EPA Reports on Climate

Enlarge Image Image Gallery Air pollution in action. iStockphoto.com/ideeone

Washington, D.C. –After a thorough scientific review ordered in 2007 by the U.S. Supreme Court, the Environmental Protection Agency recently issued a proposed finding that greenhouse gases contribute to air pollution that may endanger public health or welfare.

The agency also released a report on the potential impacts of climate change on regional U.S. air quality. The information contained in the report will enhance the United States’ ability as a nation to protect air quality and human health.

The proposed finding on greenhouse gases, which now moves to a public comment period, identified six such gases that pose a potential threat.

 “This finding confirms that greenhouse gas pollution is a serious problem now and for future generations. Fortunately, it follows President Obama’s call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation,” EPA Administrator Lisa P. Jackson says. “This pollution problem has a solution – one that will create millions of green jobs and end our country’s dependence on foreign oil.”

As the proposed endangerment finding states, “In both magnitude and probability, climate change is an enormous problem. The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act.”

EPA’s proposed endangerment finding is based on rigorous, peer-reviewed scientific analysis of six gases – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – that have been the subject of intensive analysis by scientists around the world. The science clearly shows that concentrations of these gases are at unprecedented levels as a result of human emissions, and these high levels are very likely the cause of the increase in average temperatures and other changes in our climate.

The scientific analysis also confirms that climate change impacts human health in several ways. Findings from a recent EPA study titled “Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground-Level Ozone,” for example, suggest that climate change may lead to higher concentrations of ground-level ozone, a harmful pollutant. Additional impacts of climate change include, but are not limited to: increased drought; more heavy downpours and flooding; more frequent and intense heat waves and wildfires; greater sea level rise; more intense storms; and harm to water resources, agriculture, wildlife and ecosystems.

The report concludes that there is a potential for climate change to make ozone pollution worse in some regions and that future ozone management decisions may need to account for the possible impacts of climate change.

Climate change has the potential to produce increases in ground-level ozone in many regions. Ground-level ozone is formed in the presence of sunlight by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOCs), which are emitted from sources like motor vehicles and industrial facilities. Climate change also could increase the number of days with weather conditions conducive to forming ozone, potentially causing air quality alerts earlier in the spring and later in the fall.