How will Wisconsin's forests and wetlands respond to climate change? April 2013 Prof. Ankur Desai University of Wisconsin-Madison Image: NASA MODIS IPCC Technical Summary IPCC NORTHERN HEMISPHERE TEMPERATURE RECONSTRUCTIONS Figure TS.20. (Top) Records of Northern Hemisphere temperature variation during the last 1300 years with 12 reconstructions using multiple climate proxy records shown in colour and instrumental records shown in black. (Middle and Bottom) Locations of temperature- sensitive proxy records with data back to AD 1000 and AD 1500 (tree rings: brown triangles; boreholes: black circles; ice core/ice boreholes: blue stars; other records including low-resolution records: purple squares). Data sources are given in Table 6.1, Figure 6.10 and are discussed in Chapter 6. {Figures 6.10 and 6.11} 55 • Global change science research involves: – Analysis of observations of air, water, land, humans over space and time – Lab and field experiments of these quantities – Theory and math about the physics, chemistry, biology, geology, and economics of the Earth System – Computational simulation of various Earth system models to test hypotheses against observations – Synthesis, communication, and application of findings from all of the above • All require: – good questions, precise observations, and working in diverse teams! • Source: UCAR Quarterly, Summer 2007 http://www.iceuls.com/_photo/b.jpg CARBON Where Is The Carbon Going? Ecosystem Carbon Sink Houghton et al. (2007) 12 I. BUFFAM et al. Flux rates in Gg-C yr-1 Pool sizes in Gg-C Atmosphere Precip 12 Forest NEE Fossil fuels 994 Wetland NEE 154 GPP 3233, R 2238 124 CO2 evasion GPP 878, R 754 28 CH4 emission CH4 evasion 13 2 Wetland litter 1 Wetland runoff 21 Sed 22 Runoff Forest litter 34 2 Forest runoff Buffam et al., 2011 24 Forests: 64,000 Wetlands: 158,000 Surface Waters: 162,000 Fig. 2 Schematic showing the three major ecosystem types of the Northern Highlands Lake District (NHLD), along with best estimates of C flux rates and pool sizes. These estimates are associated with varying degrees of uncertainty (Tables 1–5). Forests make up 54% of the NHLD area, wetlands 28% (including 20% peatlands and 8% other wetlands), and lakes 13%. NEE, net ecosystem exchange; GPP, gross primary production; R, respiration. age of wetlands relative to upland forests (Table 2). Lake patches of C evasion, with smaller lakes having the CO2 evasion contributes about 3% of the regional total highest evasion rates (Fig. 3c). net exchange. Precipitation flux into and hydrologic flux out of the NHLD are on the order of 1% and 3%, respectively, of the regional total net exchange. Discussion The mismatch between pool sizes and current rates points to widely disparate mean C turnover times Implications of magnitude and spatial variability of C among wetlands, lakes, and forests of the region. pools and fluxes Assuming current rates are representative of long-term rates, the estimated average time required to build up By constructing a C budget we incorporated surface each major regional C pool was 65 years for forest, 1775 freshwaters, wetlands, and upland forests into a single years for peat wetlands, and 7364 years for lake sedi- framework. This framework establishes a context for C ments. cycling research in this and other surface-water rich regions. An integrated view like this is needed to target research and management strategies in a parsimonious Spatial distribution of C pools and fluxes on the landscape way. Pools and fluxes of C were spatially heterogeneous at a We determined that the largest current-day annual range of spatial scales in the NHLD landscape. The land–atmosphere fluxes in the NHLD region are found most dense pools of C were peat in peatlands and in forests, which are aggrading. This rate is an order of sediments in lakes (Fig. 3b). Patches of relatively young magnitude higher than surface–atmosphere exchange coniferous forest gave by far the greatest local rates of in wetlands or surface waters (Fig. 2, Table 2). Thus the influx of C into the land surface, while lakes gave rise to current behavior of the NHLD in terms of annual C r 2010 Blackwell Publishing Ltd, Global Change Biology, doi: 10.1111/j.1365-2486.2010.02313.x CLIMATE Svante Arrhenius 19 February Born 1859(1859-02-19) Vik, Sweden 2 October 1927(1927-10-02) Died (aged 68) Stockholm, Sweden Nationality Swedish Fields Physics, chemistry Royal Institute of Institutions Technology Uppsala University To explain the ice age, Arrhenius estimated that Alma mater Stockholm University halving of CO2 would decrease temperatures by Per Teodor Cleve, Doctoral advisor Erik Edlund 4 - 5 °C (Celsius) and a doubling of CO2 would Doctoral students Oskar Benjamin Klein cause a temperature rise of 5 - 6 °C. In his 1906 