On April 17, 2009, the Environmental Protection Agency announced its finding that greenhouse gases contribute to air pollution and may endanger public health or welfare. This new action was the direct result of a scientific review originally ordered in 2007 by the United States Supreme Court.
The so-called "Endangerment Finding" states that: "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". The EPA Administrator, Lisa P. Jackson, has publicly commented that: "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".
On April 2, 2007, in Massachusetts v. EPA, 549 U.S. 497 (2007), the Supreme Court found that greenhouse gases are air pollutants covered by the Clean Air Act. The Court held that the EPA Administrator must determine whether or not emissions of greenhouse gases from new motor vehicles cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare, or whether the science is too uncertain to make a reasoned decision.
Specifically the EPA Administrator has found that:
- The current and projected concentrations of the mix of six key greenhouse gases—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)—in the atmosphere threaten the public health and welfare of current and future generations. This is referred to as the endangerment finding.
- The combined emissions of CO2, CH4, N2O, and HFCs from new motor vehicles and motor vehicle engines contribute to the atmospheric concentrations of these key greenhouse gases and hence to the threat of climate change. This is referred to as the cause or contribute finding.
For more information visit the EPA´s website dedicated to the Endangerment Finding: EPA Endangerment Information