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A Publication of the Climate Institute | Protecting the balance between climate and life on Earth Special Edition: Understanding Methane’s Potential to Amplify or Reduce Arctic Climate Change CLIMATE INSTITUTE Summer 2015 Volume 27, No. 1 Climate Alert A MESSAGE FROM THE CHIEF SCIENTIST Methane—the Other Carbon-Containing Greenhouse Gas Commentary by we first need to find an alternative nations would by now be well along Michael MacCracken means for securing the services that in cutting their emissions. Unfortu- fossil energy has been providing and nately, that has not been the case. In With good reason, more, given the continuing growth in the search for emissions pathways significant attention the global population. that could contribute to a near-term is being devoted to The global average temperature is slowing of the overall greenhouse sharply cutting emis- now up about 0.9°C over its prein- warming influence, we now have to sions of carbon diox- dustrial average and projected to rise go back and separate out the distinct ide (CO2). In general, emissions result further with the onset of the strong roles and lifetimes of each individual from combustion of coal, oil, and nat- El Niño that appears to be emerging. greenhouse gas and type of warming ural gas (together, fossil fuels) to pro- Furthermore, the rate of sea level or cooling aerosol. Continuing to use vide energy and, somewhat less im- rise is accelerating due both to addi- the hundred-year Global Warming portantly, from clearing of land for tional melting of the Greenland and Potential (GWP-100) would be ob- agriculture, wood products, and com- Antarctic ice sheets and greater up- scuring potentially effective policy munities. Using fossil fuels in particu- take. Coupled with the likelihood and options. lar transfers carbon that has been intensity of extreme weather increas- Recognition of this emerged almost tied up underground for tens of mil- ing, the rate the world’s nations are a decade ago in leading elements of lions of years to the coupled atmos- proposing to cut emissions is so mod- the scientific community at the NASA phere-upper ocean-living biosphere est that it will not lead to a slowing of Goddard Institute for Space Studies system, which leads to an uptick in the rate of warming until well into and a bit later in our studies here at the atmospheric concentration. As a the second half of this century. By the Climate Institute (see http:// significant fraction of this will persist that time, the increase in global aver- www.climate.org/topics/climate- for millennia, and somewhat less for age temperature is projected to be change/maccracken-proposal-north- much longer, its implications are con- over 2°C and still rising. This means south-framework.html). The benefits cerning. that we will be headed to well above of a plausible set of actions were fur- Just this March, the CO2 concentra- the level of temperature increase ther studied in detail in a 2011 inter- tion at the Mauna Loa Observatory in that international leaders have national assessment sponsored by Hawai’i reached 400 ppm, up over agreed will cause, based on solid sci- the United Nations Environment Pro- 40% above its preindustrial baseline. entific results, quite disruptive im- gramme and World Meteorological Stabilizing the atmospheric concen- pacts on the environment and socie- Organization (published as Shindell, tration, much less bringing it back ty. et al., Science, volume 335, pages down, will require essentially cutting So what, if anything, can be done? 183-189, 2012). These studies all emissions to zero. The longer this To simplify the analyses for the nego- made it very clear that achievable takes, the higher the elevated CO2 tiation process, the warming effects reductions in emissions of methane, concentration will be, the longer it of the emissions of non-CO2 species black carbon and the precursors of will persist, and the greater the cli- have been combined together to cre- tropospheric ozone, all species that mate change and associated impacts ate a CO2-equivalent (CO2e) concen- have a relatively short atmospheric will be. On first sight, the intensifying tration based on the relative lifetime, could reduce the projected impacts would seem to be large strengths of their warming influ- warming by ~0.5°C, which is about enough to merit strong near-term ences, integrated over a 100-year half of the projected warming from steps to cut emissions. However, the period. This approach to approxi- the present out to 2050. This would fact that fossil fuels provide roughly mating how climate models treat the be a very important contribution to 80% of the energy providing food, full chemistry and warming influ- slowing the pace of global warming energy, and other services for the 7 ences of each individual gas was while at the same time providing a billion people on the