EPA Issues Proposed Endangerment Finding for Greenhouse Gases; Proposed Cause or Contribute Finding Identifies Motor Vehicles as Contributing Source
After a thorough scientific review ordered in 2007 by the US Supreme Court, the US Environmental Protection Agency (EPA) issued a proposal with two distinct findings regarding greenhouse gases. (Earlier post.) The endangerment finding proposes 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. The issuance of an endangerment finding enables the regulation of greenhouse gases under the Clean Air Act.
The proposed cause or contribute finding concludes that that 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. Combined with the endangerment finding, this enables the regulation of greenhouse gas emissions from motor vehicles under the Clean Air Act.
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.—Proposed Endangerment Finding
The proposed findings now enter the public comment period, which is the next step in the deliberative process EPA must undertake before issuing final findings. The proposal does not include any proposed regulations. Before taking any steps to reduce greenhouse gases under the Clean Air Act, EPA would conduct an appropriate process and consider stakeholder input.
Notwithstanding this required regulatory process, both President Obama and Administrator Jackson have repeatedly indicated their preference for comprehensive legislation to address the issue.
There are two public hearings scheduled for this proposed finding: 18 May at the EPA Potomac Yard Conference Center, Arlington, VA; and 21 May at the Bell Harbor International Conference Center in Seattle, WA.
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 US 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.
Climate change has the potential to produce increases in ground-level ozone in many regions, according to the report. 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.
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.
In proposing the finding, EPA Administrator Lisa Jackson also took into account the disproportionate impact climate change has on the health of certain segments of the population, such as the poor, the very young, the elderly, those already in poor health, the disabled, those living alone and/or indigenous populations dependent on one or a few resources.