Greenhouse gases threaten public health, says EPA

April 29, 2009

The Environmental Protection Agency (EPA) has proposed to find that six greenhouse gases—including some emitted by general aviation aircraft—threaten public health and welfare. The agency did not propose any regulations on emitters of greenhouse gases, but the finding could be a preliminary step toward the eventual regulation of greenhouse gas emissions, including those from engines.

AOPA will file comments on the proposed finding and has commented on the issue in the past.

“Piston-powered aircraft account for approximately one-tenth of 1 percent of transportation greenhouse gas emissions,” said Craig Spence, AOPA vice president of regulatory affairs. Spence added that AOPA “will continue to urge the EPA to consider the cost burden and effect on aviation safety before imposing any emissions rules on the GA community.”

The proposed findings, published in the Federal Register April 24, could lay the groundwork for regulations similar to the ones that the agency explored last year in an advanced notice of proposed rulemaking. The notice seeks ways to regulate greenhouse gas emissions from many sources, including aircraft, under the Clean Air Act.

For any of those rules to be enacted, the EPA must first rule that the air pollutants in question “cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare”—a stipulation of the Clean Air Act that the Supreme Court ruled applies to greenhouse gases. As emitters of carbon dioxide, GA aircraft could eventually fall under the purview of EPA regulations under the Clean Air Act.

The proposed endangerment finding is based on scientific analysis of six gases, including carbon dioxide. According to the EPA, concentrations of these gases are at unprecedented levels as a result of human emissions, and those high levels likely contribute to climate change. The draft now enters the 60-day public comment period.

Legislative action could open another avenue for the oversight of greenhouse gas emissions. President Barack Obama and EPA Administrator Lisa Jackson have repeatedly indicated their preference for comprehensive legislation to address the issue of greenhouse gases.