Skip to main content

Radiative forcing and climate response to projected 21st century aerosol decreases

Author(s): Westervelt, DM; Horowitz, LW; Naik, V; Mauzerall, Denise L

To refer to this page use:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorWestervelt, DM-
dc.contributor.authorHorowitz, LW-
dc.contributor.authorNaik, V-
dc.contributor.authorMauzerall, Denise L-
dc.identifier.citationWestervelt, DM, Horowitz, LW, Naik, V, Mauzerall, DL. (2015). Radiative forcing and climate response to projected 21st century aerosol decreases. Atmospheric Chemistry and Physics Discussions, 15 (6), 9293 - 9353. doi:10.5194/acpd-15-9293-2015en_US
dc.description.abstract© Author(s) 2015. It is widely expected that global emissions of atmospheric aerosols and their precursors will decrease strongly throughout the remainder of the 21st century, due to emission reduction policies enacted to protect human health. For instance, global emissions of aerosols and their precursors are projected to decrease by as much as 80% by the year 2100, according to the four Representative Concentration Pathway (RCP) scenarios. The removal of aerosols will cause unintended climate consequences, including an unmasking of global warming from long-lived greenhouse gases. We use the Geophysical Fluid Dynamics Laboratory Climate Model version 3 (GFDL CM3) to simulate future climate over the 21st century with and without the aerosol emission changes projected by each of the RCPs in order to isolate the radiative forcing and climate response resulting from the aerosol reductions. We find that the projected global radiative forcing and climate response due to aerosol decreases do not vary significantly across the four RCPs by 2100, although there is some mid-century variation, especially in cloud droplet effective radius, that closely follows the RCP emissions and energy consumption projections. Up to 1 W mg-2 of radiative forcing may be unmasked globally from 2005 to 2100 due to reductions in aerosol and precursor emissions, leading to average global temperature increases up to 1 K and global precipitation rate increases up to 0.09 mm dg-1. Regionally and locally, climate impacts can be much larger, with a 2.1 K warming projected over China, Japan, and Korea due to the reduced aerosol emissions in RCP8.5, as well as nearly a 0.2 mm dg-1 precipitation increase, a 7 g mg-2 LWP decrease, and a 2 μm increase in cloud droplet effective radius. Future aerosol decreases could be responsible for 30-40% of total climate warming by 2100 in East Asia, even under the high greenhouse gas emissions scenario (RCP8.5). The expected unmasking of global warming caused by aerosol reductions will require more aggressive greenhouse gas mitigation policies than anticipated in order to meet desired climate targets.en_US
dc.format.extent1 - 23en_US
dc.relation.ispartofAtmospheric Chemistry and Physics Discussionsen_US
dc.rightsFinal published version. This is an open access article.en_US
dc.titleRadiative forcing and climate response to projected 21st century aerosol decreasesen_US
dc.typeJournal Articleen_US

Files in This Item:
File Description SizeFormat 
ACP_Radiative forcing.pdf6.52 MBAdobe PDFView/Download

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.