A.8. warming, panel finds :[Fourth Edition]. St. Louis Post-Dispatch [serial 17) Marc Kaufman - Washington Post Staff online]. April 1, 2007:A.6. Writer Southwest May Get Even Hotter, Drier; Report on Warming Warns of 26) Andrew C. Revkin. "U.N. Draft Cites Droughts :[FINAL Edition]. The Humans in Current Effects of Climate Washington Post [serial online]. April 6, Shift. " New York Times [New York, 2007:A.3. N.Y.] 5 Apr. 2007, Late Edition (East Coast): A.6. 18) Mark Magnier THE WORLD; U.N. report raises pressure on China to cut pollution; 27) Karen Kaplan, Thomas H. Maugh II. "The Economic growth has brought Nation; Military panel calls global warming environmental disaster, but fixing it is a security threat; Food shortages, melting complicated by politics, poverty and ice and natural disasters pose danger, report tradition :[HOME EDITION]. Los Angeles says :[HOME EDITION]. " Los Angeles Times [serial online]. April 8, 2007:A.3. Times [Los Angeles, Calif.] 17 Apr. 2007,A.16. 19) Mark Martin Legislature flooded with bills about climate crisis / Poll-driven politicians see need to tackle global warming :[FINAL Edition]. San Francisco Chronicle [serial online]. April 2, 2007:A.1. 20) Peter N Spotts Surviving a warmer world: Global forecast is 'mostly dry' :[ALL Edition]. The Christian Science Monitor [serial online]. April 5, 2007:1. 21) A Consensus on Crisis; A U.N. panel details the distress that global climate change might cause human societies :[FINAL Edition]. The Washington Post [serial online]. April 8, 2007:B.6. 22) Alan Zarembo, Bettina Boxall. The Nation; A permanent drought seen for Southwest; A study says global warming threatens to

7 on the climate over time periods longer than 1 Paleoclimate overview report million years. Matt Distler Other factors affect the earth’s climate on smaller temporal scales, however, including EXECUTIVE SUMMARY changes in ocean circulation, atmospheric green- Earth’s climate over the last 1 million years house gas concentrations, terrestrial albedo con- has changed on a 100,000 year (100 ka) cycle, ditions, vulcanism, asteroid impacts, and many driven by parameters related to earth’s orbit. Ice others. There is accumulating evidence that the core data now covers the last 8 cycles, revealing climate is currently warming, and that increases a repeated pattern of gradual cooling into 100 ka in anthropogenically produced greenhouse gases, glacial periods followed by rapid warming to 8 especially carbon dioxide (CO2), may be a pri- ka to 28 ka interglacial conditions like those ex- mary driver of this change (Mayewski and White, perienced today. New ice core evidence shows 2002). the interglacial of 410 ka, like our current inter- Paleoclimatic reconstructions provide im- glacial, was particularly long (~28 ka), suggest- portant clues as to the past interactions between ing that orbital parameters do not necessarily these factors, orbital parameters, and past climate predict an imminent return to glacial conditions. change, allowing us to better predict the trajec- Paleoclimate research in the last several tory of the modern climate. Ice cores in particu- decades has better characterized rapid climate lar are important data sources for paleoclimatic change events superimposed upon the long-term reconstructions, due to their high temporal reso- orbital-driven cycle. Ice core data from lution and the direct inclusion of atmospheric Greenland reveals that these events, including components, including CO2, in the ice. Other the Little Ice Age (LIA) in the last 200 years, are characteristics of ice and included impurities, characterized by significant changes in tempera- such as dust or ice density, serve as climate prox- ture and climate over continental or global scale ies, telling us more about weather conditions in and may initiate within decades. These events the past. This report endeavors to give an over- are often triggered by changes in ocean circula- view of the recent advances in our knowledge of tion, including changes to the strength of the paleoclimates based on ice core data, and dis- Atlantic thermohaline circulation system. In ad- cusses the implications of this research for future dition, Greenland ice core data show that the climate change. circulation patterns characteristic of the LIA have not ended, despite increased global tem- STATE OF THE SCIENCE peratures, implying possible anthropogenic, not Recent ice cores in the Antarctic have ex- orbital, causes of warming. tended the length of our high resolution ice core records to approximately 800 ka (EPICA, 2004), INTRODUCTION improving our understanding of the very long- The degree and timing of Earth’s tilt on term changes in the orbital climate cycles of it’s axis as it circles the sun and the shape of its earth. The new records corroborate the general orbit are the major drivers of earth’s climate on a pattern of temperature and greenhouse gas con- multi-millenial timescale. The eccentricity centration changes seen in previous records of (variation from circular) of earths orbit around recent glaciations; glacial periods are character- the sun produces a 100,000 year (100 ka) cycle ized by slowly decreasing temperatures and CO2 of greater and lesser insolation, the obliquity (tilt) concentrations culminating in a period of cold of the orbit drives a 41 ka cycle, and the preces- but variable climate lasting approximately 100 sion (timing of seasons relative to orbital dis- ka. Glacial periods then transition more abruptly tance from sun ) driving a 22 ka cycle of varying to a warmer interglacial similar to our current seasonality. Together these parameters produce Holocene period. an approximately 100 ka cycle of glacial and The recent long Antarctic cores extend interglacial periods that have characterized the back to four glacial cycles not yet observed in ice earth’s climate for much of the last million years. cores, and show that the oldest of these glacial The changing position of continents, which dra- periods seem increasingly driven by the two matically affect ocean and heat circulation shorter (41ka, 22ka) orbital cycles, and that in- around the globe may have played a crucial part terglacials were cooler during this period. This in modulating the effects of these orbital cycles change in the orbital cycles toward beginning of DISTLER PALEOCLIMATE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 the last 1 million years is in keeping with sedi- with warmer northern European winters. This ment core results, but is not yet completely un- effect is due to a “seesaw” of high pressure sys- derstood. Another new finding is the extended tems affecting the paths of cold air across the length of the interglacial period that occurred north Atlantic. Ice core data from Dawson’s 410 ka ago, the first cycle beyond the reach of team in Greenland match historical temperature earlier ice cores. The three more recent intergla- records well and show that colder years in cials we’ve studied up until these new data have Greenland are also associated with greater so- all been approximately 8 ka in length, which dium (Na+) deposition from sea salts, a marker of suggested that the current 10 ka length of our increased storminess. Furthermore, the period own Holocene might require a non-orbital-driven from 1400 A.D. to 1900 A.D., a widespread cold explanation, such as early agricultural period known as the Little Ice Age (LIA) is char- CO2/methane emissions. The recently revealed acterized by more frequent storms in Greenland 410 ka interglacial, however, was approximately (despite the inverse year-by-year correlation be- 28 ka in duration (before agriculture and without tween temperatures in Greenland and Europe). an accompanying rise in CO2), showing that or- This study shows that the degree of storminess in bital parameters may be able to explain our long Greenland is a good indicator of RCCE cooling Holocene (EPICA, 2004; White, 2004). in Europe and possibly other parts of the world. Interestingly, the return to a warmer post-LIA High resolution ice cores from Greenland climate ~1900 A.D. is not accompanied by a (GISP2 project) are informative about recent resumption of the storm circulation patterns from climatic changes, particularly the speed with the previous warm period. Rather, LIA patterns which major climate change can occur. Johnsen in the ice core continue to the present (Dawson et and others (1992) compare the results of four al. 2003; Mayewski and White, 2002.), despite Greenland ice cores, and show conclusively that the global warming of approximately 1 degree C short (0.5 to 2 ka) periods of warm interstadial since the turn of the 19th century. These data conditions occurred irregularly and repeatedly provide some evidence that the LIA atmospheric during the latter part of the last glaciation. From conditions continue, but that anthropogenic ef- the raised δ18O values (signifying increased tem- fects on climate have cancelled out the LIA cool- peratures) these interstadials appear to be charac- ing (Mayewski and White 2002). terized by temperatures ~7ºC warmer than the cold glacial conditions, only 5-6 ºC cooler than modern Greenland temperatures. Perhaps more PERSPECTIVES IN THE MEDIA AND PUBLIC importantly, annual resolution records confirm POLICY earlier speculation that these warm periods initi- Compared to news of current changes in ate abruptly, within a few decades. Subsequent weather, temperature, organisms’ reaction to cooling to glacial conditions was a more gradual weather, or even output from predictive climate process. These RCCEs and later ones during the models, paleoecological research is less often recent interglacial have been linked to changes in presented in the popular press. This may be due Atlantic Ocean circulation, which may be slowed to the indirect connection between paleoecologi- or stopped by increased freshwater input from cal findings and our predictive capabilities for melting glaciers during periods of warming future climate as well as the highly technical (Mayewski and White 2002). The speed of these nature of paleoclimatic techniques and results. changes suggests that the climate systems is Nonetheless, there are a number of sources that more dynamic and variable at a shorter temporal have brought paleoecological data to the public scale than previously thought. eye. Examples include The Weathermakers (Flannery, 2005), portions of Al Gore’s (2006) Greenland ice cores, coupled with long- An Inconvenient Truth, the IPCC summary for term observational data on weather across the policymakers, and a few popular books specifi- North Atlantic, have also shed light on relatively cally about paleoclimate. recent (historical) climate change, helping to sort out the influences of human civilization on the Flannery’s book uses paleoecological climate versus the suite of orbital, solar, and sources to place current climate in perspective other “natural” influences on climate. Dawson and highlights some paleo-events as analogs for and others (2003) compared temperature records future change, including the massive release of from Greenland and Northern Europe dating methane at the Paleocene-Eocene boundary, 55 back to the 1880s, confirming earlier observa- million years ago. An Inconvenient Truth pro- tions that cold Greenland winters are associated vides greenhouse gas data from ice cores, but,

2 DISTLER PALEOCLIMATE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 like many popular sources, simplifies the results ready offset Little Ice Age conditions. This to make a more forceful point. Gore shows that research adds to the vast and growing body modern CO2 levels are well above past Pleisto- of evidence for anthropogenic effects on cene levels, but fails to explain complex feed- the climate, all of which represents a seri- backs between CO2 levels and global tempera- ous argument for reducing greenhouse gas ture, leading to confusion about cause and effect. emissions, improving our ability as a civili- The IPCC summary for policymakers (2007) zation to adapt to changing climate and focuses on paleoecological estimates of sea level pursuing possible technologies to remediate rise in past interglacials, past variability in CO2 greenhouse gas effects. and other greenhouse gas levels from ice cores, and past estimates of temperature. A few popular REFERENCES books are directed entirely toward paleoecologi- Alley, R.B. 2000. The Two-mile Time Machine: cal findings, including The Ice Chronicles Ice Cores, Abrupt Climate Change, and Our (Mayewski and Frank, 2002) and The two-mile Future. Princeton University Press. time machine (Alley, 2000), allowing more com- prehensive discussion and summary of this com- An inconvenient Truth. 2006. (Film) Dir. D. plex field. Guggenheim. Perf. A. Gore. Lawrence Bender Productions. CONSIDERATIONS FOR POLICYMAKERS The science outlined above is part of a Dawson, A.G. L.Elliott, P. Mayewski, P. Lockett, growing body of paleoecological literature that S. Noone, K. Hickey, T. Holt, P. Wadhams, aims to better describe the history of earth’s past and I. Foster. 2003. Late-Holocene North climate changes in order to better understand Atlantic climate ‘seesaws’, storminess future change. Some of the most important les- changes and Greenland ice sheet (GISP2) sons from these studies are these: palaeoclimates. The Holocene, 4 (13): 381 - 392. Abstract: The oxygen-isotope record of pa- 1) Earth’s climate is continuously variable, laeotemperature from Greenland ice cores undergoing change at all temporal scales has for many years been the kingpin of cli- (gradual and rapid, short and long-term). mate reconstructions for the North Atlantic Our civilization needs to strengthen its abil- region and northern Europe, An air tempera- ity to adapt to oncoming climate change. ture, 'seesaw' between Greenland and north- 2) Major climate change, particularly warming, ern Europe. first described in AD 1765, is may happen very quickly, within a century also well known and is related to the North or even decades. Certain periods (for in- Atlantic Oscillation (NAO). Whereas the stance, the last glacial period) may be more NAO index series is based on instrumental prone to these major, rapid changes, but records of air pressure, the North Atlantic there is evidence that they re-occur ap- climate 'seesaw' has conventionally been proximately every 1400 years (Mayewski based on air-temperature records, Here we and White, 2002). This instability of our describe relationships between this 'seesaw' climate system on short timescales should mechanism and the Greenland (GISP2) oxy- cause us to work on improving our adapta- gen-isotope chronology of air-temperature bility to such changes, but also caution us variations, as well as relationships between to avoid any anthropogenic impacts that GISP2 Na+ (sea-salt) variations and instru- might set off feedbacks that bring on mental records of North Atlantic storminess. RCCEs (such as causing significant melting The GISP2 proxy air-temperature record is of polar/arctic freshwater into the North At- calibrated for the last 130 years with instru- lantic). mental weather records for West Greenland, while the Na+ series is compared with in- 3) Human impact on climate may already be strumental records of North Atlantic stormi- observable in paleoecological records. Al- ness change. Reconstruction of an annual se- though new Antarctic cores suggest our ries of these climate parameters for the last current interglacial may be long due to or- 1000 years shows that during the 'Mediaeval bital forcing, not anthropogenic influences Warm Period' there were no years character- beginning ~10 ka, Greenland cores suggest ized by high Na+ extremes (high North At- our impact since ~1900 A.D. may have al-

3 DISTLER PALEOCLIMATE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

lantic storminess) but there were many years Report of the Intergovernmental Panel on Climate when there were extremes of temperature. Change [Solomon, S., D. Qin, M. Manning, Z. Chen, Remarkably, there A ere no years of excep- M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, tionally low air temperature and high Na+ United Kingdom and New York, NY, US. precipitation at GISP2 between AD 1650 and 1710. a period of time that in northern Flannery, Tim. 2005. The Weathermakers. At- Europe incorporates the period of maximum lantic Monthly Press, New York. 'Little Ice Age' cooling. It would appear also that for the last thousand years the most ex- Johnsen, S.J., H.B. Clausen, W. Dansgaard, K. treme 'seesaw' winters when GISP2 tem- Fuhrer, N. Gunderstrup, C.U. Hammer, P. peratures were very low and Na+ concentra- Iversen, J. Jouzel, B. Stauffer, and J.P, tions were high occurred in discrete clusters Steffensen. 1992. Irregular glacial intersta- and pairs of years. dials recorded in a new Greenland ice core.

Nature 359: 311-313. EPICA community members*. 2004. Eight gla- Abstract: The Greenland ice sheet offers the cial cycles from an Antarctic ice core. Na- most favourable conditions in the Northern ture 429: 623-628. Hemisphere for obtaining high-resolution Abstract: The Antarctic Vostok ice core continuous time series of climate-related pa- provided compelling evidence of the nature 18 16 rameters. Profiles of O/ O ratio along of climate, and of climate feedbacks, over 1–3 three previous deep Greenland ice cores the past 420,000 years. Marine records sug- seemed to reveal irregular but well-defined gest that the amplitude of climate variability episodes of relatively mild climate condi- was smaller before that time, but such re- tions (interstadials) during the mid and late cords are often poorly resolved. Moreover, it parts of the last glaciation, but there has is not possible to infer the abundance of been some doubt as to whether the shifts in greenhouse gases in the atmosphere from oxygen isotope ratio were genuine represen- marine records. Here we report the recovery tations of changes in climate, rather than ar- of a deep ice core from Dome C, Antarctica, tefacts due to disturbed stratification. Here that provides a climate record for the past we present results from a new deep ice core 740,000 years. For the four most recent gla- drilled at the summit of the Greenland ice cial cycles, the data agree well with the re- sheet, where the depositional environ-ment cord from Vostok. The earlier period, be- and the flow pattern of the ice are close to tween 740,000 and 430,000 years ago, was ideal for core recovery and analysis. The re- characterized by less pronounced warmth in sults reproduce the previous findings to such interglacial periods in Antarctica, but a a degree that the existence of the interstadial higher proportion of each cycle was spent in episodes can no longer be in doubt. Accord- the warm mode. The transition from glacial ing to a preliminary timescale based on to interglacial conditions about 430,000 stratigraphic studies, the interstadials lasted years ago (Termination V) resembles the from 500 to 2,000 years, and their irregular transition into the present interglacial period occurrence suggests complexity in the be- in terms of the magnitude of change in tem- haviour of the North Atlantic ocean circula- peratures and greenhouse gases, but there tion. are significant differences in the patterns of

change. The interglacial stage following Mayewski, P. and F. White. 2002. The Ice Termination V was exceptionally long - chronicles. University Press of New Eng- 28,000 years compared to, for example, the land. 12,000 years recorded so far in the present

interglacial period. Given the similarities be- White, J.W.C. 2004. Do I hear a million? Sci- tween this earlier warm period and today, ence 304: 1609-1610. our results may imply that without human intervention, a climate similar to the present *Laurent Augustin1, Carlo Barbante2, Piers R. F. one would extend well into the future. Barnes3, Jean Marc Barnola1, Matthias Bigler4, Emiliano Castellano5, Olivier Cattani6, Jerome IPCC, 2007: Summary for Policymakers. In: Climate Chappellaz1, Dorthe Dahl-Jensen7, Barbara Del- Change 2007: The Physical Science Basis. Contri- monte1,8, Gabrielle Dreyfus6, Gael Durand1, bution of Working Group I to the Fourth Assessment Sonia Falourd6, Hubertus Fischer9, Jacqueline Flu¨ ckiger4, Margareta E. Hansson10, Philippe

4 DISTLER PALEOCLIMATE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

Huybrechts9, Ge´ rard Jugie11, Sigfus J. Johnsen7, Jean Jouzel6, Patrik Kaufmann4, Josef Kipfstuhl9, Fabrice Lambert4, Vladimir Y. Lipenkov12, Genevie` ve C. Littot3, Antonio Longinelli13, Reginald Lorrain14, Valter Maggi8, Valerie Mas- son-Delmotte6, Heinz Miller9, Robert Mulvaney3, Johannes Oerlemans15, Hans Oerter9, Giuseppe Orombelli8, Frederic Parrenin1,6, David A. Peel3, Jean-Robert Petit1, Dominique Raynaud1, Cath- erine Ritz1, Urs Ruth9, Jakob Schwander4, Urs Siegenthaler4, Roland Souchez14, Bernhard Stauffer4, Jorgen Peder Steffensen7,

5 depleted (Orr, et. al., 2005). Research is cur- Ocean Acidification rently needed in many areas to gain a better un- derstanding of how much time we have to possi- Effects of Anthropogenic CO2 on Marine bly mitigate current damage and prevent future Calcifying Organisms, Ocean Water Chem- damage to oceans and calcifying organisms. istry and What the Future has in Store… Although there is much we do not know Kacie Gehl concerning the process, we do know that the net source of carbon to the oceans is of an anthropo- EXECUTIVE SUMMARY: genic nature. As the IPCC defines, even at a Anthropogenic release of carbon diox- zero emissions standstill in CO2 pollution, the ide into the atmosphere is affecting the oceans oceans will continue to take up carbon dioxide profoundly. The oceans are the main source of because this system is lagging behind. Also, we carbon sequestration on the planet and without do know that we can not reverse what we have this storage; the planet may be currently unin- already released into the oceans; we can only habitable. As the oceans take up carbon dioxide, look to the future. With this in mind, without it combines with calcium ions to produce car- knowing anymore than we do about ocean acidi- bonic acid (Orr, et. al., 2005). This, in effect, fication, it seems the answer is to bring emis- decreases the alkalinity of the oceans. With ris- sions down and as close to zero as possible (Orr, ing levels of undersaturation, there is a move to et. al., 2005). more acidic ocean waters (Orr, et. al., 2005), (Feely, et. al., 2004). The slight change creates STATE OF SCIENCE: an environment that is devastating for marine The saturation state of calcium carbonate in calcifying organisms. Because there is a de- the “business as usual” scenario of the IPCC is pleted amount of calcium in the ocean water, undersaturated. Undersaturation of seawater, calcifying organisms such as pteropods and cor- which is the decrease in calcium saturation and als are no longer able to maintain or produce thus more acidic water, though still at pH levels shells or skeletons (Orr, et. al., 2005), (Hughes, greater than 7.0, will likely occur within fifty et. al., 2003). This disrupts the basis of the food years in some polar and sub polar surface waters chain in many ecosystems. As the oceans can (Orr, et. al., 2005). It is predicted that this only sequester a specific amount of carbon diox- change in chemistry will occur most drastically ide of which the value is unknown, it is of the in the higher latitude oceans due to the presence utmost importance to understand as completely of seasonality in these areas as opposed to equa- as possible, the effects of acidification of the torial regions. In winter, the waters are cooled oceans on calcifying organisms and the thresh- and there is a higher amount of dissolved CO2. olds that exist concerning where and when the Due to these factors, undersaturation of calcium most abrupt changes in calcium saturation will will occur in these waters first during winter. As occur. calcium binds with CO2, carbonic acid forms thus making the water more acidic. However, this INTRODUCTION: process uses up the calcium in the water that Changes in ocean water chemistry occur would be used to form and maintain the shells from the deposition of atmospheric carbon diox- and skeletons of marine calcifying organisms ide into the oceans. This process enables life on such as pteropods and corals (Orr, et. al., 2005). land to exist more comfortably as we would have These species are critical to food webs and have a much warmer and less pleasant climate without a difficult time migrating because in many cases, this sequestration. When the critical threshold is they can survive only in specific habitats and the reached, in which the oceans will be a net source availability of these habitats is lessening each of carbon, the climate will warm at a greater ex- day. tent. However, already, effects in the oceans are Supporting research shows that through evident. Marine calcifying organisms, which analyzing aragonite and calcite saturation values form the basis of many food chains, are strug- and quantifying calcium carbonate dissolution, gling to survive. As CO2 depletes the free cal- saturation horizons are migrating (Feely, et. al., cium ions in the water and becomes carbonic 2004). Results showed that in the southeastern acid, calcifying organisms are no longer able to and northeastern Atlantic Ocean, the saturation build new shells or maintain the ones they cur- horizon for aragonite moved up between 80 and rently have, because their source of calcium is GEHL OCEAN ACIDIFICATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

150 meters. In the Pacific Ocean, the horizon is shows how each of the IPCC emissions scenarios between 30 and 80 meters south of 38 degrees lead ultimately to more acidic oceans because we south and between 30 and 100 meters north of 3 cannot reverse the process of carbon sequestra- degrees north latitude (Feely, et. al., 2004). tion; we can only slow it down. She acknowl- Again, we see that the saturation horizon is be- edges that if the oceans did not sequester the coming shallower in the higher latitude oceans. majority of the carbon dioxide that we emit, then This leaves much narrower spaces for species to the earth would be at a heightened state of warm- thrive and survive (Feely, et. al., 2004). ing currently. This sequestration leaves us an opportunity to reduce or aim for zero emissions Climate change has caused three major and create a lag to disrupt the rate of acidifica- threats to the health of coral reefs. These include tion. This will give us more time to research the ocean uptake of atmospheric carbon dioxide, issue. increased amount of hurricanes and warming waters. Ocean uptake of CO2 leads to more However, Kolbert does not address the acidic waters which impede the ability of corals frightening reality that the oceans will only se- to maintain and form their shells. Hurricanes quester a certain amount of carbon dioxide be- destroy corals with damaging currents. Warming fore they become saturated and are no longer to waters enable bleaching and disease among cor- buffer our emissions. At this point, which is als (Hughes, et. al., 2003). unidentified, the oceans will become a net source of carbon (Kolbert, 2006). This occurs as the One model assumes corals respond the oceans reach their capacity with how much car- same to similar stresses and that corals can not bon they can hold and begin to release carbon to adapt to changes in temperature. This has been compensate. This release, coupled with our high questioned by noting that bleaching of corals is emissions, will increase the rate of warming and patchy indicating that not all corals respond the climate change. same to temperature or chemistry stressors (Hughes, et. al., 2003). Perhaps the general media opinion was aimed at giving people hope that with a zero In addition, bleaching has been thought to emissions policy, we may be able to counter the be “adaptive”. However, it has been shown that damage we have created. bleaching in corals is a response to environ- mental stressors such as warming, pH differences, and chemistry differences rather than an adaptive CONSIDERATIONS FOR POLICYMAKERS: measure (Hughes, et. al., 2003). With all of this information, policymakers should produce emissions management plans Although it is unknown whether corals can with an end product of low-zero emissions. Ef- evolve to adapt to warming climates and changes forts currently underway by governments include in ocean water chemistry, it may be possible and laws and incentives for green lifestyles. Treaties further research must be conducted. Even if evo- and voluntary carbon reduction programs are lution can occur at such a quick rate, it is uncer- beginning to show the world’s interest in reduc- tain whether genetic traits will be inherited that ing emissions. However, many of these efforts will enable corals to survive. Perhaps, if corals are treating the symptom, not the problem. To evolve to be more tolerant of warmer tempera- begin to give ourselves enough time, we must tures, they will be less tolerant of higher pH val- implement a low emissions target. This notion is ues. These are considered life history tradeoffs. justified by the IPCC in their IPCC S650 stable It is impossible to know more about these trade- rate emissions model versus their business as offs without more studies and even then, the fu- usual model IPCC IS92a (IPCC, 2007). ture is uncertain (Hughes, et. al., 2003). Also, to help sustain corals, better man- PERSPECTIVES IN MEDIA AND PUBLIC agement practices need to be implemented con- POLICY: cerning no-take areas. The main threats to corals are not mitigated by small no-take areas. Al- Elizabeth Kolbert’s, The Darkening Sea, though no-take zones can not protect corals from highlights the deteriorating shells of pteropods warming waters and ocean acidification, they can while explaining sea water chemistry as the cul- protect them from direct human intervention. prit for the disintegration. Kolbert relates that These areas must encompass the majority of the anthropogenic emissions are the cause of the reefs they are meant to protect if they are to be trend toward more acidic ocean waters. She successful. However, without limiting emissions

2 GEHL OCEAN ACIDIFICATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 and giving corals an opportunity to evolve, mi- Abstract: The diversity, frequency, and grate or adjust, there is little hope that no-take scale of human impacts on coral reefs are in- areas alone will do the job (Hughes, et. al., 2003). creasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide In addition to lowering emissions, funding and temperature over the next 50 years exceed research to further the breadth of knowledge the conditions under which coral reefs have concerning ocean water chemistry and impacts flourished over the past half-million years. How- on calcifying organisms is critical. Understand- ever, reefs will change rather than disappear en- ing the thresholds that exist in the ocean chemis- tirely, with some species already showing far try and within ecosystems will give us clues as to greater tolerance to climate change and coral how much time we have to make changes before bleaching than others. International integration the oceans are only inhabitable by jellyfish and of management strategies that support reef resil- the main buffer of our carbon emissions becomes ience need to be vigorously implemented, and a source. complemented by strong policy decisions to re- There are many social conflicts and techni- duce the rate of global warming. cal uncertainties associated with reducing emis- IPCC, 2007: Summary for Policymakers. In: sions. Will our society crash without fossil fuel Climate Change 2007: The Physical Science usage? If we plan accordingly to use our deplet- Basis. Contribution of Working Group I to the ing natural resources to define a new society of Fourth Assessment Report of the Intergovern- “green technology” in which emissions are dras- mental Panel on Climate Change [Solomon, S., tically reduced, there is hope that the pace of D. Qin, M. Manning, climate change will slow and the quality and health of our environment will improve. In the Z. Chen, M. Marquis, K.B. Averyt, mean time, the delicate ecosystems of our oceans M.Tignor and H.L. Miller (eds.)]. Cambridge are fighting to survive. University Press, Cambridge, United Kingdom and New York, NY, USA.

