Millions of Americans suffer from the harmful effects of ground-level ozone pollution, which exacerbates lung diseases such as asthma and can cause breathing difficulties even in healthy individuals. The result is more time spent in hospital emergency rooms, as well as additional sick days and even premature deaths. These health impacts not only involve suffering; they are also costly, constituting a significant drag on the U.S. economy. While power plants and cars are among the main sources of ozone-forming pollutants (the chemical precursors to ozone), ozone’s formation is dependent on temperature, among other conditions. As a result, climate change has the potential to increase ozone pollution—and its health and economic burdens—across large parts of the country both now and in the future.
This report from the Union of Concerned Scientists combines projections of future climate-induced temperature increases with findings on the relationship between ozone concentrations and temperature to illustrate a potential “climate penalty on ozone.”1 This penalty demonstrates how higher temperatures could increase ozone pollution above current levels, assuming that emissions of ozone-precursor pollutants remain constant.
We analyzed this climate penalty’s health consequences expected in 2020 and 2050, including increases in respiratory symptoms, hospital visits for the young and old, lost school days, and premature mortality, for most of the continental United States. We also projected the economic costs of these health impacts in 2020.