planet means adopted a quarter of a century ago, number of benefits for human that the use of fossil fuels cannot when there were expectations that health, energy efficiency, and cleaner simply be ended. In order to do that, Page 2 Climate Institute | www.climate.org Climate Alert Volume 27, No. 1 air. Recognizing the importance of activities. Some include tightening up author Brooke Labonte, a Climate In- such efforts, Secretary of State Hillary emissions from oil and gas operations stitute Arctic Intern, is a recent gradu- Clinton with UNEP and representa- (as EPA is working on with new rules), ate of Ryerson University in Toronto, capturing emissions from waste dis- tives of five other nations launched Ontario, where she studied Geograph- the Climate and Clean Air Coalition posal and sewage sites, and reducing ic Analysis and Environment and Ur- (http://www.ccacoalition.org) emissions from the agricultural sector in 2012; it is now a growing interna- (e.g., from feed lots, chicken and pig ban Sustainability. Their article high- tional effort to pursue reductions in operations, etc.). Even taking these lights the importance of the methane the emissions of these species. actions, the atmospheric methane cycle in present and future climate For the past several years, the Cli- concentration seems likely to remain and the many uncertainties in our un- mate Institute has been encouraging roughly 1000 ppb above its preindus- derstanding of this cycle, especially efforts that will cut emissions of trial level of about 750 ppb, and the role of methanotrophs, and rec- these short-lived species. The most could become even higher if thawing ommends research to fill these gaps in far-reaching has been our contribu- of permafrost and clathrates leads to tion to the development of a new an increase in natural emissions. With our understanding. methodology for life cycle analysis the per mass effectiveness of me- (see thane as a global warming agent be- http://www.leonardoacademy.org/ ing as much as a factor of 100 times programs/standards/life-cycle.html). that for CO2 over a 20-year period, This methodology would accurately exploring possible options for pulling account for the effectiveness of the methane concentration down is cutting emissions of methane, black worthy of exploration. As a basis for carbon, and other species contrib- such analysis, it is vital to understand uting to climate change in limiting the natural sources and sinks of me- global warming, as well as more fully thane and the processes and factors treat related environmental and that influence them. health-related influences. We also This is what Lyle Zimmerman and published a special edition of Climate Brooke Labonte cover in the accom- Alert (http://www.climate.org/ panying article in this issue. A biolo- publications/Climate%20Alerts/ gist with undergraduate and masters Autumn2009.html) on black carbon, degrees from Stanford and a Ph. D and coordinated with Rotec on their efforts to install black carbon controls from MIT, Dr. Zimmerman estab- on jeepneys in Manila and trucks in lished and led his own research group Xian. We furthermore participated in at the UK MRC National Institute for the development by the international Medical Research in London. An Arc- Gold Standard Foundation in the es- tic Fellow with the Climate Institute, tablishment of a methodology for he has led the Climate Institute’s accrediting emissions reductions study of the methane cycle and espe- from clean stove replacement pro- grams in India and other nations. cially the role of methanotrophs With this issue of Climate Alert we (methane consuming bacteria and focus our attention on methane. archaea) in limiting damage from There are a number of very important both human-generated and naturally and effective actions that can be tak- occurring methane emissions. His co- en to limit emissions from human Page 3 Climate Institute | [email protected] Climate Alert CLIMATE CHANGE AND THE MICROBIAL METHANE BANQUET By Lyle Zimmerman & Brooke Labonte ly important microorganisms. 2010 saw an eye-opening demon- Methane is terrifying not only due stration of the microbial response to to increasing industrial and agricul- methane in the Gulf of Mexico. The tural emissions, which have nearly largest oil spill in history occurred tripled atmospheric methane con- about 1500 meters below the surface centration since 1750, but also be- as the Deepwater Horizon drilling rig cause of the potential for enormous blew out. In addition to oil, about a Methane is a powerful green- releases from natural carbon reser- half million tons of natural gas, most- house gas, second only to CO2 in voirs beneath Arctic permafrost ly methane, was released on the sea- importance, with increasing pro- where warming is occurring most floor. If that methane had all bubbled duction from human activities as quickly.
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