Kolbert, E. (2006). "The Darkening Sea." CITED REFERENCES WITH ABSTRACTS: The New Yorker 82(38). Feely, R. A., C. L. Sabine, et al. (2004). Orr, J. C., V. J. Fabry, et al. (2005). "An- "Impact of anthropogenic CO2 on the CaCO3 thropogenic ocean acidification over the twenty- system in the oceans." Science 305(5682): 362- first century and its impact on calcifying organ- 366. isms." Nature 437(7059): 681-686. Abstract: Rising atmospheric carbon diox- Abstract: Today's surface ocean is satu- ide (CO2) concentrations over the past two cen- rated with respect to calcium carbonate, but in- turies have led to greater CO2 uptake by the creasing atmospheric carbon dioxide concentra- oceans. This acidification process has changed tions are reducing ocean pH and carbonate ion the saturation state of the oceans with respect to concentrations, and thus the level of calcium calcium carbonate (CaCO3) particles. Here we carbonate saturation. Experimental evidence estimate the in situ CaCO3 dissolution rates for suggests that if these trends continue, key marine the global oceans from total alkalinity and organisms - such as corals and some plankton - chlorofluorocarbon data, and we also discuss the will have difficulty maintaining their external future impacts of anthropogenic CO2 on CaCO3 calcium carbonate skeletons. Here we use 13 shell forming species. CaCO3 dissolution rates, models of the ocean - carbon cycle to assess cal- ranging from 0.003 to 1.2 micromoles per kilo- cium carbonate saturation under the IS92a 'busi- gram per year, are observed beginning near the ness-as-usual' scenario for future emissions of aragonite saturation horizon. The total water anthropogenic carbon dioxide. In our projections, column CaCO3 dissolution rate for the global Southern Ocean surface waters will begin to be- oceans is approximately 0.5 +/- 0.2 petagrams of come undersaturated with respect to aragonite, a CaCO3-C per year, which is approximately 45 to metastable form of calcium carbonate, by the 65% of the export production of CaCO3. year 2050. By 2100, this undersaturation could Hughes, T. P., A. H. Baird, et al. (2003). extend throughout the entire Southern Ocean and "Climate change, human impacts, and the resil- into the subarctic Pacific Ocean. When live pter- ience of coral reefs." Science 301(5635): 929- opods were exposed to our predicted level of 933. undersaturation during a two-day shipboard ex-

3 GEHL OCEAN ACIDIFICATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 periment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as sug- gested previously.

4 have dire consequences for the surrounding Changes to the Cryosphere populations. Changes in sea ice may have some positive effects, such as opening new trade Brandon Murphy routes, but also negative consequences for the animals that live and depend on the ice. The loss EXECUTIVE SUMMARY of permafrost can wreak human infrastructure as Changes to the frozen surfaces of the the ground begins to subside, but may also cause earth provide some of the most visible evidence a shift in vegetation which can create a carbon of a shifting climate. Glaciers are shrinking sink. throughout the world, and the two largest ice sheets, Greenland and Antarctica, are experienc- The melting of glaciers and ice caps is a ing a negative mass balance of ice. This loss of topic very commonly associated with global cli- continental ice is contributing to the rise of sea mate change. The recession of glacial terminal level. The loss of mass from inland glaciers is ends, and the thinning of snow and ice pack are a occurring more rapidly than from the ice sheets, favorite visualization of the warming climate in and threatens both communities that depend of the media. The rise of sea level associated with them for sources of water and communities that the glacial melt water to the is also a common depend on them for sources of income. topic in the popular media, although in reality it is a much smaller contributor to sea level rise Sea ice is steadily decreasing in extant than the thermal expansion of water. Before during summer at a rate of 4% per decade, which delving into any discussion on the cryosphere it will have a negative impact on those animals that is helpful to clarify a few common (and often are adapted to living on it. The opening of Arc- interchanged) terms. The American Meteoro- tic waters also creates new opportunities for hu- logical Society Glossary of Meteorology defines man economic gain through fishing, resource a glacier as “a mass of land ice, formed by the extraction, and new trade routes. However, there further recrystalization of firn (compacted, meta- is the possibility that access and rights to these morphosed old snow), flowing continuously waters may be a source of conflict in the future. from higher to lower elevations.” AMS defines The loss of permafrost will affect hu- an ice cap as, “a dome-shaped perennial cover of man infrastructure as the ground subsides. The ice and snow over an extensive portion of the loss of permafrost in peatlands may have posi- earth’s surface.” AMS defines an ice sheet as, “a tive and negative effects on the rate to climate continuous sheet of land ice that covers a very change. Peatlands are large storage pools of large area and moves outward in many direc- carbon and many are located in permafrost re- tions,” which is so thick that it will, “mask the gions. Depending on shifting climate patterns, at land surface contours.” In general, both ice caps least some areas may become carbon and radia- and ice sheets refer to bodies of ice so large that tive forcing sinks as they become more produc- they can cover mountains, and therefore flow radially. The distinction is sometimes drawn at tive. However, there may be a lag in this effect 2 2 during which the peatland becomes a radiative 50,000 km (19,300 mi ) between the smaller ice forcing source because of increased methane cap and the larger ice sheet. production. If some of these thawing peatlands Permafrost consists of all the ground also become drier because of changing climate, that is frozen year round for at least two years. then they will likely become sources of carbon. Permafrost underlies about 24% of the Northern Hemisphere’s land surface (Turetsky et al. 2007). INTRODUCTION These northern climates also support substantial The cryosphere consists of all the fro- peatlands. These northern peatlands are a sub- zen parts of the earth, such as glaciers, ice caps, stantial carbon pool, estimated to range from 42 ice sheets, sea ice, and areas of land underlain by to 489 Pg C (Turetsky et al. 2007), which repre- permafrost. Recent warming trends associated sents 20-30% of all global soil C (Johansson et al. with anthropogenic climate charge are reducing 2006). Concerns have been raised that as some the extent of these frozen areas. There are many of these peatlands that have been frozen begin to implications associated with changes in the thaw, they will turn into carbon sources as the cryosphere. The melting of large bodies of con- peat decays. However, there is new evidence tinental ice contributes to the rise of sea level. In that suggests that some of these peatlands will some areas, glacial melt is an important source of not dry out when they thaw but instead increase water, and the potential loss of glaciers could in productivity creating more carbon sinks MURPHY CRYOSPHERE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

(Camill et al. 2001; Johansson et al. 2006; Turet- culating a mass balance involves measuring the sky et al. 2007). changes in weight of a body of ice by measuring changes in the earth’s field of gravity using STATE OF THE SCIENCE NASA’s Gravity Recovery and Climate Experi- It is estimated that there may be as ment (GRACE) satellites. The premise behind many as 170,000 glaciers in the world, and of the gravimetric technique is that the greater the them only about 300 have been studied for mass at any point on the earth, the stronger its changes in mass balance for any length of time field of gravity. The measurements made by the (Barry 2006). Only 50 or so of the 300 glaciers GRACE satellites need to be corrected for have records going back more than 20 years. isostatic rebound, atmospheric mass, and exter- There are a number of ways in which glaciers are nal signals from continental hydrology outside monitored. The most common has been changes the area being measured and ocean mass vari- in the location of the glacial terminus. However, ability (Velicogna & Wahr 2006). The gravimet- the glacial terminus is not necessarily the best ric technique, which only began in 2002, is par- representation of true changes in mass and vol- ticularly useful for calculating mass budget on ume of a glacier because glaciers may thin more very large areas such as the Greenland ice sheet, rapidly than they recede (Barry 2006). and the Antarctic ice sheet. There are three main techniques used to The calculation of mass budget for the calculate a mass balance (Rignot & Thomas three main ice sheets from GRACE satellites’ 2002). The mass budget method is calculated data generally shows a net loss of ice in recent years. The Greenland ice sheet had a total loss of from estimates of all inputs and outputs to a gla- 3 cier or ice sheet. Outputs include melt, sublima- 82 + 28 km ice per year from 2002-2004 (Veli- cogna & Wahr 2005). The West Antarctic ice tion, flow, calving, which are all dynamic proc- 3 esses. The uncertainties with all the estimations sheet had a loss of 148 + 21 km per year, and the East Antarctic ice sheet had a change of 0 + of the inputs and outputs can lead to error in the 3 mass budget calculation, particularly on larger 56 km per year from 2002-2005 (Velicogna & areas of ice. The second method for mass bal- Wahr 2006). There is a general consensus ance is measurements of elevation change over among different mass balance techniques that time. The changes in elevation can then be con- both Greenland and Antarctica are currently ex- verted into estimates of changes in volume. The periencing a net loss of ice (table 1) changes in elevation are measured by laser al- timetry from either satellites or aircraft, and must first be corrected to account for isostatic rebound of the earth’s surface. The third method of cal-

Table 1. Summary of mass balance studies of the East Antarctic ice sheet (EAIS), West Ant- arctic ice sheet (WAIS), total Antarctic ice sheets (AIS), and the Greenland ice sheet (GIS) (Shepherd & Wingham 2007).

2 While Greenland and Antarctica account water seems to be less commonly discussed. for the vast majority of the worlds ice, it is the However, it is this aspect that requires the great- smaller continental glaciers that are melting est attention from policy makers, not just in ad- faster. Approximately 60% of the ice being lost dressing global warming, but also in planning for each year comes from small glaciers as opposed the lack of water. It is unlikely that changes to the ice sheets (Meier et al. 2007). These made now to reduce greenhouse gas emissions smaller glaciers lack the thermal inertia of the ice will be able to prevent many of these glaciers sheets. from melting completely, so other plans must be made now on how to keep the populations in The Artic sea ice is in a decline, primarily these regions supplied with water in order to in its extent during the summer months. Since avoid a humanitarian crisis. around 1960, the extent of summer ice has been decreasing at about 4% per decade (Deser et al. A somewhat less severe, but still prob- 2000). While sea ice loss does not affect sea lematic effect of the loss of glaciers will be the level, it has important implications for animals collapse of local economies that depend upon that are adapted to living on the ice. glaciers for tourism and recreation. The effects may ripple through into the larger winter sports There has been a concern that the loss of industry as a whole as well. permafrost in peatlands will cause the peat to dry out and decompose in a warming climate, which The loss of sea ice is another poster would contribute to large releases of CO2. How- child for global climate change, particularly be- ever, Johansson et al. (2006) calculated a net cause of the wildlife associated it (Amos 2007; increase of 16% in the CO2 sink following thaw- Stuck 2007). Despite the negative implications ing in a peatland. Despite the reduction in CO2, for wildlife, the loss of sea ice is also viewed to it was estimated that the peatland would have a have some positive consequences such as open- net 47% greater radiative forcing on the atmos- ing up new areas for fishing, exploration for oil phere over a 100 year because of increased and gas, and new shipping routes (Stuck 2007). methane production. Another study by Turetsky However, the opening up of new water may lead et al. (2007), which looked at various stages of to further international conflict as countries de- thawing peatlands, found that the increase in bate who controls and has rights to these various methane production would decrease over time, areas. Since most of the benefits from these new such that the radiative forcing from the increase open areas of have economic consequences, they methane might offset gains from CO2 sequestra- are all the more likely to result in conflicts. tion for as much as 70 years, but eventually the peatland becomes a net radiative forcing sink. IMPLICATIONS FOR POLICYMAKERS The new evidence that thawing peat- The biggest implication for policymak- lands may help offset anthropogenic increases in ers is to address the potential water shortages radiative forcing is encouraging, but more re- that will occur as the glaciers recede and vanish, search is necessary because there have been so while water is still available. This may involve few studies experimentally looking at the ques- establishing some other water storage system, tion. With a changing climate it is unknown if enacting policies to enforce water use efficiency, the effects will be consistent everywhere. It is and limiting continued population growth in possible that in some areas, the warming may these areas. It will be much easier to set up a also coincide with less precipitation and thawing new system now and be prepared, than waiting peatlands may dry out and decompose in these until the water runs out. areas thus contributing to greenhouse gas emis- In regards to implications of the arctic sions. waters opening up, new international treaties should be created regarding its access and use to PERSPECTIVES IN THE MEDIA AND PUBLIC the areas to avoid future conflicts. POLICY The implications of all the changes in The loss of sea ice and glaciers has been glaciers and sea ice enforce the point that new a hot topic in the media for making the case of policies are required to curb the continued an- global warming. Pictures of glaciers now versus thropogenic contribution to global climate 50 years ago make for dramatic evidence of a change. Due to the visible nature of the losses of warming climate. However, the implications for ice, changes to the cryosphere has been a strong people who depend on some of those glaciers for MURPHY CRYOSPHERE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 arguing point for change, however the cause permafrost plateaus and was influenced by re- would be further helped by emphasizing the gional MAT. A few species, such as Picea negative impacts it may have on humans. mariana trees on frozen bogs and Sphagnum mosses in thawed bogs, sequestered a dispropor- WORKS CITED WITH ABSTRACTS tionate amount of peat; in addition, changes in American Meteorological Society. 2000. their abundance following thaw changed peat Glossary of Meteorology, 2nd Edition. accumulation. Pb-210-dated cores indicated that http://amsglossary.allenpress.com. peat accumulation doubles following thaw and that the accumulation rate is affected by histori- Amos, J. 2006. Arctic sea ice 'faces rapid cal changes in species during succession. Peat melt'. in. BBC News. accumulation in boreal peatlands following thaw was controlled by a complex mix of local vegeta- Barry, R. G. 2006. The status of research tion changes, regional climate, and history. on glaciers and global glacier recession: a review. These results suggest that northern ecosystems Progress in Physical Geography 30:285-306. may show responses more complex than large Abstract: Mountain glaciers are key indicators releases of carbon during transient warming. of climate change, although the climatic vari- ables involved differ regionally and temporally. Deser, C., J. E. Walsh, and M. S. Timlin. Nevertheless, there has been substantial glacier 2000. Arctic sea ice variability in the context of retreat since the Little Ice Age and this has ac- recent atmospheric circulation trends. Journal of celerated over the last two to three decades. Climate 13:617-633. Documenting these changes is hampered by the paucity of observational data. This review out- Abstract: Forty years (1958-97) of reanalysis lines the measurements that are available, new products and corresponding sea ice concentration techniques that incorporate remotely sensed data, data are used to document Arctic sea ice variabil- and major findings around the world. The focus ity and its association with surface air tempera- is on changes in glacier area, rather than esti- ture (SAT) and sea level pressure (SLP) mates of mass balance and volume changes that throughout the Northern Hemisphere extratropics. address the role of glacier melt in global sea- The dominant mode of winter (January-March) level rise. The glacier observations needed for sea ice variability exhibits out-of-phase fluctua- global climate monitoring are also outlined. tions between the western and eastern North At- lantic, together with a weaker dipole in the North Camill, P., J. A. Lynch, J. S. Clark, J. B. Pacific. The time series of this mode has a high Adams, and B. Jordan. 2001. Changes in bio- winter-to-winter autocorrelation (0.69) and is mass, aboveground net primary production, and dominated by decadal-scale variations and a peat accumulation following permafrost thaw in longer-term trend of diminishing ice cover east the boreal peatlands of Manitoba, Canada. Eco- of Greenland and increasing ice cover west of systems 4:461-478. Abstract: Permafrost Greenland. Associated with the dominant pattern thaw resulting from climate warming may dra- of winter sea ice variability are large-scale matically change the succession and carbon dy- changes in SAT and SLP that closely resemble namics of northern ecosystems. To examine the the North Atlantic oscillation. The associated joint effects of regional temperature and local SAT and surface sensible and latent heat flux species changes on peat accumulation following anomalies are largest over the portions of the thaw, we studied peat accumulation across a re- marginal sea ice zone in which the trends of ice gional gradient of mean annual temperature coverage have been greatest, although the well- (MAT). We measured aboveground net primary documented warming of the northern continental production (AGNPP) and decomposition over 2 regions is also apparent. The temporal and spa- years for major functional groups and used these tial relationships between the SLP and ice anom- data to calculate a simple index of net annual aly fields are consistent with the notion that at- aboveground peat accumulation. In addition, we mospheric circulation anomalies force the sea ice collected cores from six adjacent frozen and variations. However, there appears to be a local thawed bog sites to document peat accumulation response of the atmospheric circulation to the changes following thaw over the past 200 years. changing sea ice cover east of Greenland. Spe- Aboveground biomass and decomposition were cifically, cyclone frequencies have increased and more strongly controlled by local succession mean SLPs have decreased over the retracted ice than regional climate. AGNPP for some species margin in the Greenland Sea, and these changes differed between collapse scars and associated differ from those associated directly with the

4 MURPHY CRYOSPHERE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

North Atlantic oscillation. The dominant mode of the sea-level rise that is not to ocean warming, of sea ice variability in summer (July-September) and about 60% of the ice loss is from glaciers is more spatially uniform than that in winter. and ice caps rather than from two ice sheets. The Summer ice extent for the Arctic as a whole has contribution of these smaller glaciers has accel- exhibited a nearly monotonic decline (-4% dec- erated over the past decade, in part due to ade(-1)) during the past 40 yr. Summer sea ice marked thinning and retreat of marine- variations appear to be initiated by atmospheric terminating glaciers associated with a dynamic circulation anomalies over the high Arctic in late instability that is generally not considered in spring. Positive ice-albedo feedback may ac- mass-balance and climate modeling. This accel- count for the relatively long delay (2-3 months) eration of glacier melt may cause 0.1 to 0.25 between the time of atmospheric forcing and the meter of additional sea-level rise by 2100. maximum ice response, and it may have served Rignot, E., and R. H. Thomas. 2002. Mass to amplify the summer ice retreat. balance of polar ice sheets. Science 297:1502- Johansson, T., N. Malmer, P. M. Crill, T. 1506. Abstract: Recent advances in the de- Friborg, J. H. Akerman, M. Mastepanov, and T. termination of the mass balance of polar ice R. Christensen. 2006. Decadal vegetation sheets show that the Greenland Ice Sheet is los- changes in a northern peatland, greenhouse gas ing mass by near-coastal thinning, and that the fluxes and net radiative forcing. Global Change West Antarctic Ice Sheet, with thickening in the Biology 12:2352-2369. Abstract: Thawing west and thinning in the north, is probably thin- permafrost in the sub-Arctic has implications for ning overall. The mass imbalance of the East the physical stability and biological dynamics of Antarctic Ice Sheet is likely to be small, but even peatland ecosystems. This study provides an its sign cannot yet be determined. Large sectors analysis of how permafrost thawing and subse- of ice in southeast Greenland, the Amundsen Sea quent vegetation changes in a sub-Arctic Swed- Embayment of West Antarctica, and the Antarc- ish mire have changed the net exchange of tic Peninsula are changing quite rapidly as a re- greenhouse gases, carbon dioxide (CO2) and sult of processes not yet understood. CH4 over the past three decades. Images of the Shepherd, A., and D. Wingham. 2007. Re- mire (ca. 17 ha) and surroundings taken with cent sea-level contributions of the Antarctic and film sensitive in the visible and the near infrared Greenland ice sheets. Science 315:1529-1532. portion of the spectrum, [i.e. colour infrared Abstract: After a century of polar exploration, (CIR) aerial photographs from 1970 and 2000] the past decade of satellite measurements has were used. The results show that during this pe- painted an altogether new picture of how Earth's riod the area covered by hummock vegetation ice sheets are changing. As global temperatures decreased by more than 11% and became re- have risen, so have rates of snowfall, ice melting, placed by wet-growing plant communities. The and glacier flow. Although the balance between overall net uptake of C in the vegetation and the these opposing processes has varied considerably release of C by heterotrophic respiration might on a regional scale, data show that Antarctica have increased resulting in increases in both the and Greenland are each losing mass overall. Our growing season atmospheric CO2 sink function best estimate of their combined imbalance is with about 16% and the CH4 emissions with about 125 gigatons per year of ice, enough to 22%. Calculating the flux as CO2 equivalents raise sea level by 0.35 millimeters per year. This show that the mire in 2000 has a 47% greater is only a modest contribution to the present rate radiative forcing on the atmosphere using a 100- of sea-level rise of 3.0 millimeters per year. year time horizon. Northern peatlands in areas However, much of the loss from Antarctica and with thawing sporadic or discontinuous perma- Greenland is the result of the flow of ice to the frost are likely to act as larger greenhouse gas ocean from ice streams and glaciers, which has sources over the growing season today than a accelerated over the past decade. In both conti- few decades ago because of increased CH4 emis- nents, there are suspected triggers for the accel- sions. erated ice discharge-surface and ocean warming, Meier, M. F., M. B. Dyurgerov, U. K. Rick, respectively- and, over the course of the 21st S. O'Neel, W. T. Pfeffer, R. S. Anderson, S. P. century, these processes could rapidly counteract Anderson, and A. F. Glazovsky. 2007. Glaciers the snowfall gains predicted by present coupled dominate Eustatic sea-level rise in the 21st cen- climate models. tury. Science 317:1064-1067. Abstract: Ice loss to the sea currently accounts for virtually all

