[20081017]RS22970_二氧化碳排放量增长是否比预期更快？.pdf

1 For explanation of greenhouse gases and their influence on the Earths climate, see CRS ReportRL33849, Climate Change: Science and Policy Implications, by Jane A. Leggett. Order Code RS22970October 17, 2008Are Carbon Dioxide Emissions Rising MoreRapidly Than Expected?Jane A. LeggettSpecialist in Environmental and Energy PolicyResources, Science and Industry DivisionJeffrey LoganSpecialist in Energy PolicyResources, Science and Industry DivisionSummaryAt least one recent report and numerous news articles suggest that carbon dioxide(CO2) emissions are rising more rapidly than expected. This contention is often madeby comparing recent emissions estimates with the greenhouse gas (GHG) scenariospublished by the Intergovernmental Panel on Climate Change (IPCC) in 2000. WhileCO2 emissions associated with human activities continue to rise and may be worthyof alarm because of their influence on climate change any short-term comparisonsbetween actual emissions and IPCC scenarios miss the mark. First, the IPCC scenariosexplicitly are not predictions. Second, the IPCC scenarios are meant to representdifferent possible GHG trajectories over many decades, and represent smooth emissionspaths ave