Agency believes greenhouse gases harm public health

---

The U.S. Environmental Protection Agency last month issued a proposed finding that emissions of six specific greenhouse gases contribute to air pollution that may endanger public health or welfare within the meaning of the Clean Air Act. The action followed a U.S. Supreme Court decision that ordered a scientific review of the issue.

By a 5-4 decision in April 2007, the court also rejected the U.S. Environmental Protection Agency’s argument that Congress’ delegation of authority for fuel economy to the U.S. Department of Transportation prevented EPA from regulating motor vehicle emissions of carbon dioxide. The fact “that DOT sets mileage standards in no way licenses EPA to shirk its environmental responsibilities,” the court said.

In response, EPA Administrator Lisa Jackson also is proposing to find that the combined emissions of carbon dioxide, methane, nitrous oxide and hydrofluorocarbons from new motor vehicles and new motor vehicle engines are contributing to the mix of greenhouse gases in the atmosphere and, therefore, to air pollution that endangers public health and welfare. The two other greenhouse gases included in the proposed finding – perfluorocarbons and sulfur hexafluoride – are not emitted by motor vehicles.

If finalized, EPA’s proposed findings could give the agency broad authority to regulate greenhouse gas emissions, including those from motor vehicles. EPA said the science shows that concentrations of these gases are at unprecedented levels as a result of human emissions and that these high levels are very likely the cause of the increase in average temperatures and other changes in our climate.

Climate change, in turn, affects human health in several ways, EPA says. One recent study concluded that climate change may lead to higher concentrations of ground-level ozone, a harmful pollutant. Other potential impacts may include increased drought, more 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, EPA concluded. In addition, climate change has national security implications due to destabilization resulting from scarce resources, such as water, the agency said.

The proposed finding does not include any proposed regulations. EPA said it would conduct an appropriate process and consider stakeholder input before taking steps to reduce greenhouse gases. The agency also reiterated President Obama’s preference for legislation to address greenhouse gases. EPA has scheduled public hearings this month on its proposed finding – May 18 in Arlington, Va., and May 21 in Seattle.

For more information, go to www.epa.gov/climatechange/endangerment.html. Comments and other information also are available at www.regulations.gov by searching EPA-HQ-OAR-2009-0171.