5 MURPHY CRYOSPHERE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

Struck, D. 2007. NOAA scientists say Arc- Climate Experiment) gravity fields to estimate tic ice is melting faster than expected. Pages A06 the linear trend in Greenland ice mass during in Washington Post. 2002-2004. We recover a decrease in total ice mass of 82 +/- 28 km(3) of ice per year, consis- Turetsky, M. R., R. K. Wieder, D. H. Vitt, tent with estimates from other techniques. Our R. J. Evans, and K. D. Scott. 2007. The disap- uncertainty estimate is dominated by the effects pearance of relict permafrost in boreal north of GRACE measurement errors and errors in our America: Effects on peatland carbon storage and post glacial rebound (PG) correction. The main fluxes. Global Change Biology 13:1922-1934. advantages of GRACE are that it is sensitive to Abstract: Boreal peatlands in Canada have har- the entire ice sheet, and that it provides mass bored relict permafrost since the Little Ice Age estimates with only minimal use of supporting due to the strong insulating properties of peat. physical assumptions or ancillary data. Ongoing climate change has triggered wide- spread degradation of localized permafrost in Velicogna, I., and J. Wahr. 2006. Meas- peatlands across continental Canada. Here, we urements of time-variable gravity show mass explore the influence of differing permafrost loss in Antarctica. Science 311:1754-1756. regimes (bogs with no surface permafrost, local- Abstract: Using measurements of time-variable ized permafrost features with surface permafrost, gravity from the Gravity Recovery and Climate and internal lawns representing areas of perma- Experiment satellites, we determined mass varia- frost degradation) on rates of peat accumulation tions of the Antarctic ice sheet during 2002-2005. at the southernmost limit of permafrost in conti- We found that the mass of the ice sheet de- nental Canada. Net organic matter accumulation creased significantly, at a rate of 152 +/- 80 cu- generally was greater in unfrozen bogs and inter- bic kilometers of ice per year, which is equiva- nal lawns than in the permafrost landforms, sug- lent to 0.4 +/- 0.2 millimeters of global sea-level gesting that surface permafrost inhibits peat ac- rise per year. Most of this mass loss came from cumulation and that degradation of surface per- the West Antarctic Ice Sheet. mafrost stimulates net carbon storage in peat- Zwally, H. J., M. B. Giovinetto, J. Li, H. G. lands. To determine whether differences in sub- Cornejo, M. A. Beckley, A. C. Brenner, J. L. strate quality across permafrost regimes control Saba, and D. H. Yi. 2005. Mass changes of the trace gas emissions to the atmosphere, we used a Greenland and Antarctic ice sheets and shelves reciprocal transplant study to experimentally and contributions to sea-level rise: 1992-2002. evaluate environmental versus substrate controls Journal of Glaciology 51:509-527. Abstract: on carbon emissions from bog, internal lawn, Changes in ice mass are estimated from elevation and permafrost peat. Emissions of CO2 were changes derived from 10.5 years (Greenland) and highest from peat incubated in the localized per- 9 years (Antarctica) of satellite radar altimetry mafrost feature, suggesting that slow organic data from the European Remote-sensing Satel- matter accumulation rates are due, at least in part, lites ERS-1 and -2. For the first time, the dH/dt to rapid decomposition in surface permafrost values are adjusted for changes in surface eleva- peat. Emissions of CH4 were greatest from peat tion resulting from temperature-driven variations incubated in the internal lawn, regardless of peat in the rate of firn compaction. The Greenland ice type. Localized permafrost features in peatlands sheet is thinning at the margins (-42 +/- 2 Gt a(-1) represent relict surface permafrost in disequilib- below the equilibrium-line altitude (ELA)) and rium with the current climate of boreal North growing inland (+53 +/- 2 Gt a(-1) above the America, and therefore are extremely sensitive to ELA) with a small overall mass gain (+11 +/- 3 ongoing and future climate change. Our results Gt a(-1); -0.03 mm a(-1) SLE (sea-level equiva- suggest that the loss of surface permafrost in lent)). The ice sheet in West Antarctica (WA) is peatlands increases net carbon storage as peat, losing mass (-47 +/- 4 Gt a(-1)) and the ice sheet though in terms of radiative forcing, increased in East Antarctica (EA) shows a small mass gain CH4 emissions to the atmosphere will partially (+16 +/- 11 Gt a(-1)) for a combined net change or even completely offset this enhanced peatland of -31 +/- 12 Gt a(-1) (+0.08 mm a(-1) SLE). carbon sink for at least 70 years following per- The contribution of the three ice sheets to sea mafrost degradation. level is +0.05 +/- 0.03 mm a(-1). The Antarctic Velicogna, I., and J. Wahr. 2005. ice shelves show corresponding mass changes of Greenland mass balance from GRACE. Geo- -95 +/- 11 Gt a(-1) in WA and +142 +/- 10 Gt a(- physical Research Letters 32. Abstract: We 1) in EA. Thinning at the margins of the use 22 monthly GRACE (Gravity Recovery and Greenland ice sheet and growth at higher eleva-

6 MURPHY CRYOSPHERE FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 tions is an expected response to increasing tem- peratures and precipitation in a warming climate. The marked thinnings in the Pine Island and Thwaites Glacier basins of WA and the Totten Glacier basin in EA are probably ice-dynamic responses to long-term climate change and per- haps past removal of their adjacent ice shelves. The ice growth in the southern Antarctic Penin- sula and parts of EA may be due to increasing precipitation during the last century.

7 atmospheric, ocean, and terrestrial models; Global Circulation Models coupled together to create a computer model representation of the earth’s climate (Houghton Anna Lumsden 2004). In the above quotation, the IPCC climate scientists have used GCMs to predict the effects EXECUTIVE SUMMARY of different Special Report on Emission Global circulation models are computer Scenarios 2 (SRES) to determine a range of model representations of the earth’s climate warming possibilities over the next two decades. system. They are used to estimate the impacts of In this paper I will briefly outline the anthropogenic influences on future climate, most composition of a climate model, review the commonly global mean temperatures. As these current scientific literature, the perspectives of models have become more sophisticated the GCMs in the media, and how climate model results they generate are subject to greater results are implemented by policy makers. The uncertainty because the number of parameters focus here will not be on the predictions that which are estimated has increased. Although climate models make, but the uncertainties there is agreement among models that global inherent in those predictions and how these are temperature will rise in the next three decades perceived by the public and policy makers, it at regardless of emission policies, the complexity all. of these models and the uncertainties inherent in 3 them have led to a generally apathetic view of The first climate model was a simulation climate models in the media, and equivocating of the circulation patterns of the atmosphere in on the part of some governments to commit to 1949 (Flannery 2005). Since then, GCMs have radical changes in policy to deal with the causes increased in complexity, and also model the of global warming. terrestrial and oceanic components of the climate system, and the interactions and feedbacks within and between these systems, and the INTRODUCTION atmosphere. These interactions and feedbacks “Model experiments show that are modeled based on what scientists know about even if all radiative forcing agents1 are the physical processes, such as the conservation held constant at year 2000 levels, a of energy, and parameters within the climate further warming trend would occur in system. Models can have hundreds of parameters the next two decades at a rate of about which could include: horizontal and vertical 0.1oC per decade, due mainly to the movement of air or water, the amount of slow response of the oceans. About incoming solar radiation or the concentration of a twice as much warming (0.2oC per certain atmospheric gas. To model these physical decade) would be expected if emissions processes and parameters, the atmosphere and are within the rage of the SRES the ocean are divided into three-dimensional scenarios. Best-estimate projections grids. In addition to correct parameterization of from models indicate that decadal- processes, the cloud-radiation, water vapor, average warming over each inhabited ocean-circulation, and ice-albedo feedbacks continent by 2030 is insensitive to the within the system must be modeled as well. choice among SRES scenarios and is very likely to be at least twice as large Decades of research and data accumulation as the corresponding model-estimated have evolved into three uses for GCMs. One, to natural variability during the 20th model past climatic change; second, to model the century” (IPCC 2007) current climate and weather patterns; and third, to model the future climate. The ability of a The predictions of warming made by the climate model to accurately depict past and Inter-governmental Panel on Climate Change current climate, to predict the effects of natural (IPCC) are based on global circulation models disasters on the system (e.g. a volcanic eruption), (GCMs). GCMs, which have their origins in and to accurately depict the physical processes weather forecasting, are a combination of

2 The SRES scenarios represent four different combinations 1 Radiative forcing is a measure of the influence that a of global population and economic growth, and energy types climatic factor, such as cloud cover, has on the balance of and consumption. incoming and outgoing energy. Positive forcing warms the 3 In this paper GCMs and climate model are used earth’s surface, and negative forcing cools it (IPCC 2007) interchangeably. LUMSDEN GLOBAL CIRCULATION MODELS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 within the climate system are an indication of its therefore they give a more representative idea of credibility (Flannery 2005, Houghton 2004). possible impacts and outcomes for the particular This in turn leads to greater confidence in the scenario being investigated (Murphy et al. 2004, predictions of GCMs. Dettinger 2005, Stainforth et al. 2005). Some authors have suggested that even the most Over time, as the processing power of sophisticated GCM will provide only limited computers has increased and uncertainties in knowledge on the possible impacts of warming, computer programming have reduced, the therefore only large ensembles of climate models uncertainty from the inclusion of real world should be used to determine a range of impacts parameters has increased, as the number of and estimate uncertainty (Murphy et al. 2004, parameters has increased. A good example of Dettinger 2005). this is the recent inclusion of seal level pressure into model parameters (Flannery 2005). These Work by Stainforth et al. (2005), which uncertainties arise because each parameter is used the novel approach of running over 2000 estimated and averaged for each grid cell, and different simulations using the downtime on are dependent upon the particulars of the GCM personal computers, aimed to estimate used. This means that each climate model will uncertainty by changing groups of parameters in produce different outputs for combinations of the GCMs. Each of these parameter groups parameters. As GCMs are used mainly to created an ensemble, which were then combined forecast how anthropogenic effects on the to create a grand ensemble to estimate model climate system will lead to atmospheric warming, sensitivity, or the response of global mean the range in possible outputs which can be temperature to doubled levels of atmospheric produced has lead to debate in the scientific CO2 (Stainforth et al. 2005). The conclusions of literature and within the media and public as to the work were that this grand ensemble produced which results are important. a wide range of sensitivities, with uncertainty increasing with the number of parameters STATE OF THE SCIENCE perturbed (Stianforth et al. 2005). Uncertainty arises from at least four This work determined that extreme sources. One, is that the range of parameters sensitivity values cannot be ignored because they which are used for each model are different; two, are indicators of model shortcomings, and the choice of emission scenario; three, structural therefore where research resources should be uncertainty, where models do not necessarily allocatedm in order to improve parameter values depict climate processes accurately e.g. (Stainforth et al. 2005). A study by Zhang et al. feedbacks or non-linear change; and four, (2007) focusing on the difference between inherent climate variability (Zwiers 2002; modeled estimates versus observed changes in Dettinger 2005, Stainforth et al. 2005). The precipitation indicated that ensemble simulations uncertainties inherent in the generation of tended to underestimate regional precipitation climate models are evident in the trend of recent changes, and with wide ranges in uncertainties scientific publications, which have focused on which varied with latitude. These results suggest how to quantify these model uncertainties, and that more research resources need to be allocated relative importance of the range of predictions towards fine tuning model parameters. produced. Acknowledging the variability in results PERSPECTIVES IN THE MEDIA AND PUBLIC which occur due to using different climate POLICY models, the consensus of the scientific It is clear that GCMs are the main community has been to run a number of information source for planners about future simulations on different models, by perturbing warming trends; therefore their relative model parameters, and then comparing the forecasting abilities are important to the climate results. These ensembles 4 produce a range of change debate (Murphy et al 2004). However, responses for a number of different models, the science behind GCMs is so complex that I would venture to say that the lay person would 4 “An ensemble is a collection of predictions; each prediction not be able to interpret the statistical analyses is different from the others due to some prescribed change in that go into determining not only what are the the model condition, such as model: constructions, initial important parameters driving temperature conditions or future emissions of greenhouse gasses into the increases, but also the range of temperatures, global atmosphere” (Dettinger 2005)

2 LUMSDEN GLOBAL CIRCULATION MODELS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 sensitivities and uncertainties produced. It is 2050. Therefore if all emissions of greenhouse therefore up to climate scientists to interpret gases were to cease now, it would take until these values for the public, and policy makers. 2050 for the climate to stabilize (Zwiers 2002, Flannery 2005). One problem is that warming is A good example of scientific interpretation often predicted to the 2100’s; this is far beyond for the media and public are the IPCC the range of typical policy development and Assessment Reports. These reports are readily possible mitigation strategies (Zwiers 2002). available, and are geared towards guiding policy Although these temporal ranges are useful for makers in the decisions they have to make about looking at the differences in predictions between country s’ climate change and energy usage models, it tends to obscure the general agreement policies. The IPCC reports tend to remove the about the certain warming of the next few technical details and focus on the trends which decades (Zwiers 2002). the climate models display. The IPCC references the climate models which generate their results Globally, many countries ratified the Kyoto in a fairly cursory manner (see opening quote), Protocol in 2005, with the exception of the US without going into detail about the science and Australia. This law was to bind the 146 behind the GCMs used. countries that signed to cut their combined emissions to 5% below 1990 levels by 2008 to Similarly the complexity of the issue does 2012 (bbc.oc.uk. 2005) In the United States in not lend itself to discussion in the popular media. July 2007, President Bush put forward a “post- For example US Today, the most widely read Kyoto framework on energy security and climate newspaper in the US, has a readership of 5.4 change by 2008” (state.gov 2007). This million, 2.5 print (Marketwatch.com, 2007). A framework is designed to implement near term search on their website of keywords “climate domestic policies to reduce green house gas models” returned 59 search results from 1987 to emissions by 18% by 2012. This would include the present, 32 of which occurred since programs such as Energy Star, domestic methane December 20th 2005 (usatoday.com 2007). programs, and increasing the fuel economy of Compare these results with a search of “Paris vehicles by using alternative and renewable fuels. Hilton” for the same time period and 305 results These domestic policies are in addition to the are returned. This, I believe is an indication of a billions of dollars in research and design which combination of possibilities. Either, that the have been invested into reducing green house scientific community has not expressed the gases. importance of climate models to the public, therefore enabling an apathetic attitude; or the Despite this seeming commitment to topic is simply too complex for reporters to addressing climate change, in response to the interpret and engage with the public; or the IPCC’s final assessment report issued on media is responding to a low desire by the public November 17th 2007, the NY Times had this to engage with the issue. analysis of the administration’s response: According to a BBC.com poll (September “Despite the report’s added 2007), 80% of the public believes that climate emphasis on a list of “reasons for change is as the result of anthropogenic forcing. concern” about the continuing growth If this is the common public opinion, then of long-lived emissions that trap heat, perhaps it is not necessary to have a discourse senior White House officials said about GCMs in the public sphere. What may be Friday and Saturday that it remained more important is that the trends which have impossible to define a “dangerous” been observed in these data and agreed upon by threshold in the concentration of the scientific community are translated into greenhouse gases or resulting public policy. warming.” (NY Times 2007) Although it is probably not necessary to CONSIDERATIONS FOR POLICY MAKERS define “dangerous threshold in the concentration Despite the uncertainties inherent in climate of greenhouse gases or resulting warming”, some science, all GCMs agree that warming will might say that the uncertainty inherent in GCMs continue, and for the range of the next 20 to 30 has been used to equivocate about a serious years. Climate models agree on the amplitude of commitment to the implementation of drastic change, because the effects of this CO2 which is policy changes to reduce the concentrations of already in the atmosphere will not be felt until greenhouse gases expelled into the atmosphere.

3 LUMSDEN GLOBAL CIRCULATION MODELS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

In short, U.S. policy makers seem yet to be Flannery, T. 2005. The weather makers: convinced that although there are a range of how man is changing the climate and what it possibilities in results from GCMs, the means for life on earth. Atlantic Monthly Press agreement in the scientific community and the New York, NY public is that climate warming is not uncertain, Houghton, John. 2004. Global warming the and that policy needs to be implemented to complete briefing. Cambridge University Press. curtail its effects. 3rd Edition. REFERENCES IPCC Summary for Policy Makers. 2007. Bbc.co.uk. Man causing climate change. In Climate Change 2007: The physical science September 25, 2005. basis. Contribution of Working Group I to the http://search.bbc.co.uk/cgibin/search/results.pl?q Fourth Assessment Report of the =climate+change+poll&go.x=0&go.y=0&go=go Intergovernmental Panel on Climate Change &edition=i. Accessed November 19th 2007. Solomon, S., Qin, D., Manning M., Chen, Z., Marquis, M., Avery, K.B., Tignor, M., Miller, Bbc.co.uk. Q&A the Kyoto protocol. 16 H.L. (eds.). Cambridge University Press, February 2005. Cambridge, United Kingdom and New York, NY, http://news.bbc.co.uk/2/hi/science/nature/426992 USA. 1.stm Accessed November 19th 2007. Marketwatch.com November 15, 2007. Dettinger, M.D. 2005. From climate- USA TODAY remains the most widely read change spaghetti to climate-change distributions newspaper in the United States. for 21st century California. San Francisco http://www.marketwatch.com/news/story/usa- Estuary and Watershed Science 3 (1) Article 4, 1 today-remains-most- – 14 widely/story.aspx?guid=%7B52FE1518-B2D8- 4AD4-BBCF-FAC3A73EA43B%7D Accessed The uncertainties associated with climate- th change projections for California are unlikely to November 19 2007 disappear any time soon, and yet important long- Murphy, J.M., Sexton, D.H.M., Barnett, term decisions will be needed to accommodate D.N., Jones, G.S., Webb, M.J., Collins, M., those potential changes. Projection uncertainties Stainforth, D.A. 2004. Quantification of have typically been addressed by analysis of a modeling uncertainties in a large ensemble of few scenarios, chosen based on availability or to climate change simulations. Nature 430, 768 – capture the extreme cases among available 772 projections. However, by focusing on more common projections rather than the most Abstract: Comprehensive global climate extreme projections (using a new resampling models1 are the only tools that account for the method), new insights into current projections complex set of processes which will determine emerge: (1) uncertainties associated with future future climate change at both a global and greenhouse-gas emissions are comparable with regional level. Planners are typically faced with a the differences among climate models, so that wide range of predicted changes from different neither source of uncertainties should be models of unknown relative quality2,3, owing to neglected or underrepresented; (2) twenty-first large but unquantified uncertainties in the century temperature projections spread more, modelling process4. Here we report a systematic overall, than do precipitation scenarios; (3) attempt to determine the range of climate projections of extremely wet futures for changes consistent with these uncertainties, California are true outliers among current based on a 53-member ensemble of model projections; and (4) current projections that are versions constructed by varying model warmest tend, overall, to yield a moderately drier parameters. We estimate a probability density California, while the cooler projections yield a function for the sensitivity of climate to a somewhat wetter future. The resampling doubling of atmospheric carbon dioxide levels, approach applied in this paper also provides a and obtain a 5–95 per cent probability range of natural opportunity to objectively incorporate 2.4–5.4 8C. Our probability density function is measures of model skill and the likelihoods of constrained by objective estimates of the relative various emission scenarios into future reliability of different model versions, the choice assessments. of model parameters that are varied and their uncertainty ranges, specified on the basis of

4 LUMSDEN GLOBAL CIRCULATION MODELS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 expert advice. Our ensemble produces a range of Human influence on climate has been regional changes much wider than indicated by detected in surface air temperature1–5, sea level traditional methods based on scaling the pressure6, free atmospheric temperature7, response patterns of an individual simulation5,6 tropopause height8 and ocean heat content9. Human-induced changes have not, however, Stainforth, D. A., Aina, T., Christensen, C., previously been detected in precipitation at the Collins, M., Faull, N., Frame, D. J., global scale10–12, partly because changes in Kettleborough, J. A., Knight, S., Martin, A., precipitation in different regions cancel each Murphy, J. M, Piani, C., Sexton, D., Smith, L. A., other out and thereby reduce the strength of the Spicer, R. A., Thorpe, A. J., Allen, M. R. 2005. global average signal13–19. Models suggest that Uncertainty in predictions of the climate anthropogenic forcing should have caused a response to rising levels of greenhouse gases. small increase in global mean precipitation and a Nature 433, 403 – 406 latitudinal redistribution of precipitation, The range of possibilities for future climate increasing precipitation at high latitudes, evolution1–3 needs to be taken into account decreasing precipitation at sub-tropical when planning climate change mitigation and latitudes15,18,19, and possibly changing the adaptation strategies. This requires ensembles of distribution of precipitation within the tropics by multidecadal simulations to assess both chaotic shifting the position of the Intertropical climate variability and model response Convergence Zone20. Here we compare uncertainty4–9. Statistical estimates of model observed changes in land precipitation during the response uncertainty, based on observations of twentieth century averaged over latitudinal bands recent climate change10–13, admit climate with changes simulated by fourteen climate sensitivities—defined as the equilibrium models. We show that anthropogenic forcing has response of global mean temperature to doubling had a detectable influence on observed changes levels of atmospheric carbon dioxide— in average precipitation within latitudinal bands, substantially greater than 5K. But such strong and that these changes cannot be explained by responses are not used in ranges for future internal climate variability or natural forcing. We climate change14 because they have not been estimate that anthropogenic forcing contributed seen in general circulation models. Here we significantly to observed increases in present results from the ‘climateprediction.net’ precipitation in the Northern Hemisphere mid- experiment, the first multi-thousand-member latitudes, drying in the Northern Hemisphere grand ensemble of simulations using a general subtropics and tropics, and moistening in the circulation model and thereby explicitly Southern Hemisphere subtropics and deep resolving regional details15–21. We find model tropics. The observed changes, which are larger versions as realistic as other state-of-the-art than estimated from model simulations, may climate models but with climate sensitivities have already had significant effects on ranging from less than 2K to more than 11 K. ecosystems, agriculture and human health in Models with such extreme sensitivities are regions that are sensitive to changes in critical for the study of the full range of possible precipitation, such as the Sahel. responses of the climate system to rising Zwiers, Francis W. 2002. The 20-year greenhouse gas levels, and for assessing the risks forecast. Nature 416, 690 – 691 associated with specific targets for stabilizing these levels. Policy-makers need short-term climate predictions to develop strategies for coping with U.S. Department of State 2007. USA: climate change over the typical two-decade Energy needs, clean development and climate planning horizon. Two new studies increase our change. confidence in these predictions. http://www.state.gov/documents/organization/90 174.pdf. Accessed November 19th 2007 Zhang, X., Zwiers, F.W., Gegerl, G.C., Lambert, F.H., Gillett, N.P., Solomon, S., Stott, P.A., Nozawa, T. 2007. Detection of human influence on twentieth-century precipitation trends. Nature 448, 461 – 465

