After a thorough scientific review ordered in 2007 by the U.S. Supreme Court, EPA issued a proposed finding last Friday (April 17) that greenhouse gases contribute to air pollution that may endanger public health or welfare, according to an EPA press statement.

The proposed finding, which now moves to a public comment period, identified six greenhouse 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,” said Administrator Lisa P. Jackson in a prepared statement. “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 what the agency describes as “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. Says EPA: “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, according to EPA. 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.

In proposing the finding, Administrator 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, according to the EPA press statetment.

In addition to threatening human health, the analysis finds that climate change also has serious national security implications, according to the agency. Consistent with this proposed finding, in 2007, 11 retired U.S. generals and admirals signed a report from the Center for a New American Security stating that climate change “presents significant national security challenges for the United States.” Escalating violence in destabilized regions can be incited and fomented by an increasing scarcity of resources – including water. This lack of resources, driven by climate change patterns, then drives massive migration to more stabilized regions of the world.

The proposed endangerment finding now enters the public comment period, which is the next step in the deliberative process EPA must undertake before issuing final findings.

The proposed finding 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 this issue and create the framework for a clean energy economy, according to the EPA news statement.

U.S. Senator Barbara Boxer (D-CA), Chairman of the Senate Committee on Environment and Public Works, released the following additional statement on EPA's proposed endangerment finding and the threat posed by global warming emissions.

Senator Boxer said: "EPA, through its scientists, has given us a warning that global warming pollution is a clear, present and future danger to America's families. If Congress does not act to pass legislation, then I will call on EPA to take all steps authorized by law to protect our families."

Senator James Inhofe (R-Okla.), ranking member on the Senate Environment and Public Works Committee, said that the EPA’s proposed endangerment finding will unleash a torrent of regulations that will destroy jobs, harm consumers, and extend the agency's reach into every corner of American life. Despite enormous expense and hardship for the American economy, these regulations will have virtually no effect on climate change, he said in a press statement.

"Today's action by the EPA is the beginning of a regulatory barrage that will destroy jobs, raise energy prices for consumers, and undermine America's global competitiveness," Senator Inhofe said. "It now appears EPA's regulatory reach will find its way into schools, hospitals, assisted living facilities, and just about any activity that meets minimum thresholds in the Clean Air Act. Rep. John Dingell was right: the endangerment finding will produce a ‘glorious mess.' "It's worth noting that the solution to this ‘glorious mess' is not for Congress to pass cap-and-trade legislation, which replaces one very bad approach with another. Congress should pass a simple, narrowly-targeted bill that stops EPA in its tracks."