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List of Abstracts 62of the biological system to temperature changes. Our work examines the relationships between theseprocesses and provides estimates of the effect of these feedbacks on future emissions. If these ideas areextended to natural wetlands the positive feedback effect can add to current calculations of future methaneconcentrations.P-Chemistry Climate.7 ID:4581 15:35Sea of Scenarios: what do we know about projected methane emissions?Elaine Matthews 1 , Ellen Baum 21 NASA Goddard Institute for Space Studies2 Clean Air Task ForceContact: ematthews@giss.nasa.govClimate-chemistry model experiments for the 21st century have relied almost exclusively on a restricted setof methane (and other) emission projections primarily from economic-centered models. In baselinescenarios, emissions commonly rise continuously for several decades while those reflecting implementationof mitigation technologies often exhibit deep emission reductions by 2030 and later. Lack of transparencymakes it extremely difficult to determine drivers of the emissions and which technology mixes underpin thehigh levels of mitigation reported. In contrast to the baseline-and-mitigation approach, the IPCC SRESfamily of projections encompassed multiple economic, demographic, environmental etc. trajectoriesquantified by several models. However, the wide range of SRES future emissions is equally difficult tounderstand or evaluate. Lastly, the primary focus of most emission projections has been on carbon dioxide,with later and modest inclusion of methane.The largely black-box nature of emission projections used in climate-chemistry experiments and policyanalyses has received almost no attention despite the substantial influence exerted by these inputs. This lackof transparency makes assessing the likelihood, or even plausibility, of projected emissions all butimpossible. Thus modeled climate-chemistry interactions with future emissions are more like sensitivityexperiments than predictions, while policy discussions lack the practical understanding needed to decide onmitigation strategies. Plans for the next IPCC assessment include additional scenario development. Wepropose further analyzing existing projections and mitigation options with the goal of reducing, notincreasing, the suite of scenarios for climate studies.We have developed new, transparent methane projections for the major methane sources. We report on workto assess the plausibility of assumptions and data underlying the new and existing projections that includesanalysis against historical trends, and development and testing of plausibility criteria.P-Chemistry Climate.8 ID:4403 15:35Ozone and Methane budgets in the ACCMIP modelsDavid Stevenson 1 , ACCMIP Modellers 21 University of Edinburgh2 VariousContact: dstevens@staffmail.ed.ac.ukI will present a preliminary analysis of ozone and methane budgets from the ACCMIP model integrations.These span from pre-industrial times up to the present-day and then follow a variety of future scenarios (theRCPs, or representative concentration pathways) agreed for the forthcoming IPCC AR5. Several modelshave submitted (and will be submitting) results, allowing inter-model uncertainty to be quantified. FindingsiCACGP-IGAC 2010 12 July, 2010