5 able development and adversely affect human Impact on freshwater resources rights. Nidhi Pasi STATE OF THE SCIENCE EXECUTIVE SUMMARY Flannery (2006) mentions that for every degree increase in global temperature, the world Water is indispensable to all life and to experiences one percent increase in rainfall. human activities. The impacts of the climate However, this increase is not evenly distributed change on freshwater resources are mainly due to in time and space leading to unusual patterns. observed increases in temperature (land and sea World rainfall in increasing over large parts and surface), sea level and precipitation variability. more rain is falling at high altitudes in winter These impacts will be compounded by factors leading to disastrous consequences. Also in- like population growth and current management creases in winter rains in the southern part of the practices. A significant percentage of population hemisphere is affecting agriculture and increas- already exists in water stress regions. The adap- ing extreme weather events (like flooding, ava- tive practices, management and planning will lanches etc.). At the same time certain regions determine the impacts of global warming on are being tipped into a perpetual rain deficit po- freshwater resources and their sustainable use/ tentially developing new Saharas. He talks about development. the evidence of the shift to a newer drier climate in Africa’s Sahel region, where models have INTRODUCTION: showed that rising sea temperature over the In- Water is indispensable to all forms of life dian Ocean due to accumulation of greenhouse and is needed for almost all human activities. gases resulted in rainfall decline. Historically, civilizations have flourished along or around the sources of water. Rivers have sup- Arnell (2004) further talks about the rela- ported life and have been a source of communi- tive effects of climate change and population cation. History is replete with examples of civili- growth on the future global water resources zations that have withered and vanished when stresses using the special report on emission sce- water became scarce. The global freshwater narios (SRES). The author estimates population availability is finite. However, with pressure of at risk by determining annual runoff (surplus/ ever increasing human population, demand for deficit) using a macro-scale hydrological model, direct human consumption, for food production monthly precipitation data downscaled to water- and consequent development and industrial proc- shed and population estimates. It has been esti- esses on water resources are ever increasing. The mated that in absence of climate change the UN Comprehensive Assessment of freshwater number of people living in water stressed regions resources estimated that about one third of the will depend upon the population scenarios and world’s population withdrawing more than 20% about 40% of world population in 2025 will be of the their available water resources are deemed water stressed. However, with climate change, to be suffering with water stress (Kundzewicz, decreased runoff increases water stress in some Z.W et all 2007). Moreover, it has been esti- parts of the world like Mediterranean, central mated that people living in conditions of acute and southern Africa, America and parts of water shortage will increase from present figure Europe. At the same time, increases in runoff in of 470 million to around 3000 million in 2025 wet seasons in certain parts of the world like (Vombatkere, Sudhir 2004) representing two- Southern and eastern Asia, may not be beneficial thirds of world population. Human activities as this leads to flood. The analysis also shows affect freshwater resources in terms of both qual- that the impacts of the changes (in terms of ity and quantity. Due to complex interconnec- population and emission scenarios) will also de- tions between climate and freshwater ecosystems, pend on how water resources are managed in the any change affects both mean states and variabil- future. ity. In addition, spatial variations in the distribu- tion of this prime natural resource have led to PERSPECTIVES IN THE MEDIA AND PUBLIC formation of “water surplus” and “water deficit” POLICY regions. Water scarcity leads to regional imbal- Climate change effects on freshwater sys- ances in terms of socio-economic development tems are often termed as the “other” water prob- and such imbalances are detrimental to sustain- lem in the media (Gertner, Jin 2007) because PASI FRESHWATER RESOURCES FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 global warming has been more commonly linked et all 2006) and long term potential sustainable with rise in the sea level and submergence of the development of freshwater resources.. coastal cities. However, steady melts of the mountain snow packs and the loss of the deep REFERENCES accumulated high latitude snow is a reality which 1) Flannery, Tim (2005). Liquid Gold: may just lead to lead to many challenges and changes in rainfall. Chapter 13: The uncertainties. weather makers: how man is changing the The working group II third assessment re- climate and what it means for life on earth. port summarizes apparent trends (both increase Atlantic Monthly Press : New York and decrease) in stream water volume, with peak flows likely to move to winter from spring due to 2) NOAA- GDLF (2007). National Oceanic early snowmelt. The glacier retreat will continue. and Atmospheric Administration - Moreover the magnitude and frequency of floods Geophysical Fluid Dynamics Laboratory is likely to increase and at the same time vol- Climate modeling research highlights. Will umes of low flows will decrease in many regions the wet get wetter and the dry drier? Vol 1, (NOAA- GDLF 2007). No.5, February 2007. http://www.gfdl.noaa.gov/research/climate/ The water quality degradation is likely to high- be degraded due to high temperatures. With the lights/PDF/GFDLhighlight_Vol1N5.pdf higher temperatures, increased intensity of pre- cipitation and shifts in time of peak flow will 3) Kundzewicz, Z.W., L.J. Mata, N.W. Arnell, further worsen many forms of water pollution. P. Döll, P. Kabat, B. Jiménez, K.A. Miller, The pollutants may include sediments, nutrients, T. Oki, Z. Sen and I.A. Shiklomanov dissolved organics, pathogens, pesticides, salt (2007). Freshwater resources and their and thermal pollution. This will impact the eco- management. Climate Change 2007: Im- systems, human health and operation costs of pacts, Adaptation and Vulnerability. Con- current water treatment and infrastructure sys- tribution of Working Group II to the Fourth tems. Assessment Report of the Intergovernmen- tal Panel on Climate Change. M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der CONSIDERATIONS FOR POLICYMAKERS Linden and C.E. Hanson, Eds., Cambridge Many current rivers originate in the glacier University Press, Cambridge. regions (particularly in the Hindu Kush Hi- malalyan region and sustaining the highly popu- 4) Gertner, Jin. (2007) The future is drying up. lated countries of India and China) and are sus- New York Times. October 21 2007. tained by the summer season glacier melt. Global http://query.nytimes.com/gst/fullpage.html? warming will lead to glacier retreat with in- res=9C0CEFDA103CF932A15753C1A961 creased river flows (floods) in short terms and 9C8B63 gradual decline (water scarcity, stress and 5) Vombatkere, Sudhir (2004). Interlinking drought) in flow over the next decades. National Rivers: to link or not to link? In: The decision makers within the countries Patekar, Medha, River Linking: a Millen- need to realize that the current water manage- nium Folly?: Maharashtra, National Alli- ment practices are very likely going to be inade- ance of People’s Movement. quate to reduce the negative impacts of climate Arnell, Nigel W. (2004). Climate change change on water supply reliability, flood risk and 6) and global water resources: SRES emis- health concerns. There need to be a continuous sions and socio-economic scenarios. Global evolution of management systems, as the un- Economic Change. Vol.14:31-55 In 1995, managed ones are likely to be most vulnerable. nearly 1400 million people lived in water- The impacts will also depend upon a particular stressed watersheds (runoff less than freshwater system characteristic. The adverse 1000m3/capita/year), mostly in south west effects of climate on freshwater systems may be Asia, the Middle East and around the Medi- further increased by the intensity of other terranean. This paper describes an assess- stresses like population growth. Hence there is a ment of the relative effect of climate need to incorporate the climate change variabil- change and population growth on future ity into the water management and planning global and regional water resources stresses, which could help in better adaptation (Mall, R.K.

2 PASI FRESHWATER RESOURCES FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 using SRES socio-economic scenarios and line could lead to variations in the numbers climate projections made using six climate of people with an increase or decrease in models driven by SRES emissions scenar- stress of between 15% and 20%. The im- ios. River runoff was simulated at a spatial pact of these changes on actual water resolution of 0.5_0.5_ under current and fu- stresses will depend on how water re- ture climates using a macro-scale hydro- sources are managed in the future. logical model, and aggregated to the water- shed scale to estimate current and future 7) Mall, R.K., Akhilesh Gupta, Ranjeet Singh, water resource availability for 1300 water- R. S. Singh and L. S. Rathore (2006) Water sheds and small islands under the SRES resources and climate change: An Indian population projections. The A2 storyline perspective. Current Science, Vol. 90, No. has the largest population, followed by B2, 12: 1610- 1626 In recent times, several then A1 and B1 (which have the same studies around the globe show that climatic population). In the absence of climate change is likely to impact significantly change, the future population in water- upon freshwater resources availability. In stressed watersheds depends on population India, demand for water has already in- scenario and by 2025 ranges from 2.9 to 3.3 creased manifold over the years due to ur- billion people (36–40% of the world’s banization, agriculture expansion, increas- population). By 2055 5.6 billion people ing population, rapid industrialization and would live in water-stressed watersheds economic development. At present, under the A2 population future, and changes in cropping pattern and land-use ‘‘only’’ 3.4 billion under A1/B1. Climate pattern, over-exploitation of water storage change increases water resources stresses in and changes in irrigation and drainage are some parts of the world where runoff de- modifying the hydrological cycle in many creases, including around the Mediterra- climate regions and river basins of India. nean, in parts of Europe, central and south- An assessment of the availability of water ern America, and southern Africa. In other resources in the context of future national water-stressed parts of the world— particu- requirements and expected impacts of cli- larly in southern and eastern Asia—climate mate change and its variability is critical for change increases runoff, but this may not relevant national and regional long-term be very beneficial in practice because the development strategies and sustainable de- increases tend to come during the wet sea- velopment. This article examines the poten- son and the extra water may not be avail- tial for sustainable development of surface able during the dry season. The broad geo- water and groundwater resources within the graphic pattern of change is consistent be- constraints imposed by climate change and tween the six climate models, although future research needs in India.. there are differences of magnitude and di- rection of change in southern Asia. By the 2020s there is little clear difference in the magnitude of impact between population or emissions scenarios, but a large difference between different climate models: between 374 and 1661 million people are projected to experience an increase in water stress. By the 2050s there is still little difference between the emissions scenarios, but the different population assumptions have a clear effect. Under the A2 population be- tween 1092 and 2761 million people have an increase in stress; under the B2 popula- tion the range is 670–1538 million, respec- tively. The range in estimates is due to the slightly different patterns of change pro- jected by the different climate models. Sen- sitivity analysis showed that a 10% varia- tion in the population totals under a story-

3 in the composition of the atmosphere. Anthro- Carbon Sinks and Sequestration pogenic carbon compounds emitted to the at- mosphere have long been known to have delete- Ken Hubbard rious effects. Since the Industrial Revolution (circa 1700), the carbon cycle has been imbal- EXECUTIVE SUMMARY anced due to increasing anthropogenic carbon Quantification of carbon sources and sinks inputs to the atmosphere. Atmospheric CO2 is an essential part of determining long term an- concentrations have increased approximately thropogenic impacts to global climate change. 30% from a pre-industrial level of 280 parts per Carbon is continually emitted to the atmosphere million (ppm) to present day level of 370 ppm in the form of carbon dioxide (CO2) as a byprod- (Houghton, 2004). As CO2 accumulates in the uct of many processes such as combustion of atmosphere, the “Greenhouse Effect” is magni- fossil fuels, biomass burning and land use fied. Compounds in the atmosphere create a changes. Increased concentration of CO2 in the layer above the Earth that let light and heat en- atmosphere contributes to the “Greenhouse Ef- ergy pass through, but do not allow the infrared fect”. The use of terrestrial carbon sinks as a radiation (heat) escape as readily. means of sequestering atmospheric CO2 has been studied recently. Carbon can be removed from Terrestrial carbon sequestration can be de- the atmosphere by terrestrial vegetation, captured fined as capture of CO2 and long term storage and stored in geologic formations and captured out of the atmosphere. Atmospheric carbon can and transported for geologic storage. The uncer- be removed and pumped into geologic reservoirs, tainties surrounding these different forms of ter- transported via pipeline to further geologic stor- restrial carbon sequestration warrant further in- age if no local reservoirs are present or seques- vestigation. Experiments have been conducted tered in the biomass of terrestrial vegetation. in order to model plant response to increased Although these seem like viable options to miti- gate the ongoing carbon emission problem, each CO2 concentration. The length of time these reservoirs can store the carbon, the efficiency of of these mitigation measures are not without carbon capture and storage, saturation limits of potential limitations. the reservoirs and response to changes in cli- matic variables are all issues requiring further STATE OF THE SCIENCE research to determine the feasibility of terrestrial Recent patterns and mechanisms of carbon sequestration. exchange by terrestrial ecosystems INTRODUCTION This paper written by Schimel et al. was published in Nature in 2001 and attempts to Carbon compounds are a major con- quantify exchange of CO2 between the atmos- stituent of all living and non-living components phere and terrestrial and marine environments in of the Earth. All life forms on the planet are three different latitudinal zones. This study uses built around carbon based structures. In addition inverse model calculations to estimate carbon to living organisms, substantial amounts of car- flux, calculating sources and sinks of carbon bon are allocated to non-living things such as based on CO2 distribution in the atmosphere. rocks, sediments, oceans and dead and decaying Inverse modeling (the top down approach) is one organic matter. Carbon, in the form or carbon of two primary methods of estimating carbon dioxide (CO2), is emitted naturally to the atmos- fluxes between the atmosphere and terrestrial phere as a byproduct of aerobic respiration, fires, environments. The primary goals are to identify rotting of wood and decaying of other organic the mechanisms controlling atmosphere- matter in soils (Houghton, 2004). Carbon emit- terrestrial fluxes, analyze spatial patterns of car- ted to the atmosphere by natural means is offset bon fluxes and develop explanations for interan- by the process of photosynthesis, in which plants nual variability in flux estimates. uptake CO2 in the air and emit oxygen as a by- product. It has been thought that these natural The paper estimates net sinks in terrestrial processes of carbon cycling were quite stable and marine environments in the 1980’s and prior to human induce disturbances (Houghton, 1990’s. It is suggested that the major mecha- 2004). nisms contributing to the net carbon sink in ter- restrial environments is land use change (i.e. Since the dawn of industrialized times, hu- reforestation from former agricultural lands) in man activities have caused measurable changes North America and land use, land management HUBBARD CARBON FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

and increased forest growth due to CO2 fertiliza- This study is quite well designed in that tion and nitrogen deposition in Europe. The au- both methods used served as a check of sorts to thors suggest that the variability in carbon fluxes the other method. When both the land-based and between years is likely due to changes in cli- atmosphere-based estimates of carbon flux are in matic factors, indicating that there appears to be general agreement, this serves as verification of a net release of carbon to the atmosphere during the utility of the each approach. warm and dry years and a net uptake from the atmosphere during cooler years. The Not-So-Big U.S. Carbon Sink It seems that the authors could have ex- This paper written by Field and Fung was panded the scope of the paper slightly to include published in Science in 1999. The primary focus a comparison of land-based estimation to their of the paper is to review two methods of quanti- atmosphere-based estimates. This could give fying carbon sinks, the bottom up and the top some indication as to the validity of the estimates down approach. As discussed above, the bottom if both approaches yielded similar results. These up, or land-based approach includes inventory results address the objectives stated in the paper measurements of carbon and the top down, or quite well. The authors also included a section atmosphere-based approach inputs global CO2 of issues needed to be addressed for future re- data into atmospheric transport models. This search. The carbon cycle is quite a dynamic sys- paper is a synthesis of data used in previous tem, especially when human impacts are added work in order to analyze the two methods of car- into the equation. The need for more models bon flux estimation and to determine the major with increasing complexity speaks to the multi- drivers in terrestrial carbon sequestration. faceted nature of the field of global climate The authors state that changes in historical change. land use have emerged as major factors influenc- ing carbon sequestration in addition to factors Consistent Land- and Atmosphere-Based such as rising temperatures, increases in atmos- U.S. Carbon Sink Estimates pheric CO2 and nitrogen deposition. The authors This paper written by Pacala et al. was pub- state that latitudinal estimates are becoming in- lished in Science in 2001. The authors attempt creasingly more reliable for analyzing terrestrial to compare model results of atmosphere-land processes due to a global network of atmospheric carbon fluxes using two different approaches. monitoring stations. The goal of the study was to determine sources The overlying conclusion of the paper and sinks in the coterminous United States. The seems to be that changes in historical land use first method is the land-based approach (the bot- are quite important when attempting to quantify tom up method) in which the authors use data terrestrial carbon sources and sinks. They sug- from direct inventory measurements of carbon, gest that future research should focus as much on reconstructions of land use changes and ecosys- history of land use practices as on ecosystem tem models. The second method is the atmos- changes and atmospheric composition. However, phere-based approach (the top down method) in it does not seem that the authors put forth a very which global CO2 concentration data is input into exhaustive review of the bottom up and top atmospheric transport models. down approaches to estimating carbon sinks. The land-based estimates of atmosphere to The text is slightly difficult to comprehend and ground carbon flux (carbon sink) yielded a much could use more justification for their conclusions. smaller range of values than did the atmosphere- The synthesis paper is only based on nine based estimates. However, using seasonal inver- sources. The paper would be more useful if it sion monthly data, the two methods agreed quite were broken into sections addressing each of the well. These results are quite impressive, when approaches and then a section for comparison taking into account the extreme diversity in input between the two methods. data into the two modeling methods. Both the land-based and atmosphere-based estimates indi- PERSPECTIVES IN THE MEDIA AND PUBLIC cated a large net carbon sink in the United States. POLICY Their analysis also indicated a steady atmosphere Carbon sequestration has received much to ground carbon flux for the study period of publicity in the mainstream media as of late. It 1980-1994. becomes big news when a large oil company such as BP invests money in a technology to

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capture CO2 produced during combustion of coal Pacala, S.W. et al. (2001). Consistent at electricity generating plants. BP, for instance, Land- and Atmosphere-Based U.S. Carbon Sink has entered into an agreement with Powerspan to Estimates. Science, 292, 2316-2320. develop a cost effective technology to capture For the period 1980-89, we estimate a carbon CO from power plant emissions (Powerspan, 2 sink in the coterminous United States between 2007). 0.30 and 0.58 petagrams of carbon per year Similary, a large scale sequestration project (petagrams of carbon = 1015 grams of carbon). in Germany, funded by the European Union, is in The net carbon flux from the atmosphere to the the planning stages. The proposed design will land was higher, 0.37 to 0.71 petagrams of car- include a facility to inject CO2 into the ground to bon per year, because a net flux of 0.07 to 0.13 a depth of approximately 1880 meters. The ini- petagrams of carbon per year was exported by tial stages of this project include feasibility test- rivers and commerce and returned to the atmos- ing of the technology and monitoring to deter- phere elsewhere. These land-based estimates are mine the long term stability of the stored gas larger than those from previous studies (0.08 to with a goal of full implementation by 2020 0.35 petagrams of carbon per year) because of (AgReport, 2007). the inclusion of additional processes and revised estimates of some component fluxes. Although CONSIDERATIONS FOR POLICYMAKERS component estimates are uncertain, about one- Although the science behind quantifying half of the total is outside the forest sector. We carbon sources, sinks and means of sequestering also estimated the sink using atmospheric models and the atmospheric concentration of carbon atmospheric CO2 are continually improving, policymakers should not rely on carbon seques- dioxide (the tracer-transport inversion method). tration solely to address the effects of carbon The range of results from the atmosphere-based emissions on global climate change. Although inversions contains the land-based estimates. sequestration projects may help to mitigate ef- Atmosphere- and land-based estimates are thus fects of increased carbon emissions, the only consistent, within the large ranges of uncertainty method to properly address the problem is to for both methods. Atmosphere-based results for mandate decreases in emissions of carbon. 1980-89 are similar to those for 1985-89 and There are vast uncertainties concerning the effec- 1990-94, indicating a relatively stable U.S. sink tiveness of sequestration including but certainly throughout the period. not limited to: the efficiency of capture and Schimel, D.S. et al. (2001). Recent pat- transport of CO2, long term stability of seques- terns and mechanisms of carbon exchange by tration projects such as geologic storage, satura- terrestrial ecosystems. Nature, 414, 169-172. tion limits of sinks and the unknown response of terrestrial environments to climate change. At- Knowledge of carbon exchange between the at- tempts to reduce carbon emissions by means mosphere, land and the oceans is important, such as “Carbon Credits” and international trea- given that the terrestrial and marine environ- ties like the Kyoto Protocol are steps in the right ments are currently absorbing about half of the direction. The next step will have to include carbon dioxide that is emitted by fossil-fuel incentives in order for developing nations to be combustion. This carbon uptake is therefore lim- able to work to reduce emissions without com- iting the extent of atmospheric and climatic promising economic and social well being. change, but its long-term nature remains uncer- tain. Here we provide an overview of the current state of knowledge of global and regional pat- CITED REFERENCES WITH ABSTRACTS terns of carbon exchange by terrestrial ecosys- Field, C.B. and Fung, I.Y (1999). The Not- tems. Atmospheric carbon dioxide and oxygen So-Big U.S. Carbon Sink. Science, 285, 544-545. data con®rm that the terrestrial biosphere was Atmospheric carbon emitted through human ac- largely neutral with respect to net carbon ex- tivities is stored in carbon sinks in oceans and change during the 1980s, but became a net car- terrestrial ecosystems. Two methods of quantify- bon sink in the 1990s. This recent sink can be ing the sinks are analyzed. largely attributed to northern extratropical areas, Houghton, J. (2004). Global Warming: The and is roughly split between North America and Complete Briefing, The greenhouse gases (pp. Eurasia. Tropical land areas, however, were ap- 28-42). New York, NY: Cambridge University proximately in balance with respect to carbon Press. exchange, implying a carbon sink that offset

3 HUBBARD CARBON FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 emissions due to tropical deforestation. The evo- lution of the terrestrial carbon sink is largely the result of changes in land use over time, such as regrowth on abandoned agricultural land and fire prevention, in addition to responses to environ- mental changes, such as longer growing seasons, and fertilization by carbon dioxide and nitrogen. Nevertheless, there remain considerable uncer- tainties as to the magnitude of the sink in differ- ent regions and the contribution of different processes. Powerspan Corp. “BP and Powerspan Col- laborate to Demonstrate and Commercialize CO2 Capture Technology for Power Plants” [Online] 19 November 2007. . AgReport. “Underground CO2 Storage Plant in Germany” [Online] 19 November 2007. .

4 that are necessary to fuel the storm moisture and The effects of climate change on postpone negative feedback (i.e., rising cold wa- coastal regions - with a focus on ter beneath the storm’s eye, see Willoughby 1999). Emanuel (2005) showed empirical evi- the US dence that tropical cyclone intensity (wind speed Juliette L. Smith and duration of storm) has significantly in- creased over the past thirty years, suggesting that EXECUTIVE SUMMARY if the predicted rise in sea surface temperature occurs (1 - 3°C over this century) so will coastal Coastal regions, including shorelines, storm intensity. Socioeconomic hardship is estuaries, wetlands, coastal margins, and coral likely to follow this alarming trend if landfall reefs, are vulnerable to climate change drivers occurs, as storm wind speed has been directly such as warming oceanic temperatures, sea-level correlated with the cost of a storm. Cyclone fre- rise, and precipitation fluctuations. These re- quency, however, is not as predictable, most gions house over ½ of the US population while likely due to other drivers of cyclones including providing valuable resources and services such vertical and horizontal windsheer and/or internal as aquaculture, freshwater aquifers, and storm dynamics of the storm itself. It is unknown how surge protection. climate change will affect windsheer and tropical storm formation. INTRODUCTION Emanuel (2005) suggested that an increase Climate change is predicted to act upon the in cyclone intensity may, in turn, lead to a speed- world’s coastal regions through three main ing-up of ocean circulation with more cold, forces: an increase in ocean temperature, sea- denser water being brought to the surface at the level rise, and changes in precipitation and river equator during a storm making it more easily flow (Scavia et al. 2002, and references therein). sunk when it reaches the poles. This suggestion These forces spin a web of direct and indirect is opposite that of the general scientific commu- effects on the weather, physical and biogeo- nity which hypothesizes that polar melting and chemical parameters, ecosystems, culture, and increased freshwater runoff will increase stratifi- socioeconomics of coastal regions, including cation and hinder vertical mixing, slowing down shorelines, estuaries, coral reefs, coastal wet- the conveyor belt. The Intergovernmental Panel lands, and ocean margins. Indirect, negative on Climate Change (IPCC) reports that it is very effects are also predicted for the larger continents likely that there will be a 25% reduction in circu- that rely on these fertile regions for numerous lation flow by the end of the century (Scavia et al. products and services. 2002). Either way, alteration to ocean circula- Increase in ocean temperature tion is likely to have vast impacts on the location and intensity of nutrient rich upwelling events, Warming ocean temperatures are expected global climate, and geographic distribution of to cause an increase in tropical cyclone strength coastal biota. and duration (i.e., hurricane, coastal storms), an increase in coral bleaching, and a northward shift Warmer ocean temperatures are also pre- in coastal region biota. More controversial pre- dicted to increase the frequency and geographic dictions include an increase in the frequency of distribution of coral bleaching events as these tropical cyclones, the shutdown or speeding up ecosystems already live near their upper thermal of ocean circulation, and the switch of estuaries tolerance limits. Warmer temperature periods to act as a nitrogen source instead of sink. The have been correlated with zooxanthellae (symbi- mean temperature of the upper 300 m of ocean otic algae) expulsion, slowing or halting of has increased by 0.31°C over the past 45 yr and growth or reproduction, or an increase in patho- warming has been recorded to depths as low as gen vulnerability. Other anthropogenic effects 3,000 m. The occurrence of widespread, deeper such as eutrophication, sedimentation, pollution, warmer waters has the potential to increase and coastline development will most likely hin- tropical cyclone strength and duration as (1) der the ecosystems ability to migrate or recolo- strength is dependent upon the difference in tem- nize at the same location. Similarly, estuarine, perature between the upper, colder troposphere wetland and shoreline biota will most likely have and the warmer, sea surface temperatures and (2) to migrate northwards or adapt when thermal storm duration is determined by the geographical tolerances are exceeded. range of warm surface and sub-surface waters SMITH COASTAL IMPACTS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

