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Aerosol contribution to the rapid warming of near‐term climate under RCP 2.6
Author(s) -
Chalmers N.,
Highwood E. J.,
Hawkins E.,
Sutton R.,
Wilcox L. J.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052848
Subject(s) - environmental science , aerosol , climatology , atmospheric sciences , anomaly (physics) , radiative forcing , forcing (mathematics) , shortwave radiation , climate model , subtropics , northern hemisphere , climate change , greenhouse gas , meteorology , radiation , geology , geography , oceanography , physics , condensed matter physics , quantum mechanics , fishery , biology
The importance of aerosol emissions for near term climate projections is investigated by analysing simulations with the HadGEM2‐ES model under two different emissions scenarios: RCP2.6 and RCP4.5. It is shown that the near term warming projected under RCP2.6 is greater than under RCP4.5, even though the greenhouse gas forcing is lower. Rapid and substantial reductions in sulphate aerosol emissions due to a reduction of coal burning in RCP2.6 lead to a reduction in the negative shortwave forcing due to aerosol direct and indirect effects. Indirect effects play an important role over the northern hemisphere oceans, especially the subtropical northeastern Pacific where an anomaly of 5–10 Wm −2 develops. The pattern of surface temperature change is consistent with the expected response to this surface radiation anomaly, whilst also exhibiting features that reflect redistribution of energy, and feedbacks, within the climate system. These results demonstrate the importance of aerosol emissions as a key source of uncertainty in near term projections of global and regional climate.