'Holy Smoke: immediate global warming mitigation via smog control'
Nadine Unger

Air pollutants in smog influence global climate in complex ways. Ozone and black 
carbon lead to warming whereas sulfate and indirect aerosol effects on clouds 
lead to cooling. At present air quality regulations are made without 
consideration of their effect on climate. The short lifetimes of air pollutants 
mean that changes in precursor emissions have the potential to substantially 
affect near-term climate. However, ozone and aerosol radiative forcing (RF) 
depends on the location and source type of the precursor emissions. We apply the 
NASA GISS atmospheric composition and climate model to quantify the net 
contribution of air pollutants from 6 different economic sectors from each of 7 
regions to RF in order that more effective emissions control policy (beneficial 
to both climate and air quality) may be developed. The model includes full 
coupling between gas and aerosol chemistry and interactive aerosol-cloud climate 
effects. Across-the-board emissions reductions from transportation in Europe and 
North America and domestic biofuel in East Asia offer the greatest potential for 
substantial, simultaneous improvement in local air quality and near-term 
mitigation of global climate change via short-lived species. Conversely, 
reductions in power and industry emissions have the potential to accelerate 
near-term warming, though they would improve air quality and have a long-term 
cooling effect on climate. Conversion to an electric vehicle (EV) fleet in the 
United States could reduce RF in the near and long terms, and prevent around 
3000 premature human mortalities per year. A worldwide EV fleet yields a net 
total RF of -0.14 Wm-2 and would have a discernable impact on global warming as 
part of a multi-pronged strategy.