HR: 10:20h
AN: GC12A-01    [Abstracts]
TI: From Human Activities to Climate Change: Uncertainties in the Causal Chain
AU: * Prather, M J
EM: mprather@uci.edu
AF: UC Irvine, Earth System Science Dept 3329 Croul Hall, Irvine, CA 92697-3100, United States
AU: GROUP, M
EM: mprather@uci.edu
AB: While formal attribution of observed climate change to the overall increase in atmospheric greenhouse gases has been made, the relationship between specific human activities and their consequent levels of climate change has not been followed with the same level of scientific scrutiny. This paper tracks the causal chain from human activities to greenhouse gas emissions as reported under the UNFCCC, to changing atmospheric composition, to radiative forcing, and finally to climate change, propagating a scientific assessment of the uncertainty in climate change caused by those activities. Greenhouse gas emissions for the years 1990 through 2002 are available from most of the Annex-I countries, and we follow the effect these have on atmospheric abundances and global mean surface temperature at the end of the period. A new evaluation of the total aerosol radiative forcing is derived. The probable temperature change in year 2003 that can be attributed to these Annex-I emissions, +0.106 (-0.029,+0.034), is less than half of that due to global emissions for the same period and is asymmetric with a longer tail for larger temperature changes. This study is the collective work of a group of scientists (MATCH) responding to the UNFCCC parties request for scientific evaluation of attributable climate change for possible use in post-Kyoto negotiations.
DE: 0365 Troposphere: composition and chemistry
DE: 0485 Science policy (6620)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1630 Impacts of global change (1225)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting