title: Improved attribution of climate forcing to emissions.
abstract: Evaluating multicomponent climate change mitigation strategies requires knowledge of the diverse direct and indirect effects of emissions. Methane, ozone, and aerosols are linked through atmospheric chemistry so that emissions of a single pollutant can affect several species. We calculated atmospheric composition changes, historical radiative forcing, and forcing per unit of emission due to aerosol and tropospheric ozone precursor emissions in a coupled composition-climate model. We found that gas-aerosol interactions substantially alter the relative importance of the various emissions. In particular, methane emissions have a larger impact than that used in current carbon-trading schemes or in the Kyoto Protocol. Thus, assessments of multigas mitigation policies, as well as any separate efforts to mitigate warming from short-lived pollutants, should include gas-aerosol interactions.
authors.affiliation: NASA Goddard Institute for Space Studies and Columbia University, New York, NY 10025, USA. drew.t.shindell@nasa.gov
authors.forename: Drew T
authors.initials: DT
authors.lastname: Shindell
authors.forename: Greg
authors.initials: G
authors.lastname: Faluvegi
authors.forename: Dorothy M
authors.initials: DM
authors.lastname: Koch
authors.forename: Gavin A
authors.initials: GA
authors.lastname: Schmidt
authors.forename: Nadine
authors.initials: N
authors.lastname: Unger
authors.forename: Susanne E
authors.initials: SE
authors.lastname: Bauer