In the last two years, scientists have re- or less precipitation with climate change, they corded an alarming shift in US estuaries as these converge to state that there will be more extreme bodies of water have suddenly become a source, rainfall events, floods, and droughts (Scavia et al. instead of sink, for nitrogen (Lane 2007). Scien- 2002, and references therein). Precipitation run- tists argue that the switch is due to a community off supplies the coastal embayments with fresh- shift towards nitrogen-fixing bacteria or cyano- water, nutrients, and sediment. Without the de- bacteria as a result of oceanic warming; however, livery of sediment, the erosion of shoreline and the empirical data are sparce and rely on a com- loss of wetlands are to be expected; however, a parison of only four years: 1979, 1986, 2005, sudden influx of sediments, nutrients, or fresh- and 2006 (Fulweiler et al. 2007). If true, how- water (e.g., flooding or high rainfall event) can ever, this net influx of nitrogen into the system cause a wetland to be buried and the physical and may put the coastal ocean at risk for acidification biogeochemical status of the receiving water (i.e., nitrate is acidic) or the occurrence of harm- body to be altered. Alterations to freshwater ful algal blooms and fish/shellfish kills as am- input can also affect localized salinity levels in monia or nitrate levels rise. More research is the estuaries and wetlands, thereby indirectly needed to confirm this trend and determine the controlling the biotic community. For example, mechanism(s) behind the shift. a period of decreased runoff or drought would likely result in an increase in salinity, conditions Sea-level rise under which mangroves, a diverse nursery for Sea-level rise has been a continuous threat fish, mammals and invertebrates, would perish. to wetlands, shorelines, and human development over the last 100 years, rising at an average of 10 STATE OF THE SCIENCE – 20 cm. This threat has been bearable with ad- aptation, migration, or constructive barriers. Emanuel (2005): Over the next 100 years, however, sea level is In this modeling paper the author plots predicted to rise another 9 – 88 cm according to smoothed mean sea-surface temperatures (SST) the IPCC (Scavia et al. 2002). The final level of the Atlantic in September, the western North will be determined by the actual amount and Pacific from July – November, and the Atlantic duration of greenhouse gas emissions, rise in + western North Pacific, as an annual mean, atmospheric and oceanic temperatures, and the against storm intensity from 1950 – 2005. In all amount of glacial and ice cap melt. three cases, a significant positive relationship is derived, giving evidence for an increasing trend Coastal regions are very sensitive to a rise in cyclone intensity over the last 30 years. Storm in sea level (Scavia et al. 2002, and references intensity is described as an index of power dissi- therein). A rapid or substantial rise will likely pation (PDI), a measure based mostly on the prevent wetlands from accumulating peat or wind speed and duration of the storms that oc- sediment, and therefore, cause wetland submer- curred. sion or erosion. If migration inland is obstructed, then wetlands and shoreline will be lost. Human Willoughby (1999): development is also subjected to this threat, as This work provides an explanation on how over ½ of the US population already lives on the tropical cyclones are formed and sustained. 17% of land considered coastal and another 18 Tropical cyclones are created through the colli- million Americans are predicted to move to the sion and organization of already occurring thun- coast (i.e., CA, FL, TX, and WA). Shoreline derstorms that converged around a low-surface flooding, the inundation of freshwater aquifers, pressure zone. Overall, the storm relies upon the and the subsequent motility of toxic chemicals transfer of energy between the ocean surface and and water-borne pathogens are predicted to have the upper troposphere. As warm surface air large monetary implications, with a 50-cm sea- passes over the warm ocean, evaporation occurs. level rise estimated to cost between $20 and As the warm moist air mass rises in altitude the $200 billion by the end of this century. Protec- surrounding cooler temperatures and increased tion from storm surges will also decrease as wet- pressure of the troposphere causes condensation lands are lost to inundation. and cloud formation. Condensation releases heat Changes in precipitation and river flow which is mostly dissipated through precipitation. The cooled, dry air mass moves outward due to Although prediction models contradict in the coriolis effect and high pressure center at the regards to whether the US will experience more top of the storm, and consequently, sinks. As the

2 SMITH COASTAL IMPACTS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 air mass sinks it warms as a result of compres- freshwater inflow, ocean temperature and ice sion due the surrounding atmosphere, and is extent, and ocean circulation. Impacts are pre- again moved across the sea surface towards the dicted against the weather, organisms, ecosys- low pressure eye while accumulating water va- tems, culture, socioeconomics, and health of por. As the storm continues, more energy trans- coastal regions. ferred, resulting in greater winds, and more evaporation - the high and low pressure centers PERSPECTIVES IN THE MEDIA AND PUBLIC strengthen and even more energy is brought into POLICY the system. Lane (2007): Climate change affects tropical cy- clones because the ocean’s surface is warming at Disappointingly, this news feature in a greater rate than the upper troposphere making Nature did not provide a satisfactory synthesis of the temperature difference greater. The storm studies, and instead barraged the reader with intensifies because a greater differential equates numerous speculations and hypotheses in a man- to a greater power exchange between the water ner that was hard to follow or evaluate. The surface and upper troposphere through evapora- main points of the article were that (1) estuaries tion/condensation. Additionally, the warming of are switching from being a nitrogen sink to now the subsurface waters (3,000m) allows a storm to a nitrogen source and (2) that the switch is recent last longer as it then takes longer for colder and a result of global warming. No direct evi- warmers to upwell under the storm’s eye and dence was provided and the reader was forced to cause a negative feedback. read the original articles to gain an understanding of the arguments (see Fulweiler et al. 2007). And Fulweiler et al. (2007): worse, the reader is left feeling skeptical of global warming and the science behind its possi- In this research paper, sediment samples ble impacts. collected from Narragansett Bay, RI in 2006 switched to being a net source of nitrogen in- Kerr (2007): stead of a net sink. Four studies, consisting of different years, were compiled, showing a sud- Interestingly, this news focus article in Sci- den increase in nitrogen fixation in 2006 as com- ence began with an image of five devastated pared to 1979, 1986 and 2005 which instead Louisianans wading their way down a flooded were years with high rates of denitrification. The street with a caption that read “ungentle reminder. second point of the article was that phytoplank- Katrina's destruction brought global warming to ton biomass has decreased as a result of global mind.” Kerr points out that the public’s aware- warming. The data presented to support this ness of global warming is largely linked to “cli- theory was a scatter plot of years against mean mate science and weird weather:” Ice-melting of summer chlorophyll a concentrations. A trend of the Arctic, daffodil blooms in Washington, D.C decreasing chlorophyll a concentrations over in January, and most recently, the raging hurri- time occurred; however, sea surface or atmos- cane, Katrina. It was this last association that pheric temperatures were not plotted on the fig- drew my attention; Katrina being used as a ure. I felt this work was representative of a pre- poster child for global warming. Although I see liminary study instead of a conclusive work and the value in this association, I feel it may be a bit should be followed up with future annual meas- premature as the science is not sufficient to sup- urements. In addition, I think future studies port the claim. As discussed earlier, a positive, should include more spatial distribution across significant relationship exists between warming the estuary as different regions of the water body sea surface temperatures (SST) and tropical cy- are acting differently and sediments are inher- clone wind speed and duration (Emanuel 2005); ently patchy. however, not enough data yet exists to determine if there is also a relationship between SST and Scavia et al. (2002): the frequency of cyclone development or the landfall of storms. Based on current data, Scavia et al. (2002) provides a compre- Katrina was an example of poor land manage- hensive review of predicted climate change im- ment, but its direct connection to global warming pacts on US coastal and marine ecosystems and is still to be confirmed. possible adaptation and coping strategies. Major forces of climate change identified by the authors include changes to sea-level, coastal storms,

3 SMITH COASTAL IMPACTS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

CONSIDERATIONS FOR POLICYMAKERS Fulweiler, R.W., Nixon, S.W., Buckley, I am unaware of any US policy specifically B.A., Granger, S.L. 2007 Reversal of the net in place to protect coastal regions from possible dinitrogen gas flux in coastal marine sediments. future impacts associated with climate change, Nature 448; 180-182. such as dramatic sea-level rise, warming ocean The flux of nitrogen from land and atmosphere temperatures, or changes in precipitation or river to estuaries and the coastal ocean has increased runoff. Instead, policies exist to protect coastal substantially in recent decades. The observed regions from threats that have already been iden- increase in nitrogen loading is caused by popula- tified by governments. Such policies focus on tion growth, urbanization, expanding water and pollution and nutrient abatement, marine ecosys- sewer infrastructure, fossil fuel combustion and tem preserves, fishery closures, and wetland pro- synthetic fertilizer consumption. Most of the tection and mitigation. Additionally, local gov- nitrogen is removed by denitrification in the ernment has taken action to protect personal sediments of estuaries and the continental shelf, property against beach/shoreline erosion, coastal leading to a reduction in both cultural eutrophi- flooding, and storm surges; however, I believe cation and nitrogen pollution of the open ocean these regulations do not take into account the Nitrogen fixation, however, is thought to be a expected rise in sea level, local predictions for negligible process in sub-tidal heterotrophic ma- precipitation change, or increased ocean tem- rine systems. Here we report sediment core data peratures over the next few decades. Before new from Narragansett Bay, USA, which demonstrate policy can be made, global warming impacts that heterotrophic marine sediments can switch must be (1) further studied, independent, from from being a net sink to being a net source of other environmental threats (e.g., eutrophication, nitrogen. Mesocosm and core incubation ex- sedimentation, pollution, shoreline development, periments, together with a historic data set of hydrology alteration, etc.) and (2) studied in con- mean annual chlorophyll production support the junction with these threats to look for compensa- idea that a climate-induced decrease in primary tory, additive, or synergistic effects. production has led to a decrease in organic mat- ter deposition to the benthos and the observed CITED REFERENCES WITH ABSTRACTS reversal of the net sediment nitrogen flux. Our Emanuel, K. 2005 Increasing destructive- results suggest that some estuaries may no longer ness of tropical cyclones over the past 30 years. remove nitrogen from the water column. Instead, Nature 436; 686-688. nitrogen could be exported to the continental shelf and the open ocean and could shift the ef- Theory and modeling predict that hurricane in- fect of anthropogenic nitrogen loading beyond tensity should increase with increasing global the immediate coastal zone. mean temperatures, but work on the detection of trends in hurricane activity has focused mostly Kerr, R.A. 2007 U.S. Policy: A Permanent on their frequency and shows no trend. Here I Sea Change? Science 315 (5813); 756 – 757. define an index of the potential destructiveness Lane, N. 2007 Climate change: What's in of hurricanes based on the total dissipation of the rising tide? Nature 449; 778-780. power, integrated over the lifetime of the cyclone, and show that this index has increased markedly Scavia, D., Field, J.C., Boesch, F., Budde- since the mid-1970s. This trend is due to both meier, R.W., Burkett, V., Cayan, D., Fogarty, M., longer storm lifetimes and greater storm intensi- Harwells, M.A., Howarth, R.W., Mason, C., ties. I find that the record of net hurricane power Reed, D.J., Royer, T.C. Sallenger, A.H., Titus, dissipation is highly correlated with tropical sea J.G. 2002 Climate Change Impacts on U.S. surface temperature, reflecting well-documented Coastal and Marine Ecosystems. Estuaries 25 (2); climate signals, including multi-decadal oscilla- 149–164. tions in the North Atlantic and North Pacific, and Increases in concentrations of greenhouse gases global warming. My results suggest that future projected for the 21st century are expected to warming may lead to an upward trend in tropical lead to increased mean global air and ocean tem- cyclone destructive potential, and—taking into peratures. The National Assessment of Potential account an increasing coastal population—a sub- Consequences of Climate Variability and stantial increase in hurricane-related losses in the Change (NAST 2001) was based on a series of twenty-first century. regional and sector assessments. This paper is a summary of the coastal and marine resources

4 SMITH COASTAL IMPACTS FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 sector review of potential impacts on shorelines, estuaries, coastal wetlands, coral reefs, and ocean margin ecosystems. The assessment considered the impacts of several key drivers of climate change: sea level change; alterations in precipita- tion patterns and subsequent delivery of freshwa- ter, nutrients, and sediment; increased ocean temperature; alterations in circulation patterns; changes in frequency and intensity of coastal storms; and increased levels of atmospheric CO2. Increasing rates of sea-level rise and intensity and frequency of coastal storms and hurricanes over the next decades will increase threats to shorelines, wetlands, and coastal development. Estuarine productivity will change in response to alteration in the timing and amount of freshwater, nutrients, and sediment delivery. Higher water temperatures and changes in freshwater delivery will alter estuarine stratification, residence time, and eutrophication. Increased ocean temperatures are expected to increase coral bleaching and higher CO2 levels may reduce coral calcification, making it more difficult for corals to recover from other disturbances, and inhibiting poleward shifts. Ocean warming is expected to cause poleward shifts in the ranges of many other or- ganisms, including commercial species, and these shifts may have secondary effects on their predators and prey. Although these potential impacts of climate change and variability will vary from system to system, it is important to recognize that they will be superimposed upon, and in many cases intensify, other ecosystem stresses (pollution, harvesting, habitat destruc- tion, invasive species, land and resource use, extreme natural events), which may lead to more significant consequences. Willoughby, H.E. 1999 Hurricane heat en- gines. Nature 401; 649-650.

5 be manifested in species distributions and Climate Change Effects on biodiversity. Biodiversity and Species Ranges STATE OF THE SCIENCE Lisa Giencke In order to understand how scientists make predictions about the future range of a given EXECUTIVE SUMMARY species, we should first examine the models Climate envelope modeling is one of the behind the science. One of the key ways of key methods that scientists have been utilizing in predicting such changes is through the use of order to predict how future climate change will bioclimate envelope models. The article by affect species ranges. However, there has been Pearson and Dawson (2003) provides an some dispute within the scientific community as informative overview, and it also provides some to the accuracy and usefulness of these models. of the main criticisms (and counter-criticisms) in The main criticisms are that these models do not the design of these models. account for biotic interactions, genetic adaptation or dispersal. As our knowledge about these Two of the main approaches of bioclimate subjects improves, it will be increasingly envelope models are to either correlate current important to include them into species range species distributions with environmental models. For now, however, these bioclimate conditions or to examine physiological responses models, if environmental variables are used in of a given species to its environment. In either the appropriate context and if the inherent case, it is assumed that species will show the limitations of these models are presented in full, same response to the environment in the future are a means to investigate the magnitude of as they do today, and so climate change range changes. scenarios are used to simulate future distribution. Many studies have been conducted There are three major criticisms often throughout the world showing the changes that directed toward the bioclimate envelope have already occurred due to a moderately small approach, which are: it does not accurately take change (compared at least to what is possible in into account biotic interactions, evolution or the future) in global climate. One study shows genetic adaptation or dispersal ability. In each that on average, across a variety of taxonomic case, the authors provide either a counter- groups, range changes are approximately 6.1 km criticism or show how models could be or m poleward or upward in elevation per decade improved in the future with a better (Parmesan and Yohe 2003). Other studies take a understanding of the complexity of each issue. broader look at some of the ecological responses In answering the question posed by the that can be attributed to climate change. Still article (are bioclimate envelopes useful?), it is other studies look at extinction rates and predict clear that the authors would agree that they are. that somewhere between 15-37% of species will They conclude the article by providing a be “committed to extinction” by 2050, if the hierarchical framework within which future mid-range prediction in climate change and models should be designed. They assert that this emission standards are accurate (Thomas et al framework is not perfect and may be over 2004). simplistic, but that it at least provides some guidelines as to what environmental variables INTRODUCTION should be considered when modeling at various According to the Synthesis Report of scales. As with any predictions of the future, the Fourth Assessment Report of the there are inherent limitations to the accurate Intergovernmental Panel on Climate Change simulation of species ranges into the future. there has been an increase in global surface These are due in large part to our as-yet temperature of 0.74º C in the last 100 years. The imperfect understanding of the complexity of report goes on to say, “In terrestrial ecosystems, natural systems. The authors conclude that earlier timing of spring events and poleward and bioclimate envelopes models are a good first upward shifts in plant and animal ranges are with pass toward understanding the magnitude of the very high confidence linked to recent warming” changes to be expected. Even so, they stress the (IPCC 2007). Therefore, it is becoming importance knowing the limitations of these increasingly important that we investigate the models consequences of further climate change that will GIENCKE BIODIVERSITY FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

Many studies have been conducted already appears to have joined habitat loss, using bioclimate envelope models and other invasive species and overexploitation as a major methods to determine if there is already a driving force of population- and species-level detectable influence of climate change on species extinctions” (Thomas et al. 2006). ranges, biodiversity and extinction. One of these concluded, as they termed it, that a “globally PERSPECTIVES IN THE MEDIA AND PUBLIC coherent climate fingerprint” does indeed exist POLICY (Parmesan & Yohe 2003). Their research used a As part of a year-long effort in probabilistic model to determine how likely it is conjunction with National Geographic, National that climate is the major force behind observed Public Radio is producing a special series called range and phenological changes. The results “Climate Connections” with the objective to show that 74-91% of documented changes occur examine “how climate changes people and how in the direction expected based on climate people change climate.” One recent installment change predictions and that these changes (October 29, 2007) examined the effect that amount to a shift of 6.1 km toward the poles or climate is having on sugar maples in New m upward in elevation. England. The sugar maple is crucial for its Another study (Walther et al. 2002) production of syrup and is very sensitive to reviewed the various ecological changes that are changes in climate. Many maple syrup producers being in observed in various ecosystems, are having a hard time extracting the same spanning from species- to community-level quantity of sap from the trees that they have effects. The paper focuses on changes in gotten in the past. phenology, species ranges, invasive species, As the example above shows, the community composition and biotic interactions. species that are going to garner the most Changes have been observed in the spring timing attention as climate change continues to unfold of many biological activities including flowering, are the relatively few charismatic plant and bird migration and calling or singing in animal species that people know and pay amphibians and birds. Species ranges, as noted attention to. Changes in butterfly, wildflower and above, are moving poleward or upward in bird distributions or abundance will surely be accordance with climate changes. Species noticed before all the millions of more mundane invasions are expected to increase as non-native creatures, including insects, invertebrates and organisms are more likely to survive in regions bacteria, whose contribution to ecosystems may that were previously inhospitable. Community not yet be fully realized, and that may not ever composition is expected to change since climate be known to science before they become extinct. change will cause individual species to react in Even species of great scientific importance, such different ways. This has the potential to change as two species of gastric brooding frog that dynamics between trophic levels. Despite possessed a previously unknown method of lingering uncertainties, it is clear that climate is reproduction, are at risk – both frogs have ceased playing a role in each of the above cases. to be seen in the wild, one just months after it Other studies have focused on the risk was first discovered (Flannery 2005). of species extinctions. One study used a bioclimate envelope approach, and specifically CONSIDERATIONS FOR POLICYMAKERS took into account dispersal ability by using two Besides knowing how climate change is dispersal scenarios: one of no dispersal and one going to effect species ranges and extinction of high (universal) dispersal. The authors claim rates, it will be ever more important for that species will likely fall somewhere in- policymakers to consider the importance of the between these scenarios – that is, these two interplay between climate change and habitat scenarios form the upper and lower bounds of fragmentation. Even species with high dispersal likely extinction values. Looking only at abilities may have a hard time migrating through endemic species of various taxonomic groups the human-modified environment. One solution across the world, the study predicts that 15-37% to this problem might be the creation and of species will be “committed to extinction” by implementation of conservation corridors which 2050, given a mid-range climate change scenario would hopefully allow at least some species to (Thomas et al. 2004). A more recent study found migrate unimpeded by development. that “For ectothermic animals with relatively short generation times, at least, climate change

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Changes in ranges and extinctions of Pearson, R. G. & Dawson, T. P. Predicting charismatic organisms may spark some policy the impacts of climate change on the distribution initiatives limiting greenhouses gases, as the of species: are bioclimate envelope models policymakers and general public start to observe useful? Global Ecol. Biogeog. 12, 361–371 for themselves the consequences of climate (2003). change. Modelling strategies for predicting the potential impacts of climate change on the LITERATURE CITED natural distribution of species have often focused In New England, Concern Grows for Sugar on the characterization of a species' bioclimate Maple (Climate Connections). Ketzel Levine. envelope. A number of recent critiques have NPR, Washington, D.C. 29 Oct. 2007. questioned the validity of this approach by Summary for Policymakers of the Synthesis pointing to the many factors other than climate Report of the IPCC Fourth Assessment Report. that play an important part in determining Intergovernmental Panel on Climate Change. species distributions and the dynamics of 2007. distribution changes. Such factors include biotic interactions, evolutionary change and dispersal Flannery, Tim. The Weather Makers. Text ability. This paper reviews and evaluates Publishing Company: Melbourne, Australia. criticisms of bioclimate envelope models and 2005. discusses the implications of these criticisms for the different modelling strategies employed. It is Parmesan, C. & Yohe, G. A globally proposed that, although the complexity of the coherent fingerprint of climate change impacts natural system presents fundamental limits to across natural systems. Nature 421, 37–42 predictive modelling, the bioclimate envelope (2003). approach can provide a useful first Pearson, R. G. & Dawson, T. P. Predicting approximation as to the potentially dramatic the impacts of climate change on the distribution impact of climate change on biodiversity. of species: are bioclimate envelope models However, it is stressed that the spatial scale at useful? Global Ecol. Biogeog. 12, 361–371 which these models are applied is of fundamental (2003). importance, and that model results should not be interpreted without due consideration of the Thomas, C. D. et al., Extinction risk from limitations involved. A hierarchical modelling climate change. Nature 427, 145 (2004). framework is proposed through which some of Thomas, C.D., Franco, A.M.A. & Hill J.K. these limitations can be addressed within a Range retractions and extinction in the face of broader, scale-dependent context. climate warming. Trends Ecol.. Evol 21, 415-416 Parmesan, C. & Yohe, G. A globally (2006). coherent fingerprint of climate change impacts Walther, G.R., Post, E., Convey, P., Menze, across natural systems. Nature 421, 37–42 1, A., Parmesan, C., Beebee, T.J.C., Fromentin, (2003). J.M., Hoegh-Guldberg, O.&Bairlein, F. Causal attribution of recent biological Ecological responses to recent climate change. trends to climate change is complicated because Nature 416, 389–395 (2002). non-climatic influences dominate local, short- term biological changes. Any underlying signal ABSTRACTS FROM CITED REFERENCES from climate change is likely to be revealed by 1. Predicting the impacts of climate change analyses that seek systematic trends across on the distribution of species: are bioclimate diverse species and geographic regions; however, envelope models useful? debates within the Intergovernmental Panel on 2. A globally coherent fingerprint of Climate Change (IPCC) reveal several climate change impacts across natural systems. definitions of a 'systematic trend'. Here, we explore these differences, apply diverse analyses 3. Ecological responses to recent climate to more than 1,700 species, and show that recent change. biological trends match climate change predictions. Global meta-analyses documented 4. Extinction risk from climate change. significant range shifts averaging 6.1 km per decade towards the poles (or metres per decade

3 GIENCKE BIODIVERSITY FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 upward), and significant mean advancement of greenhouse gas emissions and strategies for spring events by 2.3 days per decade. We define carbon sequestration. a diagnostic fingerprint of temporal and spatial Thomas, C.D., Franco, A.M.A. & Hill J.K. 'sign-switching' responses uniquely predicted by Range retractions and extinction in the face of twentieth century climate trends. Among climate warming. Trends Ecol.. Evol 21, 415-416 appropriate long-term/large-scale/multi-species (2006). data sets, this diagnostic fingerprint was found for 279 species. This suite of analyses generates Until recently, published evidence for the 'very high confidence' (as laid down by the IPCC) responses of species to climate change had that climate change is already affecting living revealed more examples of species expanding systems. than retracting their distributions. However, recent papers on butterflies and frogs now show Walther, G.R., Post, E., Convey, P., Menze, that population-level and species-level 1, A., Parmesan, C., Beebee, T.J.C., Fromentin, extinctions are occurring. The relative lack of J.M., Hoegh-Guldberg, O.&Bairlein, F. previous information about range retractions and Ecological responses to recent climate change. extinctions appears to stem, at least partly, from Nature 416, 389–395 (2002). a failure to survey the distributions of species at There is now ample evidence of the sufficiently fine resolution to detect declines, and ecological impacts of recent climate change, from a failure to attribute such declines to from polar terrestrial to tropical marine climate change. The new evidence suggests that environments. The responses of both flora and climate-driven extinctions and range retractions fauna span an array of ecosystems and are already widespread. organizational hierarchies, from the species to the community levels. Despite continued uncertainty as to community and ecosystem trajectories under global change, our review exposes a coherent pattern of ecological change across systems. Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible. C. D. Thomas et al., Extinction risk from Climate Change. Nature 427, 145 (2004). Climate change over the past ~30 years has produced numerous shifts in the distributions and abundances of species1,2 and has been implicated in one species-level extinction3. Using projections of species’ distributions for future climate scenarios, we assess extinction risks for sample regions that cover some 20% of the Earth’s terrestrial surface. Exploring three approaches in which the estimated probability of extinction shows a powerlaw relationship with geographical range size, we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15–37% of species in our sample of regions and taxa will be ‘committed to extinction’. When the average of the three methods and two dispersal scenarios is taken, minimal climate-warming scenarios produce lower projections of species committed to extinction (~18%) than mid-range (~24%) and maximum change (~35%) scenarios. These estimates show the importance of rapid implementation of technologies to decrease

4 necessary that policymakers use phenology data The Effect of Climate Change on as strong evidence that global warming is a Species’ Phenology serious threat and impetus to take action.

Laura Heath INTRODUCTION Phenology is defined in biology as the EXECUTIVE SUMMARY timing of life history events. Such events Phenology is the timing of development include breeding, migration, hibernation, from one point in an organism’s life cycle to metamorphosis, leaf out, bud burst, flowering another. Phenological events can include timing and leaf senescence, amongst others. It has been of flowering, leaf out, migration, and well documented that many life history events reproduction, amongst others. Due to the vary from year to year based on climate dependence of many phenological events on conditions, and as a result, it is thought that temperature, species’ phenology is thought to be phenology will be one of the earliest and most one of the easiest ways to document the easily recognizable traits that change in response occurrence of global climate change. In addition, to global climate change. In addition, phenology changes in species’ phenologies have the is a subject easily identifiable with the general potential to impact ecological processes, public, as the public’s connection to the natural agriculture, forestry, economics and human world is often associated with elements such as health. flowering time, bird migration and leaves Current scientific research indicates that changing color. many geographic areas within the mid-latitudes Changes in plant phenology have the of the northern hemisphere have shown increases potential to have many ecological, social and in the onset of spring and delays in the onset of economic impacts. Agricultural and forestry fall. Research has determined that globally, and industries can be affected by changes in plant across multiple trophic levels, phenologies are productivity, length of growing season and occurring an average of 2.3 days earlier per zoning that can ultimately result from changes in decade (Parmesan and Yohe 2003). Research plant phenology. Changes in phenology can also has documented earlier onset of tree bud burst alter ecological systems by altering interspecific (Badeck et al. 2004), plant flowering (Fitter and competition, disrupting highly coupled Fitter 2002), frog calling (Gibbs and Breisch associations amongst organisms at different 2001), bird migration (Cotton 2003) and bird trophic levels and altering the terrestrial carbon egg-laying (Dunn and Winkler 1999). Although balance. Finally, changes in plant phenology can changes in species’ phenologies are not always impact human health, such as changes in the detrimental to ecosystem functioning, they can timing and abundance of pollen release, which be in situations where one organism is highly affects the seriousness and treatment of allergies. dependent on the timing of a life cycle event of This paper will explore the current knowledge on another organism. One such example is the the impacts of global climate change on species’ recent observation that cold winters and warm phenologies. springs are causing unequal rates of advancement of winter moth (Operophtera STATE OF THE SCIENCE brumata) egg hatching and English oak (Quercus Long-term phenological data has robur) bud burst, causing moths to hatch before historically been collected by amateur naturalists their food source (oak) has developed (Visser with a connection to the agricultural industry. and Holleman 2001). Today, many countries of Europe, North Change in species’ phenologies is a America and Asia have developed national subject easily understood by the public and phonological networks to aid in long-term data therefore used in the mass media as a way to collection and compilation. The phenology demonstrate the validity of global warming. network of the United States began in 2007 and Although earlier onset of spring and later onset aims to get citizens involved in phenology data of fall could be perceived as positive collection (such as bud burst, flowering time and consequences of global climate change, the first site of migratory birds) in order to build a media still recognizes these changes as abnormal, dataset that is as large as possible and which is essential in conveying the serious geographically extensive. The phenological nature of global climate change. It is therefore network of Britain currently has 50,000 citizens HEATH PHENOLOGY FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 submitting phenology data every year. In breeders, exhibited earlier first calling dates, up addition to “on the ground” data collected by to 13 days earlier, in the 1990’s as compared to citizens and scientists around the world, new the period from 1900 to 1912. In addition, technology has recently allowed for large-scale average daily temperatures increased over the data collection using satellite technology. The last century during 5 of the 8 months important Normalized Difference Vegetation Index (NDVI) for frog development, indicating that earlier first is a remote-sensing technique using NASA calling dates could be a biotic response to satellites that measure the amount of light increased temperatures. Changes in time of reflecting off the earth at varying wavelengths. reproduction have also been documented for tree This technology is based on the principle that swallows in North America. Dunn and Winkler green plants absorb visible light (at wavelengths (1999) found that tree swallows exhibited 0.4-0.7 µm) and reflect near infrared light (at advancement in egg-laying by an average of 9 wavelengths 0.7-1.1µm). As a result, days from 1959 to 1991. In addition, egg-laying measurements of visible and infrared light date was highly correlated to mean May air reflectance by the earth can serve as a way to temperatures. Finally, Cotton (2004) found that quantify how green the earth is over time, and birds in England migrate from sub-Saharan therefore how the onset of spring and fall is Africa an average of 8 days earlier than they did changing. 30 years ago. Many studies encompassing large Although changes in species’ geographical areas and habitat types now report phenologies due to global climate change will that plant and animal species’ phenologies are not always be detrimental to organisms, some changing as of late, which have been shown to highly specialized systems are threatened by be correlated to increasing temperatures. Fitter global warming. One such system is that of the and Fitter (2002) presented data, collected by a winter moth (Operophtera brumata) and English single observer, concerning the first flowering oak (Quercus robur). Winter moth egg hatching dates of 385 plant species in Britain from 1954 is timed to coincide with oak bud burst such that to 2000. The authors determined that the plants moth larvae can feed on young, easily digestible flowered an average of 4.5 days earlier in the oak leaves. Visser and Holleman (2001), using 1990’s than the previous decades. First descriptive modeling techniques, found that flowering date of plants blooming in February, between 1975 and 2000, there has been an March and April were correlated with increase in the mis-timing of moth egg hatching temperatures of the previous month (January, and oak bud burst. The authors attributed this February and March, respectively). In addition, result to recent increases in spring temperatures, annual plants exhibited earlier average flowering which cause advancement of both moth egg date in the 1990’s by 7.8 days than perennials, hatching and oak bud burst, but no subsequent with an average of 3.2 days earlier. Finally, changes in the number of winter frost days, insect-pollinated plants had an earlier first which delays oak development. Therefore, flowering date (by 4.8 days) than wind- warm springs and cold winters lead to egg pollinated plants (3.5 days earlier) and insect- hatching up to three weeks before bud burst, pollinated plants flowering in the spring which can result in large-scale mortality of appeared to be most sensitive to warming. The moths. This example of loss of synchrony across fact that spring-flowering, insect-pollinated trophic levels is particularly important because it plants flowered earlier in the 1990’s than all demonstrates that organisms highly dependent other plant types could have drastic on one another can become threatened by global consequences on those insect-plant systems, climate change. especially if synchrony of insect development and plant flowering is lost. The work discussed PERSPECTIVES IN THE MEDIA AND PUBLIC in this paper is particularly important not only POLICY because it has a long timeframe (1954-2000), but Change in species’ phenologies over time is also because it is the only phenology study that a subject that is easily understood by the general uses data collected by a single observer. public. Many media outlets, including Phenologies of animals have also been magazines and local newspapers, have used shown to be affected by global warming. Gibbs phenological data to demonstrate the validity of and Breisch (2001) found that many frogs of global warming. An article published in the central New York, especially early spring New York Times entitled “March may be

2 HEATH PHENOLOGY FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 coming in like a lamb” summarizes, in a simple Climate change effects on seasonal activity in but accurate way, current knowledge on terrestrial ecosystems are significant and well phenological changes that have been attributed to documented, especially in the middle and higher global warming (Stevens 1999). Although this latitudes. Temperature is a main driver of many article could easily spin the concept of earlier plant developmental processes, and in many spring onset as a positive consequence of global cases higher temperatures have been shown to climate change, it recognizes that these observed speed up plant development and lead to earlier changes are not consistent with historical trends. switching to the next ontogenetic stage. As a result, changes in phenology hold the Qualitatively consistent advancement of potential to be a poster child for the public to vegetation activity in spring has been demonstrate that global warming is indeed documented using three independent methods, occurring, as demonstrated by the assertion in based on ground observations, remote sensing, the article that “all the recent studies indicate that and analysis of the atmospheric CO2 signal. a warming and greening of the planet is indeed However, estimates of the trends for under way” (Stevens 1999). However, some advancement obtained using the same method media outlets, especially those without a strong differ substantially. We propose that a high base in science, generally focus on consequences fraction of this uncertainty is related to the time of phenology changes that have a direct impact frame analysed and changes in trends at decadal on peoples’ daily lives rather than broad time scales. Furthermore, the correlation between ecological functioning. Such topics include the estimates of the initiation of spring activity effects of climate change on gardening, winter derived from ground observations and remote and spring recreation, and the maple syrup sensing at interannual time scales is often weak. industry. Although the human aspect of the We propose that this is caused by qualitative problem is important, it gives an incomplete differences in the traits observed using the two perspective on the issue. methods, as well as the mixture of different ecosystems and species within the satellite CONSIDERATIONS FOR POLICYMAKERS scenes. The effects of climate change on Cotton, P.A. 2003. Avian migration species’ phenology have been strongly phenology and global climate change. documented. However, in only a few cases has Proceedings of the National Academy of research shown that these changes cause a Sciences 100: 12219-12222. breakdown of ecological systems. Therefore, it is unlikely, with the current level of scientific There is mounting evidence that global climate knowledge on changes in phenology, that change has extended growing seasons, changed government officials will institute policy aimed distribution patterns, and altered the phenology at maintaining species’ phenology in the wake of of flowering, breeding, and migration. For climate change. migratory birds, the timing of arrival on breeding territories and over-wintering grounds is a key Although changes in species’ determinant of reproductive success, phenology are some of the strongest and most survivorship, and fitness. But we know little of accessible evidence for global climate change, the factors controlling earlier passage in long- there are inherent drawbacks to the data. Trends distance migrants. Over the past 30 years in in this field rely primarily on correlations Oxfordshire, U.K., the average arrival and between changes in phenology and changes in departure dates of 20 migrant bird species have temperature. However, causation cannot be both advanced by 8 days; consequently, the inferred from correlations. As a result, one overall residence time in Oxfordshire has cannot state without a doubt that recent increases remained unchanged. The timing of arrival has in spring temperature are causing the observed advanced in relation to increasing winter changes in species’ phenology, although the temperatures in sub-Saharan Africa, whereas the probability of causation is high. timing of departure has advanced after elevated summer temperatures in Oxfordshire. This REFERENCES finding demonstrates that migratory phenology is Badeck, F.W, A. Bandeau, K. Bottcher, D. quite likely to be affected by global climate Doktor, W. Lucht, J. Schaber and S. Sitch. 2004. change and links events in tropical winter Responses of spring phenology to climate quarters with those in temperate breeding areas. change. New Phytologist 162: 295-309.

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Dunn, P.O. and D.W. Winkler. Climate daily temperatures increased during 5 of the 8 change has affected the breeding date of tree months key to gametogenesis in frogs and toads swallows throughout North America. near Ithaca, New York ( U.S.A.). Earliest dates Proceedings of the Royal Society of Biological of calling frogs recorded by Albert Hazen Wright Sciences 266: 2487-2490. between 1900 and 1912 near Ithaca were compared to those from the New York State Increasing evidence suggests that climate change Amphibian and Reptile Atlas Project for 1990– has affected the breeding and distribution of 1999 for the three counties surrounding Ithaca. wildlife. If such changes are due to global Four species are now calling 10–13 days earlier, warming, then we should expect to see large- two are unchanged, and none is calling later. The scale effects. To explore for such effects on data suggest that climate has warmed in central avian reproduction, we examined 3450 nest New York State during this century and has records of tree swallows from across North resulted in earlier breeding in some America. The egg-laying date in tree swallows amphibians—a possible first indication of biotic advanced by up to nine days during 1959 to 1991. response to climate change in eastern North This advance in phenology was associated with America. increasing surface air temperatures at the time of breeding. Our analysis controlled for several Parmesan, C. and G. Yohe. 2003. A potentially confounding variables such as globally coherent fingerprint of climate change latitude, longitude, breeding density and impacts across natural systems. Nature 421: 37- elevation.We conclude that tree swallows across 42. North America are breeding earlier and that the Causal attribution of recent biological trends to most likely cause is a long-term increase in climate change is complicated because non- spring temperature. climatic influences dominate local, short-term Fitter, A.H. and R.S.R Fitter. 2002. Rapid biological changes. Any underlying signal from changes in flowering time in British plants. climate change is likely to be revealed by Science 296: 1689-1691. analyses that seek systematic trends across diverse species and geographic regions; however, The average first flowering date of 385 British debates within the Intergovernmental Panel on plant species has advanced by 4.5 days during Climate Change (IPCC) reveal several the past decade compared with the previous four definitions of a 'systematic trend'. Here, we decades: 16% of species flowered significantly explore these differences, apply diverse analyses earlier in the 1990s than previously, with an to more than 1,700 species, and show that recent average advancement of 15 days in a decade. Ten biological trends match climate change species (3%) flowered significantly later in the predictions. Global meta-analyses documented 1990s than previously. These data reveal the significant range shifts averaging 6.1 km per strongest biological signal yet of climatic change. decade towards the poles (or metres per decade Flowering is especially sensitive to the upward), and significant mean advancement of temperature in the previous month, and spring- spring events by 2.3 days per decade. We define flowering species are most responsive. However, a diagnostic fingerprint of temporal and spatial large interspecific differences in this response 'sign-switching' responses uniquely predicted by will affect both the structure of plant twentieth century climate trends. Among communities and gene flow between species as appropriate long-term/large-scale/multi-species climate warms. Annuals are more likely to flower data sets, this diagnostic fingerprint was found early than congeneric perennials, and insect- for 279 species. This suite of analyses generates pollinated species more than wind-pollinated 'very high confidence' (as laid down by the IPCC) ones. that climate change is already affecting living Gibbs, J.P. and A.R. Breisch. Climate warming systems. and calling phenology of frogs near Ithaca, New Stevens, W.K. 1999. March may be coming York, 1900–1999. Conservation Biology 15: in like a lamb. NY Times: New York, New York. 1175-1178. Visser, M.E. and L.J.M. Holleman. 2001. Because ambient temperature strongly influences Warmer springs disrupt the synchrony of oak reproduction in frogs, the seasonal timing of frog and winter moth phenology. Proceedings of the calling provides a sensitive index of biotic Royal Society of Biological Sciences 268: 289- response to climate change. Over the last century, 294.

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Spring temperatures have increased over the past 25 years, to which a wide variety of organisms have responded. The outstanding question is whether these responses match the temperature- induced shift of the selection pressures acting on these organisms. Organisms have evolved response mechanisms that are only adaptive given the existing relationship between the cues organisms use and the selection pressures acting on them. Global warming may disrupt ecosystem interactions because it alters these relationships and micro-evolution may be slow in tracking these changes. In particular, such shifts have serious consequences for ecosystem functioning for the tight multitrophic interactions involved in the timing of reproduction and growth. We determined the response of winter moth (Operophtera brumata) egg hatching and oak (Quercus robur) bud burst to temperature, a system with strong selection on synchronization. We show that there has been poor synchrony in recent warm springs, which is due to an increase in spring temperatures without a decrease in the incidence of freezing spells in winter. This is a clear warning that such changes in temperature patterns may affect ecosystem interactions more strongly than changes in mean temperature.

5 and some considerations for policymakers are Crop yields, food production and presented. human health STATE OF THE SCIENCE Judy Crawford Agriculture and Crops EXECUTIVE SUMMARY Agricultural production will most certainly There is increasingly clear evidence that be impacted by climate change. Whether those climate change is affecting crops, food produc- impacts are harmful or beneficial depend largely tion and human health. Warming temperatures upon location. Changes in global temperature, have led to earlier crop planting and earlier fruit precipitation and carbon dioxide concentration tree flowering. An unusually severe heat wave are major determinants of agricultural production. during the summer of 2003 destroyed European In middle and higher latitudes, warming tem- food crops and caused an estimated 35,000 peratures may enhance production through deaths. Disease vectors have shifted their ranges lengthened growing seasons, earlier crop matura- northward, as has allergenic pollen. Although tion, earlier harvesting, and potentially two crop- relatively small right now, for both health and ping cycles. Earlier fruit tree flowering and ear- agriculture, impacts in the future are potentially lier planting dates for some crops have already huge. Greater health risks are expected through been observed in Europe. [1] With warmer extreme weather, floods and storms. Fatal heat temperatures, crops may be planted further north, waves will be more frequent. Infectious disease although there are many uncertainties related to a dynamics will change and water sources for northward shift of crops. Along with the plants, drinking and sanitation will be reduced. Overall, pests, weeds and plant diseases are expected to the spread of disease will be enhanced in a expand their northern ranges, and soil fertility warming and variable climate. Models show that may be an issue. Increased precipitation at high at high latitudes, modest increases in tempera- latitudes is projected, while reduced precipitation tures, from 1 – 3 °C, are expected to increase is expected at lower and mid-latitudes. Also at crop yields and food production. At low lati- lower latitudes, increased temperatures may tudes, even slight warming of 1-2 °C is projected cause drier soils and heat stress on plants. These to decrease crop yields. At any latitude, more conditions, especially for crops that are already than 3 °C decreases crop yields. Agriculture is near their maximum temperatures, translate into tremendously adaptable and effective policies reduced plant growth, crop production and food can help to limit the effects of climate change by supply. [2] promoting adaptive capacity. Changes in plant The carbon dioxide effect or ‘fertilization’ variety, improved water and fertilizer manage- refers to the stimulation of photosynthesis at ment, changes in timing and location of crops increased concentrations of CO2. The response can all work to minimize negative impacts. varies according to a plant’s photosynthetic Negative impacts on health are most effectively pathway. Experiments with C3 plants, which met through strengthening of basic public health include the majority of plants and crops such as infrastructures. This is especially important for wheat, rice, soybeans and barley, show yield people in low latitude and tropical developing increases of 10 – 20% at CO2 concentrations of countries who will suffer most from climate 550 ppm. [1] C4 plants, including corn, sugar- change even though they have contributed least cane, sorghum and millet are less responsive, to greenhouse gas emissions. with increased yields of less than 10%. Precipi- tation and temperature changes modify or limit INTRODUCTION the CO2 effect, so that under actual field condi- Crop yields, food production and human tions, yields are uncertain. The impact of ex- health impacts are closely linked issues in cli- treme weather events on crops is another area of mate change. Human survival is dependent upon uncertainty. Increased frequency and intensity of an adequate food supply and food production is storms, heavy rainfall and heat waves are ex- dependent upon climate. This paper briefly ex- pected, however their impacts are difficult to amines key aspects of the state of the science project. The European heat wave during the underlying these topics. Media perspectives are summer of 2003 illustrates the substantial effect explored with examples from contrasting sources of extreme temperatures, in this case 6 °C above average. In France and Italy, many crops were CRAWFORD CROPS, HUMAN HEALTH FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 reduced by 30% or more and total losses were ern Hemisphere with length of the pollen estimated at 19 billion dollars. [1] Crop losses season increased also. from extreme weather may outweigh positive 3) An increase in heat wave related deaths has effects from warming and CO . Results from 2 been documented. [4] over 69 studies modeling the response of cereal yields to climate change produced the following The same 2003 European heat wave that key conclusions and projections: In mid to high destroyed crops was responsible for an estimated latitudes, a warming of 1 – 3 °C, along with a 35, 000 deaths. [5] Important risk factors for CO2 increase and rainfall changes, benefits crop heat-related deaths include age (elderly and chil- yields. However, even slight warming of 1 -2 °C dren), urban location, poverty, and social isola- decreases yields for all major cereals in season- tion. [6] Although European health care sys- ally dry and low latitude areas. Further warming tems are sophisticated, public health response to at any latitude is more negative. Overall global the heat wave was inadequate and few preventive food production then is projected to increase measures were taken to reduce heat-related mor- with temperatures 1-3 °C, but decreases beyond tality. With warming temperatures, more heat that. [1] Models of climate and global crop waves are projected, along with continued range yields are highly complex, yet Lobell developed expansions for disease vectors and pollen. [7] a simple relationship between growing season Ground level ozone, a ‘summertime’ pol- temperatures, precipitation and crop yields. [3] The study reports a negative global yield for lutant, is formed by the reaction of nitrogen ox- wheat, maize and barley with increased tempera- ides, volatile organic compounds, sunlight and heat. Ozone is an irritant gas associated with tures. It also estimates the costs of the negative impact on yields for these crops from 1980 – adverse health effects such as pneumonia, 2000 at roughly $5 billion per year. asthma, other respiratory diseases and premature death. Warming temperatures are expected to Historically, agricultural has been highly increase airborne ozone concentrations. [4] adaptable and productive. Changes in plant va- rieties, fertilization, water management, planting Food insecurity arises from changes in ag- ricultural systems as outlined above. Drought times and pest and pathogen management have brought steady increases in world crop yields. and malnutrition are projected for lower latitude Adaptation to climate change will be necessary. areas already water-stressed including those in sub-Saharan Africa, south Asia, and tropical ar- Adaptive capacity is greatest in developed coun- tries where resources are available. Developing eas of Latin America. In the same locations, countries and subsistence farmers will be highly water scarcity is expected to cause decreased challenged. efficiency of sewers and contamination of water supplies resulting in increased diarrheal diseases, Human Health especially among children. [7] On the other hand, too much water, from flooding and storms, is Climate change can impact human health associated with water-borne and other disease through direct and indirect pathways. Changes in outbreaks. Heavy rainfall can transport micro- temperature, precipitation, sea-level rise and bial and toxic agents and mobilize rodent popula- extreme events are capable of causing direct ad- tions. After rains or floods, mosquito populations verse effects such as heat-related illness, drown- may increase explosively with a resulting in- ing from floods, and traumatic injury during crease in mosquito borne diseases. storms. Indirect effects can occur through cli- mate-related changes in air quality, water quality, Some health benefits are expected from food availability, ecosystems, industry and econ- climate change. Fewer cold-related deaths omy. Currently, human health impacts are be- should result from warming temperatures. Infec- lieved to be in the early stages, with observations tious disease vectors, including malarial mosqui- and evidence of change limited to three key areas: toes, will likely have some contraction in ranges and transmission seasons. These positive effects 1) Warming temperatures are believed to be are small however, and the overall balance of related to altered distributions of disease health impacts is overwhelmingly negative. [4] vectors, including changes in tick distribu- tion and tick-borne infections in Europe. 2) An earlier onset of the spring allergenic pollen season has been noted in the North-

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PERSPECTIVES IN THE MEDIA AND PUBLIC trol, immunization programs, training of health POLICY professionals and community health education. These are the most important and cost-effective Mainstream media perspectives on climate measures available, especially for developing change appear to be shifting even as of this writ- countries. There is really no downside to public ing. The Nobel prize awarded to the IPCC health investment: life expectancy improves, committee and Al Gore likely adds greater au- maternal, infant and child mortalities declines, thority and credibility to the committee’s work. quality of living improves, infectious disease The Draft Synthesis Report of the IPCC Fourth rates decline along with many other benefits. Assessment has been out for three days now and Climate change adds further urgency to the need most media reports appear to accept and promote to develop basic preventive public health pro- the IPCC as the undisputed authority on climate grams. Developed countries also need policies change. Articles covering the Draft Synthesis that will rebuild existing public health programs. report in the New York Times and Washington Inadequate public health response to extreme Post did not even mention alternate views on weather events such as hurricane Katrina in the climate change. With the increasing authority of US and the European heat wave demonstrate that the IPCC, it is possible we will see less main- these organizations were clearly not prepared. stream media coverage of climate skeptics. In addition, policies should promote research and Alternate views do exist however, for ex- development of technologies that will protect ample, the newspaper “Environment and Climate people. Improvements in housing, air condi- News” published by the Heartland Institute. tioning, water purification and pest control will According to their website, the organization’s all be useful for responding to climate based mission is to promote free-market solutions to health impacts. With anticipated water scarcity, social and economic problems, including market- it is important to have policies and a solid regu- based approaches to environmental protection. latory framework for protection of water re- An October, 2007 article, “Health Fears About sources and water quality. Global Warming Are Unfounded”, argued that In the agricultural area, policies that pro- warmer temperatures are healthier because of mote adaptive capabilities are essential. In order fewer cold-related deaths. [8] The article ne- to maintain crop yields during climate change, glects to mention that cold benefits will not off- farmers will need to respond rapidly with set all of the negative effects from heat and fo- changes in plant variety, water and fertilization cuses only on developed countries. Supporting practices, and timing and location of crops. Such studies are discussed, but citations are not given, adjustments are most difficult for small farmers; so they cannot be identified. In all, this is an policies should support farmers in vulnerable opinion piece containing selective information, locations where food shortages are expected. but with the appearance and flow of a science- Investment in agricultural research and training based article. Because it looks and sounds like is important as is access to credit for capital im- science, it may influence some readers, espe- provements. Financial incentives, subsidies, and cially those who do not understand peer- crop insurance are other measures that may be reviewed literature. part of an overall strategy to support adaptation in agriculture. Regulatory structures that protect CONSIDERATIONS FOR POLICYMAKERS and preserve land and water resources are also In the human health area, policies that serve important. to strengthen public health infrastructures are critically important. A comprehensive strategy Finally, policymakers must be aware of a to support public health internationally will be basic inequity related to climate change; coun- most effective in preparing for and responding to tries that have generated the least greenhouse gas climate-related health impacts. Because health emissions will bear most of the negative impacts impacts are only just emerging, there is time to in health and agriculture. A strategy for com- develop public health capacity. This is particu- pensation and support should be considered. larly important for developing nations, who are most vulnerable. Strong public health organiza- REFERENCES tions are actively involved in disease surveil- 1. Easterling, W.E., et al., Food, fibre and lance, sanitation programs, emergency prepared- forest products, in Climate Change 2007: Im- ness and response, water and air pollution con- pacts, Adaptation and Vulnerability. Contribu-

