The human health co-benefits of air quality improvements associated with climate change mitigation

Abstract

Fossil fuel combustion processes that generate greenhouse gases (GHG) also emit and or cause the creation of other harmful air pollutants. Thus, while policies designed to avert the course of climate change would eventually result in direct human health benefits from lessened global temperature changes and associated impacts, they would also bring much more immediate ancillary human health co- benefits from the associated reduced ground-level air pollution in the short term. Several measures aimed at reducing GHG emissions, notably the reduced use of fossil fuels such as coal, can also improve local air quality, most notably particulate matter (PM) and ozone (O3 ) air pollution. Further, whereas the benefits from climate change mitigation would materialize far in the future, these co-benefits, or ancillary benefits, would provide much more immediate "return on investment" in climate change mitigation. Thus, as detailed below, the near-term human health co-benefits of climate mitigation (e.g., fossil fuel emission reductions) may provide the most economically compelling justification for immediate action towards climate change mitigation. Here we discuss the health impacts of PM and ozone, two key air pollutants that have substantial impacts on human health and that are likely to be reduced by policies aimed at controlling GHG emissions.