Arrhenius equation publication, Arrhenius adjusted the value Theory of ionic Known for dissociation downwards to 1.6 °C (including water vapour Acid-base theory feedback: 2.1 °C). Recent (2007) estimates from Nobel Prize for Notable awards Chemistry (1903) IPCC say this value (the Climate sensitivity) is Franklin Medal (1920 likely to be between 2 and 4.5 °C. Arrhenius expected CO2 doubling to take about 3000 years; it is now estimated in most scenarios to take about a century. IPCC Technical Summary IPCC NORTHERN HEMISPHERE TEMPERATURE RECONSTRUCTIONS Figure TS.20. (Top) Records of Northern Hemisphere temperature variation during the last 1300 years with 12 reconstructions using multiple climate proxy records shown in colour and instrumental records shown in black. (Middle and Bottom) Locations of temperature- sensitive proxy records with data back to AD 1000 and AD 1500 (tree rings: brown triangles; boreholes: black circles; ice core/ice boreholes: blue stars; other records including low-resolution records: purple squares). Data sources are given in Table 6.1, Figure 6.10 and are discussed in Chapter 6. {Figures 6.10 and 6.11} 55 • Reportaddednewindicatorstobetterunderstandchangesin theglobalclimate • Samebottomlineconclusion–climatecontinuestochange BAMS State of the Climate 2011 Globalaveragesurfacetemperaturewashigherthanthe 1981to2010average • Septemberseaiceextentwas 2nd smallestsincethesatellite Carbon dioxideUpper Ocean Heat Content Global Temperature erabegan Sept. 2011 • Oldice(4–5years)reached recordlow:81%belowaverage July2012 StateoftheClimatein2011 3 March:whenmaximumiceextentoccurs September:whenminimumiceextentoccurs Carbondioxide • Greenlandicesheet:Aboveaverageair Fourdatasetsshowglobalsurface Globallytemperaturesaveragedandcarbondecliningdioxidealbedo Globallyaveragedheatstoredin concentrationsintheatmosphere thetop2,300feetoftheoceans temperaturescontinuetorise; (reFlectivity)causedextrememelting surpassed390partspermillionforthe wasthehighestsincerecords temperaturehasincreasedatarate firstandtime.masslossin2011 beganin1993. ofabout0.31ºFperdecadesince 1980. July2012 StateoftheClimatein2011 10 July2012 StateoftheClimatein2011 6 2011: La Niña in the eastern equatorial Pacific kept global surface temperatures cooler during the year compared with the record warmth of 2010, but still remained above the average of the past 30 years Long-term trend: Temperatures at the Earths surface and lower atmosphere continue to warm, while the stratosphere continues to cool July2012 StateoftheClimatein2011 7 Summary for Policymakers Geographical pattern of surface warming Figure SPM.6. Projected surface temperature changes for the late 21st century (2090-2099). The map shows the multi-AOGCM average projec- th tion for the A1B SRES scenario.2090 Temperatures (IPCC are 4 relative Assessment) to the period 1980-1999. {Figure 3.2} Some systems, sectors and regions are likely to be espe- ! Africa, because of low adaptive capacity and projected cially affected by climate change.12 {3.3.3} climate change impacts ! Systems and sectors: {3.3.3} small islands, where there is high exposure of population and infrastructure to projected climate change impacts ! particular ecosystems: ! Asian and African megadeltas, due to large populations -terrestrial: tundra, boreal forest and mountain regions and high exposure to sea level rise, storm surges and river because of sensitivity to warming; mediterranean-type flooding. ecosystems because of reduction in rainfall; and tropi- cal rainforests where precipitation declines Within other areas, even those with high incomes, some -coastal: mangroves and salt marshes, due to multiple people (such as the poor, young children and the elderly) can stresses be particularly at risk, and also some areas and some activi- -marine: coral reefs due to multiple stresses; the sea ice ties. {3.3.3} biome because of sensitivity to warming ! water resources in some dry regions at mid-latitudes13 and Ocean acidification in the dry tropics, due to changes in rainfall and evapo- The uptake of anthropogenic carbon since 1750 has led to transpiration, and in areas dependent on snow and ice melt the ocean becoming more acidic with an average decrease in ! agriculture in low latitudes, due to reduced water avail- pH of 0.1 units. Increasing atmospheric CO concentrations ability 2 lead to further acidification. Projections based on SRES sce- ! low-lying coastal systems, due to threat of sea level rise narios give a reduction in average global surface ocean pH of and increased risk from extreme weather events between 0.14 and 0.35 units over the 21st century. While the ef- ! human health in populations with low adaptive capacity. fects of observed ocean acidification on the marine biosphere are Regions: {3.3.3}