3 CRAWFORD CROPS, HUMAN HEALTH FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 tion of Working Group II to the Fourth Assess- creased temperatures. Based on these sensitivi- ment Report of the Intergovernmental Panel on ties and observed climate trends, we estimate Climate Change. 2007, Cambridge University that warming since 1981 has resulted in annual Press: Cambridge. p. 273-313. combined losses of these three crops represent- ing roughly 40 Mt or $5 billion per year, as of 2. Rosenzweig, C. (2003) Climate Change 2002. While these impacts are small relative to and Agriculture: Mitigation and Adaptation. the technological yield gains over the same pe- Senate Committee on Environment and Public riod, the results demonstrate already occurring Works Subcommittee on Clean Air, Climate negative impacts of climate trends on crop yields Change, and Nuclear Safety, Available at: at the global scale http://epw.senate.gov/108th/Rosenzweig_070803 .htm 4. Confalonieri, U., et al., Human health. Climate Change 2007: Impacts, Adaptation and 3. Lobell, D.B. and C.B. Field (2007) Vulnerability. , in Contribution of Working Global scale climate-crop yield relationships and Group II to the Fourth Assessment Report of the the impacts of recent warming. Environ Res. Lett Intergovernmental Panel on Climate Change, 2, DOI: 10.1088/1748-9326/2/1/014002 M.L. Parry, et al., Editors. 2007, Cambridge Abstract - Changes in the global University Press: Cambridge. p. 391-431. production of major crops are important drivers 5. Vandentorren, S., et al., Mortality in 13 of food prices, food security and land use deci- French cities during the August 2003 heat wave. sions. Average global yields for these commodi- Am J Public Health, 2004. 94(9): p. 1518-20. ties are determined by the performance of crops in millions of fields distributed across a range of Abstract - We observed the daily management, soil and climate regimes. Despite trend in mortality rates during the 2003 heat the complexity of global food supply, here we wave in 13 of France's largest cities. Mortality show that simple measures of growing season data were collected from July 25 to September temperatures and precipitation—spatial averages 15 each year from 1999 through 2003. The con- based on the locations of each crop—explain junction of a maximum temperature of 35 de- ~30% or more of year-to-year variations in grees C and a minimum temperature of 20 de- global average yields for the world's six most grees C was exceptional in 7 cities. An excess widely grown crops. For wheat, maize and barley, mortality rate was observed in the 13 towns, with there is a clearly negative response of global disparities from +4% (Lille) to +142% (Paris) yields to increased temperatures. Based on these 6. McGeehin, M.A. and M. Mirabelli, The sensitivities and observed climate trends, we potential impacts of climate variability and estimate that warming since 1981 has resulted in change on temperature-related morbidity and annual combined losses of these three crops rep- mortality in the United States. Environ Health resenting roughly 40 Mt or $5 billion per year, as Perspect, 2001. 109 Suppl 2: p. 185-9. of 2002. While these impacts are small relative to the technological yield gains over the same Abstract - Heat and heat waves are pro- period, the results demonstrate already occurring jected to increase in severity and frequency with negative impacts of climate trends on crop yields increasing global mean temperatures. Studies in at the global scale Changes in the global produc- urban areas show an association between in- tion of major crops are important drivers of food creases in mortality and increases in heat, meas- prices, food security and land use decisions. Av- ured by maximum or minimum temperature, heat erage global yields for these commodities are index, and sometimes, other weather conditions. determined by the performance of crops in mil- Health effects associated with exposure to ex- lions of fields distributed across a range of man- treme and prolonged heat appear to be related to agement, soil and climate regimes. Despite the environmental temperatures above those to complexity of global food supply, here we show which the population is accustomed. Models of that simple measures of growing season tempera- weather-mortality relationships indicate that tures and precipitation—spatial averages based populations in northeastern and midwestern U.S. on the locations of each crop—explain ~30% or cities are likely to experience the greatest num- more of year-to-year variations in global average ber of illnesses and deaths in response to changes yields for the world's six most widely grown in summer temperature. Physiologic and behav- crops. For wheat, maize and barley, there is a ioral adaptations may reduce morbidity and mor- clearly negative response of global yields to in- tality. Within heat-sensitive regions, urban popu-

4 CRAWFORD CROPS, HUMAN HEALTH FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 lations are the most vulnerable to adverse heat- related health outcomes. The elderly, young children, the poor, and people who are bedridden or are on certain medications are at particular risk. Heat-related illnesses and deaths are largely preventable through behavioral adaptations, in- cluding the use of air conditioning and increased fluid intake. Overall death rates are higher in winter than in summer, and it is possible that milder winters could reduce deaths in winter months. However, the relationship between win- ter weather and mortality is difficult to interpret. Other adaptation measures include heat emer- gency plans, warning systems, and illness man- agement plans. Research is needed to identify critical weather parameters, the associations be- tween heat and nonfatal illnesses, the evaluation of implemented heat response plans, and the ef- fectiveness of urban design in reducing heat re- tention. 7. Patz, J.A. and R.S. Kovats, Hotspots in climate change and human health. BMJ, 2002. 325(7372): p. 1094-8. 8. Singer, S.F. and D.T. Avery, Health Fears About Global Warming are Unfounded, in Environment and Climate News. October 2007. p.10.

5 a Union of Concerned Scientists report related to Observations and Predictions for the Northeast. In addition, these reports and the Northeast articles will be discussed in terms of communication theory's "framing" and the "two- Kristin Cleveland step flow of popularization" model (Nisbet & Mooney, 2007; Nisbet, 2007). EXECUTIVE SUMMARY In recent years, New York and other STATE OF THE SCIENCE northeastern states (Pennsylvania, New Jersey, In 2007 the Northeast Climate Impacts and the New England states) have been Assessment (NECIA) team reported on current experiencing a variety of "… changes [that] are and predicted impacts of climate change for the consistent with those expected to be caused by northeastern region of the United States (UCS global warming," (UCS, 2000, p. ix). This paper NY, 2007; UCS Summary, 2007). Some changes identifies several of these current natural already observed are as follows: resource changes and highlights some potential future changes, focusing on changes that in turn - More frequent days with will likely affect public health, alter economic temperatures above 90ºF traditions and regional identity, and have an - A longer growing season impact on water resources in New England and in New York's Catskill Mountain region. In - Less winter precipitation falling as addition, the ways in which information about snow and more as rain changes to the Northeast's natural resources is - Reduced snowpack and increased presented in the media and to public decision snow density makers are analyzed in light of suggestions from several communication and public education - Earlier breakup of winter ice on scholars. lakes and rivers - Earlier spring snowmelt resulting in INTRODUCTION earlier peak river flows A 2007 Gallup Panel poll reveals that - Rising sea-surface temperatures and while the majority of Americans are aware of sea levels (UCS Summary, 2007, ix) and somewhat concerned about global warming, "only a small fraction of the public names global The NECIA reports also identify changes warming in unaided measures of perceived predicted to occur to the region's natural problems facing the nation or as a top resources by mid- or late-century as a result of government priority," (Saad). The Gallup Panel changes in climate regimes, based on lower- and found this relatively low ranking of the climate higher-emissions scenarios. These changes are change issue to be due at least in part to the fact likely to alter, and in some cases threaten, the that Americans perceive global warming effects region's social identity, its traditional economic to be distant, rather than likely to occur within base, and the health of the region and its the next few decades. Numerous other factors are inhabitants. also likely to contribute to this low ranking, Noting, "[t]he character and economy of including variations in political affiliations (Saad, the Northeast have been profoundly shaped over 2007) and other interpretive communities the centuries by its varied and changeable (Leiserowitz, 2005), the manner in which climate climate," the NECIA report observes that change is portrayed in the media (Nisbet, 2007), changes to the region's climate are likely to alter and a sense that the potential effects of climate both this character, which is closely tied to change will be geographically remote regional identity, and to alter the economy that is (Leiserowitz, 2005). Therefore, as a step towards based upon features of that character (USC learning how to improve communication of Summary, 2007, ix). For instance, based on the scientific information to better help Americans higher-emissions scenario, reductions of relate to the issues of climate change, this paper snowfall and shortening of winter temperatures will focus on climate change impacts in the will most likely eliminate downhill ski northeastern United States, examining two operations from all parts of the region except scientific studies concerning water resources in western Maine (x). Even the lower-emissions New York and New England and two sections of scenario will "shorten the average ski and CLEVELAND NORTHEAST PERSPECTIVES FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 snowboard seasons, increase snowmaking Atlantic Salmon and other valued northern requirements, and drive up operating costs" (xi). species (Huntington, 2003). In New York State, recent decades have seen a In addition to potential changes to the rise in average annual temperatures of over 1.5ºF, Northeast's traditional economy and regional with winter average temperatures rising 4ºF identity, climate change may also be detrimental (UCS NY, 2007, 1). Predictions for additional to residents' health. Under either emissions winter temperature increases by the end of this scenario, conditions promoting the growth of century are 8ºF-12ºF under the higher emissions mosquitoes and ticks may lead to increases in the scenario, and 4ºF-6ºF under the lower scenario spread of diseases carried by these animals. Also, (1-2). Such increases would lead to more of New "[t]he number of days over 90ºF is expected to York's winter precipitation falling as rain rather triple in many of the region's cities, including than snow, and more winter precipitation overall Boston, Buffalo, and Concord, NH" (xi). Under (approximately 20-30% increase under the lower the higher emissions scenario, many Northeast scenario, and slightly more under the higher cities could have at least 14 days over 100ºF scenario) (2). This will reduce winter ski and during the average late-century summer (x). snowmobile seasons in New York's Adirondack Summer temperatures in New York City are Mountain region. Skiing, snowmobiling, and likely to exceed 100ºF for over 25 days by the other snow-related tourism is an important end of the century under the higher scenario component of the Adirondack region's winter (UCS NY, 2007, 1-2). Such high temperatures in economy (5). regions where people are unaccustomed to these Another character-economy alteration extremes can increase the number of heat-related relates to New England fall-foliage tourism, as deaths, especially to fragile populations such as "climate conditions suitable for the poor, the elderly, and the sick (McGeehin & maple/beech/birch forests would shift" either out Mirabelli, 2001, p. 186). Also, by late-century, of the southern parts of the region, if future ground-level ozone pollution, which contributes greenhouse gas emissions were closer to the to respiratory ailments, is expected to rise by lower-emissions scenario, or would move even 50% under the lower-emissions scenario, and by further northward, if the future emissions are 200% under the higher-emissions scenario (UCS closer to the higher-emissions scenario (USC Summary, 2007, x-xi). Finally, predicted sea Summary, 2007, x-xi). The shift from the level rises of at least 1 – 2 feet (lower scenario) dramatic palette of maple/beech/birch's reds, and increasing frequencies of severe flooding for oranges and yellows to the more monotone coastal cities (either scenario) will likely cause yellows and browns of the likely successors, the both health and economic problems, at least until oak/hickory forests, may reduce the numbers of communities adapt to such changes (xi). people traveling to the Northeast for scenic Changing temperature patterns and tourism, and will certainly alter the identity of precipitation regimes in the Northeast may also the region. affect regional drinking water supplies (Burns, Regional character and economics will 2006) and water availability for agriculture and also be affected by changes to marine and forests, as well as for aquatic species aquatic habitat, which provides the conditions (Huntington, 2003). In New York's Catskill for the current fishing industry. The NECIA region, such changes may alter potential team reports that under the higher-emissions evapotranspiration rates so that, even with scenario, the predicted "increasing water predicted increases in regional runoff amounts, temperatures may make the storied fishing the net yield to New York City's water supply grounds of Georges Bank unfavorable for cod" will be reduced (Burns, 2006). New York farms (UCS Summary, 2007, x). Even under the lower- may have to spend more money on irrigation, as emissions scenario, Georges Bank will be less short-term droughts are likely to occur more inhabitable for young cod, and under both often (UCS NY, 2007, 5). Overall average runoff scenarios, the Long Island lobster industry will rates in New England could drop, although also decline to the point where it will likely be numerous factors affecting these estimates, gone by mid-century (xi; UCS NY, 2007, 5). In "…the site-specific combination of precipitation, rivers throughout New England, future climate vegetation, soils, geology, aquifer characteristics, changes could potentially lead to reduced river and microclimate," make it difficult to predict flows, affecting habitat for the endangered specific impacts to particular river basins (Huntington, 2003, 199).

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PERSPECTIVES IN MEDIA AND PUBLIC also recommends branching out from the news to POLICY other genres of popular culture, such as the entertainment media and "celebrity culture." Matthew Nisbet, a specialist in Politicians are learning this trick, recognizing communication of scientific information, that they can get a wider audience on "The Daily observes that the growing number and Show" than on the "MacNeil/Lehrer NewsHour." accessibility of choices in modern media make Finally, Nisbet explains the "importance of readers increasingly likely to select media 'opinion-leaders' in … [diffusing]… messages content based on interest preferences and to within local communities." Nisbet recommends: select media sources based on political, religious, or other ideologies. This "fragmented media When "surges" in communication and system" can lead to "…selective acceptance of public attention are needed – such as surrounding like-minded arguments and opinions," making it the release of a future section of the IPCC report increasingly difficult for readers to attend to a or a major study by the National Academies of diversity of information (Nisbet, 2007). Nisbet Science – opinion leaders can be activated with recommends three techniques to manage this talking points to share in conversations with information situation in order to get scientific friends and co-workers, in emails, in blog posts, information to the public. First, explaining that, or letters to the editor. These "scientific citizens" "…citizens do not use the news media as would not formally speak on behalf of or scientists assume," Nisbet and Mooney (2007) represent the scientific organization, but instead argue, "Without misrepresenting scientific their effectiveness would stem from their ability information on highly contested issues, scientists as co-workers and friends to communicate must learn to actively 'frame' information to climate change in a way that makes it personally make it relevant to different audiences." and politically relevant. (Nisbet, 2007) Framing is a way of making an issue Some additional alternative methods of personally relevant, defining it through communicating information about climate "[organizing] central ideas [and]… giving some change include holding community workshops aspects greater emphasis [in order to] …allow and other forms of public information sessions citizens to rapidly identify why an issue matters, (Taylor, Gray, & Schiefer, 2006). Such who might be responsible, and what should be techniques can be particularly effective in done" (Nisbet & Mooney, 2007). Noting the helping community residents understand and prevalence of "science-intensive" messages adapt to the changes that will occur in their local provided by researchers, Nisbet and Mooney environment. explain that "much of the public likely tunes out these technical messages" and instead attend to CONSIDERATIONS FOR POLICYMAKERS messages that are framed in ways that they can For policymakers to devise plans to, at a connect to issues they better understand, such as minimum, manage the effects of climate change "economic development" or "social progress" for their constituencies, and perhaps to reduce (2007). In addition, emphasizing only the some of the potential harmful effects, they need technical details of a study opens up these details to have as much information as is practical for to be interpreted by politicians, business and them to work with, and they need to understand industry leaders, and others who have a the relevance of various levels of uncertainty and particular agenda. Some of the frames that have of variations between studies. The New England been applied to the climate change issue are Regional Assessment addresses this issue of "unfair economic burden" and "scientific uncertainty and predictive model variation by uncertainty," which have been countered by the recommending "an assessment approach … [that] "catastrophe" frame of drowning polar bears and allows individual regions or sectors to consider destructive hurricanes, which in turn "have 'what if' cases that reflect educated guesses based evoked charges of 'alarmism' and further battles" on the nature and importance of specific regional (Nisbet & Mooney, 2007). Nisbet and Mooney and sector vulnerabilities." Huntington reflects explain that providing technical information this advice in his caution to readers that, "The along with a frame such as "public value of the empirical relationships [examined in accountability" can help media readers to this study] is in understanding likely average understand a perspective that suggests their role runoff response for a region rather than and the role of government in dealing with the prediction for a specific river basin" (2003,199). implications of that technical information. Nisbet

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Policymakers must recognize the value of maximum March air temperature. This change "educated guesses," and understandings of indicates an increased supply of water to general regional impacts rather than specific reservoirs earlier in the year. Additionally, the certainties, considering the danger of ignoring supply of water to reservoirs at the beginning of these likelihoods while awaiting certainties and winter is greater as indicated by the timing of the specifics. For this to happen, scientists must be greatest increases in precipitation and runoff – willing to explain such values to policymakers. both occurred during the summer and fall. The future balance between changes in air REFERENCES temperature and changes in the timing and Burns, D.A., Klaus, J., & McHale, M.R. amount of precipitation in the region will have (2007). Recent climate trends and implications important implications for the available water for water resources in the Catskill Mountain supply in the region. region, New York, USA. Journal of Hydrology, Huntington, T.G. (2003). Climate warming 336(1-2), 155-170. could reduce runoff significantly in New Abstract: Climate scientists have concluded that England, USA. Agricultural and Forest the earth's surface air temperature warmed by Meteorology, 117(3-4), 193-201. 0.6ºC during the 20th century, and that warming Abstract: The relation between mean annual induced by increasing concentrations of temperature (MAT), mean annual precipitation greenhouse gases is most likely to continue in (MAP) and evapotranspiration (ET) for 38 the 21st century, accompanied by changes in the forested watersheds was determined to evaluate hydrologic cycle. Climate change has important the potential increase in ET and resulting implications in the Catskill region of decrease in stream runoff that could occur southeastern New York State, because the region following climate change and lengthening of the is a source of water supply for New York City. growing season. The watersheds were all We used the non-parametric Mann-Kendall test predominantly forested and were located in to evaluate annual, monthly, and multi-month eastern North America, along a gradient in MAP trends in air temperature, precipitation amount, from 3.4ºC in New Brunswick, CA to 19.8ºC in stream runoff, and potential evapotranspiration northern Florida. Regression analysis for MAT (PET) in the region during 1952-2005 based on versus ET indicated that along this gradient ET data from 9 temperature sites, 12 precipitation increased at a rate of 2.85 cmº-1 increase in MAT sites, and 8 stream gages. A general pattern of (±0.96 cmºC-1, 95% confidence limits). General warming temperatures and increased circulation models (CGM) using current mid- precipitation, runoff, and PET is evident in the range emission scenarios project global MAT to region. Regional annual mean air temperature increase by about 3ºC during the 21st century. increased significantly by 0.6ºC per 50 years The inferred, potential, reduction in annual during the period; the greatest increases and runoff associated with a 3ºC increase in MAT for largest number of significant upward trends were a representative small coastal basin and an inland in daily minimum air temperature. Daily mountainous basin in New England would be maximum air temperature showed the greatest 11-13%. Percentage reductions in average daily increase during May through September. runoff could be substantially larger during the Regional mean precipitation increased months of lowest flows (July – September). The significantly by 136 mm per 50 years, nearly largest absolute reductions in runoff are likely to double that of the regional mean increase in be during April and May with smaller reduction runoff, which was not significant. Regional mean in the fall. This seasonal pattern of reduction in PET increased significantly by 19 mm per 50 runoff is consistent with lengthening of the years, about one-seventh that of the increase in growing season and an increase in the ratio of precipitation amount, and broadly consistent rain to snow. Future increases in water use with increased runoff during 1952-2005, despite efficiency (WUE), precipitation, and cloudiness the lack of significance in the mean regional could mitigate part or all of this reduction in runoff trend. Peak snowmelt as approximated by runoff but the full effects of changing climate on the winter-spring center of volume of stream WUE remain quite uncertain as do future trends runoff generally shifted from early April at the in precipitation and cloudiness. beginning of the record to late March at the end of the record, consistent with a decreasing trend in April runoff and an increasing trend in

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Leiserowitz, A.A. (2005). American risk perceptions: is climate change dangerous? Risk Analysis 25(6), 1433-1442. McGeehin, M.A. & Mirabelli, M. (2001). The potential impacts of climate variability and change on temperature-related morbidity and mortality in the United States. Environmental Health Perspectives 109(2), 185-189. New England Regional Assessment (1999). NERA Model White Paper. Retrieved from www.necci.sr.unh.edu/reports.html on November 12, 2007. Nisbet, M. (2007). A "two-step flow of popularization" for climate change: recruiting opinion leaders for science. Retrieved October 24, 2004 from the Community for Skeptical Inquiry website: http://www.csicop.org/scienceandmedia/climate. Saad, L. (2007, March). To Americans, the risks of global warming are not imminent. Retrieved 11/12/07 from www.gallup.com/poll/26842/Americans-Risks- Global-Warming Taylor, M.E., Gray, P.A., & Schiefer, K. (2006). Helping Canadians adapt to climate change in the Great Lakes coastal zone. The Great Lakes Geographer, 13(1), 14-25. Abstract: As global warming increases, Great Lakes coastal communities will be subjected to significant climate changes driven by increasing temperature, changing precipitation and wind patterns, and a potential increase in the frequency of severe events such as windstorms and ice storms. Climate change will impact all life in every ecosystem, and people who live and work in these systems will need to adapt in a variety of ways. In response, a number of agencies and organizations have partnered to assist Great Lakes coastal communities in their efforts to identify and assess adaptation options. To date, workshops have been completed in Belleville (Lake Ontario) and Parry Sound (Lake Huron). This paper reviews some of the known and potential impacts that will result in our near Presqu'ile Provincial Park, Lake Ontario and in Sturgeon Bay, Lake Huron, and proposes a checklist of actions that could provide the basis for an adaptation protocol. Union of Concerned Scientists (2007). Northeast Climate Impacts Assessment Executive Summary. Retrieved September, 2007 from www.climatechoices.org.

5 GDP is positively correlated with fossil fuel use A survey of climate change (Cleveland et al. 1984). Assuming that the mitigation technologies in Pacala relationship exemplified in the demographic transition is real, then the global standard of and Socolow (2004) living (e.g. GWP, gross world product) must be Tony Eallonardo increased in order to stabilize our environmental impacts (not to mention other ethical and EXECUTIVE SUMMARY sovereignty issues). Yet bringing the global standard of living up to levels enjoyed by It is now widely known and well accepted developed nations would lead to massive that anthropogenic green house gas emissions are increases in green house gas emissions. modifying the global climate in a syndrome of Therefore, another way of considering carbon ways described as The Greenhouse Effect or mitigation is the decoupling of wealth production Climate Change. There is also broad based from fossil fuel use. Pacala and Socolow (2004) agreement that unless business-as-usual activities provide a framework for doing just that. are radically changed over the next decades, significant alteration of the biosphere is likely Pacala and Socolow (2004) state that (IPCC 2007a,b). The risk of inaction on climate humanity has the technological know-how to change, which briefly stated amounts to limit CO2 emissions to approximately a doubling increased stress to hundred of millions of of pre-industrial levels, but what needs to happen humans (IPCC 2007b), outweighs the cost of is a scaling up of a suite of these technologies. action. The IPCC (2007c) states that the cost of Stabilizing atmospheric concentrations of CO2 stabilizing atmospheric CO2 at approximately near 500 ppm requires that global emissions be double pre-industrial levels will range from 0.2- held at about 7 Pg C/yr, while business as usual 2.5% of global GDP. Under modeling scenarios will put us at about 14 Pg C/yr emissions by where mitigation improves market efficiency, 2054. The authors envision a “stabilization GDP gains are predicted (IPCC 2007c). Pacala triangle” comprised of the difference between and Socolow (2004) state that humanity has the these two emission rates over a 50 year time span. technological know-how to limit CO2 emissions They divide the stabilization triangle into seven to approximately a doubling of pre-industrial potential mitigation solutions (e.g. wedges) that levels over the next 50 years and they provide a each represents “an activity that reduces list of potential mitigation solutions. This paper emissions to the atmosphere that starts at zero explores technologies itemized in Pacala and today and increases linearly until it accounts for Socolow (2004), namely, carbon capture and 1 Pg C/yr of reduced carbon emissions in 50 storage, hydrogen fuels, biomass derived ethanol, years.” Each wedge totals 25 Pg C to be and conservation tillage. mitigated over 50 years. Citing the fact that gross world production has increased by 3% while INTRODUCTION energy consumption has increased by only 2%, the authors indicate that the global economy has Mitigation in the context of global been on a trajectory of decarbonization since the environmental issues time of Cleveland et al. (1984). This decreasing Greenhouse gas (aka Carbon) mitigation is energy intensity (emissions/$GDP) has led to any activity that reduces green house gas avoiding the need for three additional wedges. emissions to the atmosphere. While a variety of The authors present what they call is a non- carbon mitigation technologies are currently exhaustive list of 15 options for the seven available and will be discussed further below, it wedges: is worth noting that ultimately most (if not all) environmental issues are driven by the increasing 1) Increasing transportation fuel economy human population and that we are met at the from 30 to 60 mpg outset with the following irony: 2) Reduce fuel use by halving the miles driven Since increasing human population is the 3) Reduce building emissions by 20% ultimate driver of environmental issues, there is a need to reduce the global population growth rate. 4) Increase coal plant efficiency from today’s Human population growth rate is negatively 32% to 60% correlated with GDP (the so-called ‘demographic transition,’ Goldstein 1999). Yet production of EALLONDARDO MITIGATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007

5) Replace coal with gas by increasing gas component of wedge portfolio. For one wedge’s power production by 300% worth of CCS, approximately 120 million barrels of liquid CO would need to be buried every day 6) Capture CO at power plant: apply carbon 2 2 (Shepard and Socolow 2007). While there is capture and storage (CCS) at 800 GW of evidence that there is space for the several coal or 1600 GW of natural gas hundred years of CO2 emissions (Shepard and 7) Capture CO2 at hydrogen plant: apply CCS Socolow 2007, Damen et al. 2006), at least to 250 Mt H2/yr from coal or 500 Mt H2/yr several hundred CCS systems would have to from natural gas come on line in the next 50 years to stabilize emissions (IPCC 2005). 8) Capture CO2 at a coal to synfuels plant: apply CCS to the production of 30 million There are two relatively well-known barrels/day of synfuels production methods by which carbon capture can occur: the so-called pulverized coal (PC) process where the

9) Increase nuclear capacity by 100% carbon is removed post combustion and the 10) Replace coal with wind: increase wind integrated gasification combined cycle (IGCC) capacity by 4900% where the carbon is removed after the coal is gasified but before it is burned. In most current 11) Replace coal with photovoltaics (PV): scenarios, the PC process uses the solvent increase PV by 69900% monoenthanolamine (MEA) to capture CO2 in 12) Replace hybrid cars with wind derived H2 the gas, however significant heating is required cars: increase wind capacity by 9900% to remove the captured CO2 from the MEA for th compression and storage. Due to this inefficiency, 13) Convert 1/6 of earth’s cropland to biofuel many other carbon collection methods ranging production from nano-technology biological catalysts are 14) Stop tropical deforestation and double the being tested (Kintisch 2007a), but in the mean current rate of afforestation projects time, IGCC process appears to be the favored technology (Kintisch 2007b). 15) Apply conservation tillage to all cropland Risks and management implications I will further explore key technologies associated with transport, injection and storage associated with these potential wedges: CCS, of CO2 are as follows (Damen et al. 2006): hydrogen fuel, biofuels, and conservation tillage. These technologies were chosen for further study 1) The main risk associated with transporting due to their broad applicability and/or potentially and injecting CO2 are leaks in transport and controversial issues. While Pacala and Socolow well head failures. However, given the (2004) do not explicitly discuss interactions positive track-record of existing CO2 between wedges, I will aim to reveal potential pumping operations for oil recovery, the synergies/controversies in the ‘State of the risk is quite low. Science’ section. 2) Risks in geological storage include: leaks, earthquakes and other ground movements, STATE OF THE SCIENCE and damage to freshwater aquifers. Model Carbon capture and storage results suggest that CO2 escaping from failed geological reservoirs located 700- Carbon capture and storage (CCS) is the 1000 m below the earth’s surface would collection, purification, liquification and take at least 5,500 and possibly up to placement of carbon dioxide emissions in 500,000 yr to surface. While “cap rock” geologic reservoirs or the oceans. Significant failures may occur in geological reservoirs, questions remain at all steps in this process. number of secondary processes (e.g. CO2 Since the heavy ecological toll of increasing capture in liquids, fossil fuels, heavy soils). oceanic carbon concentrations is well known, I The strongest consideration for CCS will not consider the oceans as a potential activities should be given to sites with the reservoir. Given the high relative abundance and greatest number and extent of these inexpensiveness of coal, Rau and Caldiera (2007) secondary capture mechanisms. While CO2 state that two coal-fired power plants are to be can damage the integrity of clay shales, the built every two weeks over the next 25 years. authors site other studies that have shown Therefore, CCS will likely be a central that mineral precipitation may decrease

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CO2 permeability, and variety of seismic Outstanding issues needing resolution are issues can be avoided by keeping storage associated with the following topics: pressure below the geostatic pressure. 1) Distribution: At room temperature, 3) Potential “point sources” for CO2 leakage hydrogen occupies 2000-3000 times the are abandoned wells that have been space per energy unit than gasoline does decommissioned improperly or that have (Dixon 2007); therefore besides the energy deteriorated. Abandoned wells represent needed to create hydrogen fuel, energy is one of the more significant CCS risks, needed to liquefy it. however at least this risk can be managed 2) Technology life span: The Proton Exchange through knowing the location and Membrane (PEM) is largely the preferred conditions of all decommissioned wells on fuel cell type, but it is expensive and needs site, and site selection should factor out replacement every 31,000 miles (Difiglio areas with excessive wells. and Gielen 2007). 4) Considerable uncertainly remains in 3) Overall cost: The life-cycle analysis of regards to polluting fresh water aquifers Difiglio and Gielen (2007) suggests that with brine displaced from CCS operations. significant progress must be made in the A potential natural analog for a worst case production, transport and use of hydrogen scenario was in 1986 when the hypolimneon of fuel to reduce what are currently Lake Nyos, Cameroon became supersaturated prohibitive costs. with volcanic CO and rapidly overturned. This 2 Difiglio and Gielen (2007) report that the event released CO that settled into a nearby 2 relative mitigation cost of utilizing fuel cell village and killed approximately 1700 people. vehicles decreases as total driving time increases, Loss of human life on this scale would likely not and that passenger cars are, surprisingly, not occur from a failure from geological reservoir used enough to realize mitigation benefits in unless the CO leaked into a surface water body. 2 terms of dollars. They suggest initiating Therefore site selection committees should also hydrogen technologies in trucks, buses, trains, factor out any sites with surface water bodies and airplanes—end uses that have a much greater that could receive gas leakage. The Lake Nyos annual use. example shows that type of the type of the release (in terms of rapidity and topography (In An alternative view is provided by Lovins the Lake Nyos example the gas cloud was able to and Cramer (2004). They have designed a fuel remain intact and settle in the village)) is likely cell vehicle that reduces required propulsive more important than the volume of release when energy by approximately 66%, which, in their considering short term human health impacts view, moots any argument on the expense of fuel (Damen et al. 2006). cells because the required engines and tanks can be smaller and more economical. Hydrogen fuel: attractive potential with a CCS requirement and logistical issues Biomass ethanol production as an Since the transport sector is responsible for alternative fuel option a significant amount of the increase in world oil One wedge worth of carbon may be demand over the last 30 years (Difiglio and accounted by the use of biofuels however Gielen 2007), zero-carbon fuels could be an bioenergy cropping systems require fossil fuel important mitigation tool. While hydrogen has inputs, emit non-carbon greenhouse gases, and well-known advantages such as zero carbon entail important ethical questions. Adler et al. emissions and energy independence, it also has (2007) provide a life cycle assessment of many current disadvantages. For example, low bioenergy cropping systems. The authors cost hydrogen production, storage and considered potential biofuel crops for North conversion technologies are currently America: corn, soy, alfalfa, reed canarygrass, unavailable (Dixon 2007). The most practical alfalfa, and hybrid poplar. They found that production of hydrogen is from fossil fuel combined corn grain and stover harvest had the sources where the conversion efficiency is less highest ethanol yield (8 MJ/m2/yr), with than one, and which would necessitate the switchgrass and hybrid poplar tied for second at development of CCS (Difiglio and Gielen 2007). (7-8 MJ/m2/yr). When crop inputs and greenhouse gas emissions were considered,

3 EALLONDARDO MITIGATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 switchgrass and hybrid poplar displace the rotation cycle, and use of manure/biosolids for greatest amount of fossil fuels (150 to 160 g CO2 soil amendment instead of inorganic fertilizers. equivalents/m2/yr). Besides increased machinery RMPs also reduce climate change stresses on emissions, traditional cropping systems (e.g. crops by increasing soil quality. corn, soy) have 100 to 200% greater N O 2 Recommended management practices result emissions and 50% greater CO emissions from 2 in increased formation of stable soil aggregates, the soil than switchgrass and hybrid poplar increased soil humification, increased eluviation systems. Across all cropping systems the greatest of soil C to subsoils, and increased leaching of amount of CO emissions was associated with 2 carbonates to groundwater (which is also harvesting—up to 80-90% for switchgrass and considered a form of C sequestration (Raymond hybrid poplar. Therefore, small increases in and Cole 2003)). The greatest C sequestration harvesting efficiency could have relatively large potential is in relatively cool and humid effects on the overall system carbon balance. environments on relatively heavy textured soils One wedge of biofuels is 250 x 106 that also have sufficient levels of humus building hectares or about 1/6th of total cropland (Pacala blocks (e.g. N, P, and S). On the other hand, and Socolow 2004). One is left wondering how a structurally reduced soils (e.g. those dominated 40-50% bigger global population (U.S. Census by kaolinite clays) that are nutrient-poor and in Bureau 2006) will be fed on 16% less land by warm regions have the greatest capacity to 2050. volatilize carbon. The global mean rate of soil C sequestration for conversion of conventional to Righelato and Spracklen (2007) collated a no-till cropping is 400-600 kg/ha/yr which variety of life cycle analyses to show that, “In all equates to a 0.6 to 1.2 Pg C/yr across all crop cases, forestation of an equivalent area would land (Rosenzweig and Tubiello 2007). This sequester two to nine times more carbon over a sequestration rate is consistent with “one wedge” 30-year period than emissions avoided by the use of carbon or 1 Pg C sequestered per year in of biofuel.” They suggest that forest restoration Pacala and Socolow (2004). should be favored over biofuel production for this reason. While this suggestion makes sense for lower latitude areas, it has been shown that PERSPECTIVES IN THE MEDIA AND PUBLIC reforestation in temperate zones has a net POLICY radiative forcing due to the relatively low albedo Time magazine recently published a of forests (Myre and Myre 2003). One must also special section: Global Warming (Knauer 2007). consider that forests periodically burn. Therefore The magazine is packed full of striking, highly the most logical solution may be to utilize land effective images related to the sources, area for biofuel production where forest radiative environmental impacts and mitigation solutions forcing would outweigh carbon sequestration of climate change. There is a consistent theme effects or where forests fires are relatively across the magazine’s articles that climate frequent; and during biofuel production utilize change’s sources are anthropogenic, the agricultural RMPs (described next) to facilitate environmental impacts are and have been carbon storage in the soil. coming into fruition, but that mitigation solutions are both practical, economical, and Recommended management practices (aka available to both average citizens and industry. Conservation Tillage) The magazine features “FAQs” sections for the While approximately 300 Pg of C have climate change neophytes and puts answers to been emitted by fossil fuel combustion over the complex climate questions in understandable, last century an additional 150 GT has been from informative terms. agricultural soil emissions (Rosenzweig and In regards to mitigation, the magazine is Tubiello 2007). The causes of agricultural CO2 packed with examples of mitigation solutions emissions are well known: soil drainage, across all sectors of the economy; incorporated plowing, removal of crop residue, fire, inorganic with this effort are a series of profiles on amendments (e.g. lime), and erosion (Lal 2007). progressive individuals, e.g. “Pioneers of Agronomists have developed recommended Alternative Energy,” which makes real the management practices (RMPs) that increase soil sometimes illusive vision of how the world can quality and in doing so reduce net carbon adapt to and mitigate climate change. On the emissions and increase crop yield. RMPs are: no- other hand, the magazine touts corn ethanol as a till farming, incorporation of forages into the

4 EALLONDARDO MITIGATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 prospective mitigation solution, but the scientific problem in which potential providers will not evidence (e.g. Adler et al. 2007) does not support invest in hydrogen if potential consumers can not this position. The magazine lists 51 actions be identified and consumers will not purchase a individuals can take and communicates the fuel cell vehicle if the fuel is not reliable and effectiveness and cost of each action in simple widely available (Difiglio and Gielen 2007). diagrammatic terms. Lacking from this magazine Overcoming “chicken or the egg” type problems is more emphasis on forcing politicians to take will be an ideal opportunity for government up the climate change issue in large measure. intervention. Government spurred hydrogen use Voting for leaders who will be active on climate for mass transit/shipping would establish the issues is an important mitigation activity that infrastructural framework that consumers expect. individuals can perform. Difiglio and Gielen (2007) report that the relative mitigation cost of utilizing fuel cell vehicles CONSIDERATIONS FOR POLICYMAKERS decreases as total driving time increases, The risk of inaction on climate change, therefore the most effective initial use of which briefly stated amounts to increased stress hydrogen technologies would be in mass to hundred of millions of humans (IPCC 2007b) transit/shipping applications. outweighs the cost of action. The IPCC (2007c) Carbon certification systems states that the cost of stabilizing atmospheric CO2 at approximately double pre-industrial One of the key issues arising from the levels will range from 0.2-2.5% of global GDP. biofuels, conservation tillage, and CCS Upfront costs of implementing infrastructural components of Pacala and Socolow (2004) is changes will be almost completely recouped over that a certification system for carbon long term increases in efficiency. When sequestration is needed to set standards, assess economic models assume that current energy results, and provide an adaptive framework if market conditions are non-optimal (e.g. that standards are not being met. For example, three subsidies obscure real competitive interactions issues in regards to soil C sequestration are that: between commodities), GDP gains are predicted 1) Soil C eventually saturates if models assume that mitigation solutions improve market efficiencies (IPCC 2007c). In 2) Increasing global temperatures may reduce other words, there is a good overall chance for soil carbon storage money to be made on carbon mitigation if 3) As agriculture moves north in adapting to competitive markets are allowed to determine climate change, additional carbon may be which mitigation technologies are best and that volatilized from previously untilled they result in increases in energy efficiency and grounds productivity. Policy makers should also recognize that The biggest economic potentials exist in the soil C sequestration is not immediate and occurs building sector, followed by energy supply and over a roughly 40 year window. However, that tied for third are agriculture and industry (IPCC lag may be balanced by the fact that RMPs 2007c). In the building sector, 30% of projected generally mean less energy intensive approaches carbon emissions can be avoided through simple, which will also reduce C emissions through money-saving energy efficiency options e.g. reduced machinery and labor time (Rosenzweig more efficient lighting, heating and cooling and Tubiello 2007). systems; improved insulation; solar heating). The potential for profitable solutions for people, CITED REFERENCES WITH ABSTRACTS businesses and governments increases as oil price increases, and a multi-greenhouse gas mitigation approach tends to make conversion Adler, P.R., S.J. Del Grosso, W.J. Parton. less costly (IPCC 2007c). In other words, focus 2007. Life-cycle assessment of net greenhouse- on the low hanging fruit. gas flux for bioenergy cropping systems. Ecological Applications 17: 675-691. Hydrogen energy—where government Abstract: Bioenergy cropping systems could help intervention may be useful offset greenhouse gas emissions, but quantifying Overall, the combined risks associated with that offset is complex. Bioenergy crops offset production, distribution and end-use of hydrogen carbon dioxide emissions by converting has lead to the so-called “chicken or the egg” atmospheric CO2 to organic C in crop biomass

5 EALLONDARDO MITIGATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 and soil, but they also emit nitrous oxide and increase our understanding in those risks. Risks vary in their effects on soil oxidation of methane. caused by a failure in surface installations are Growing the crops requires energy (e.g., to understood and can be minimised by risk operate farm machinery, produce inputs such as abatement technologies and safety measures. The fertilizer) and so does converting the harvested risks caused by underground CO2 storage (CO2 product to usable fuels (feedstock conversion and CH4 leakage, seismicity, ground movement efficiency). The objective of this study was to and brine displacement) are less well understood. quantify all these factors to determine the net Main R&D objective is to determine the effect of several bioenergy cropping systems on processes controlling leakage through/along greenhouse-gas (GHG) emissions. We used the wells, faults and fractures to assess leakage rates DAYCENT biogeochemistry model to assess and to assess the effects on (marine) ecosystems. soil GHG fluxes and biomass yields for corn, Although R&D activities currently being soybean, alfalfa, hybrid poplar, reed canarygrass, undertaken are working on these issues, it is and switchgrass as bioenergy crops in expected that further demonstration projects and Pennsylvania, USA. DAYCENT results were experimental work is needed to provide data for combined with estimates of fossil fuels used to more thorough risk assessment. provide farm inputs and operate agricultural Difiglio, C., and D. Gielen. 2007. machinery and fossil-fuel offsets from biomass Hydrogen and transportation: alternative yields to calculate net GHG fluxes for each scenarios. Mitigation and Adaptation Strategies cropping system considered. Displaced fossil for Global Change 12: 387-405. fuel was the largest GHG sink, followed by soil carbon sequestration. N2O emissions were the Abstract: If hydrogen (H2) is to significantly largest GHG source. All cropping systems reduce greenhouse gas emissions and oil use, it considered provided net GHG sinks, even when needs to displace conventional transport fuels soil C was assumed to reach a new steady state and be produced in ways that do not generate and C sequestration in soil was not counted. significant greenhouse gas emissions. This paper Hybrid poplar and switchgrass provided the analyses alternative ways H2 can be produced, largest net GHG sinks, .200 g CO2e-C/m2/yr1 transported and used to achieve these goals. for biomass conversion to ethanol, and .400 g Several H2 scenarios are developed and CO2e-C/m2/yr1 for biomass gasification for compared to each other. In addition, other electricity generation. Compared with the life technology options to achieve these goals are cycle of gasoline and diesel, ethanol and analyzed. A full fuel cycle analysis is used to biodiesel from corn rotations reduced GHG compare the energy use and carbon (C) emissions by 40%, reed canarygrass by ;85%, emissions of different fuel and vehicle strategies. and switchgrass and hybrid poplar by 115%. Fuel and vehicle costs are presented as well as cost-effectiveness estimates. Lowest hydrogen Cleveland, C.J., R. Costanza, C.A.S. Hall, fuel costs are achieved using fossil fuels with and R. Kaufman. 1984. Energy and the U.S. carbon capture and storage. The fuel supply cost economy: a biophysical perspective. Science 225: for a H2 fuel cell car would be close to those for 890-897. an advanced gasoline car, once a large-scale Damen, K., A. Faaij, and W. Turkenburg. supply system has been established. Biomass, 2006. Health, safety and environmental risks of wind, nuclear and solar sources are estimated to underground CO2 storage—overview of be considerably more expensive. However fuel mechanisms and current knowledge. Climate cells cost much more than combustion engines. Change 74: 289-318. When vehicle costs are considered, climate policy incentives are probably insufficient to Abstract: CO2 capture and storage (CCS) in achieve a switch to H2. The carbon dioxide geological reservoirs may be part of a strategy to (CO2) mitigation cost would amount to several reduce global anthropogenic CO2 emissions. hundred US$ per ton of CO2. Energy security Insight in the risks associated with underground goals and the eventual need to stabilize CO2 storage is needed to ensure that it can be greenhouse gas concentrations could be applied as safe and effective greenhouse sufficient. Nonetheless, substantial development mitigation option. This paper aims to give an of related technologies, such as C capture and overview of the current (gaps in) knowledge of storage will be needed. Significant H2 use will risks associated with underground CO2 storage also require substantial market intervention and research areas that need to be addressed to during a transition period when there are too few

6 EALLONDARDO MITIGATION FOR 797 CLIMATE CHANGE EFFECTS ON NATURAL RESOURCES FALL 2007 vehicles to motivate widely available H2 about 10,000 years ago. Historic emission of soil refueling. C is estimated at 78 ± 12 Pg out of the total terrestrial emission of 136 ± 55 Pg, and post- Dixon, R.K. 2007. Advancing towards a industrial fossil fuel emission of 270 ± 30 Pg. hydrogen energy economy: status, opportunities Most soils in agricultural ecosystems have lost and barriers. Mitigation and Adaptation 50 to 75% of their antecedent soil C pool, with Strategies for Global Change 12: 325-341. the magnitude of loss ranging from 30 to 60 Mg Goldstein, J. 1999. International relations. C/ha. The depletion of soil organic carbon (SOC) Longman: New York, NY. 672 pp. pool is exacerbated by soil drainage, plowing, removal of crop residue, biomass burning, IPCC. 2005. Carbon dioxide storage and subsistence or low-input agriculture, and soil capture. Bert Metz, Ogunlade Davidson, degradation by erosion and other processes. The Heleen de Coninck, Manuela Loos and Leo magnitude of soil C depletion is high in coarse- Meyer (Eds.) Cambridge University Press, UK. textured soils (e.g., sandy texture, excessive pp 431. internal drainage, low activity clays and poor aggregation), prone to soil erosion and other IPCC. 2007a. Summary for policymakers. degradative processes. Thus, most agricultural In: cClimate change 2007: the physical science soils contain soil C pool below their ecological basis. Contribution of working group I to the potential. Adoption of recommend management fourth assessment report of the practices (e.g., no-till farming with crop residue Intergovernmental Panel on Climate Change mulch, incorporation of forages in the rotation [Solomon, S., D. Qin, M. Manning, Z. Chen, M. cycle, maintaining a positive nutrient balance, Marquis, K.B. Averyt, M.Tignor and H.L. Miller use of manure and other biosolids), conversion (eds.)]. Cambridge University Press, Cambridge, of agriculturally marginal soils to a perennial United Kingdom and New York, NY, USA. land use, and restoration of degraded soils and IPCC. 2007b. Summary for policymakers. wetlands can enhance the SOC pool. Cultivation In: climate change 2007: impacts, adaptation of peatlands and harvesting of peatland moss and vulnerability. Contribution of working group must be strongly discouraged, and restoration of II to the fourth assessment report of the degraded soils and ecosystems encouraged Intergovernmental Panel on Climate Change, especially in developing countries. The rate of M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. SOC sequestration is 300 to 500 Kg C/ha/yr van der Linden and C.E. Hanson, Eds., under intensive agricultural practices, and 0.8 to Cambridge University Press, Cambridge, UK, 7- 1.0 Mg/ha/yr through restoration of wetlands. In 22. soils with severe depletion of SOC pool, the rate of SOC sequestration with adoption of IPCC. 2007c. Summary for policymakers. restorative measures which add a considerable In: climate change 2007: mitigation. amount of biomass to the soil, and irrigated Contribution of working group III to the fourth farming may be 1.0 to 1.5 Mg/ha/yr. Principal assessment report of the Intergovernmental Panel mechanisms of soil C sequestration include on Climate Change [B. Metz, O.R. Davidson, aggregation, high humification rate of biosolids P.R. Bosch, R. Dave, L.A. Meyer (eds)], applied to soil, deep transfer into the sub-soil Cambridge University Press, Cambridge, United horizons, formation of secondary carbonates and Kingdom and New York, NY, USA. leaching of bicarbonates into the ground water. Kintish, K. 2007a. Making dirty coal plants The rate of formation of secondary carbonates cleaner. Science 317: 184-186. may be 10 to 15 Kg/ha/yr, and the rate of leaching of bicarbonates with good quality Kintish, K. 2007b. Report backs more irrigation water may be 0.25 to 1.0 Mg C/ha/yr. projects to sequester CO2 from coal. Science The global potential of soil C sequestration is 0.6 315:1481. to 1.2 Pg C/yr which can off-set about 15% of Lal, R. 2007. Carbon management in the fossil fuel emissions. agricultural soils. Mitigation and Adaptation Myhre, G., and A. Myhre. 2003. Strategies for Global Change 12: 303-322. Uncertainties in radiative forcing due to surface Abstract: World soils have been a major source albedo changes caused by land-use changes. of enrichment of atmospheric concentration of Journal of Climate 16: 1511–1524. CO2 ever since the dawn of settled agriculture,

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Pacala, S., and R. Socolow. 2004. Stabilization wedges: solving the climate problem for the next 50 years with current technologies. Science 305: 968-972. Abstract: Humanity already possesses the fundamental scientific, technical, and industrial know-how to solve the carbon and climate problem for the next half-century. A portfolio of technologies now exists to meet the world's energy needs over the next 50 years and limit atmospheric CO2 to a trajectory that avoids a doubling of the preindustrial concentration. Every element in this portfolio has passed beyond the laboratory bench and demonstration project; many are already implemented somewhere at full industrial scale. Although no element is a credible candidate for doing the entire job (or even half the job) by itself, the portfolio as a whole is large enough that not every element has to be used. Rau, G.H., and K. Caldiera. 2007. Coal’s Future: clearing the air. Science 316: 691. Raymond, P.A., and J.J. Cole. 2003 Increase in the Export of Alkalinity from North America's Largest River. Science 301: 88-91. Righelato, R., and D.V. Spracklen. 2007. Carbon mitigation by biofuels of by saving and restoring forests? Science 317: 902. Rosenzweig, C., and F.N. Tubiello. 2007. Adaptation and mitigation strategies in agriculture: an analysis of potential synergies. Mitigation and Adaptation Strategies for Global Change 12: 855-873. Sheppard, M.C., and R.H. Socolow. 2007. Sustaining fossil fuel use in a carbon-constrained world by rapid commercialization of carbon capture and sequestration. American Institute of Chemical Engineers 53: 3022-3028. U.S. Census Bureau. 2006. World population information. http://www.census.gov/ ipc/www/idb/worldpopinfo.html. U.S. Census Bureau, Washington, DC.

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