Forests are not protected under current air quality standards, court decides

September 9, 2019

Human health standard upheld, rebuffing challenges that it is overprotective

A decision by the U.S. Court of Appeals for the District of Columbia Circuit in late August 2019 affirms AMC and others’ claims that the 2015 ozone standard left forests under-protected. The court sent portions of the rule back to the EPA where they must revisit their approach in meeting the Clean Air Act obligation to protect trees and vegetation from injury and loss of growth caused by ozone pollution.

“The Court’s decision importantly recognizes that for forests to be healthy we need strong clean air protections. For decades AMC has been working to improve these standards. We’re pleased by this decision reinforcing the role the Clean Air Act has in protecting ecological health and ecosystem services,” said John Judge, President & CEO of AMC.

“The Clean Air Act requires EPA to set standards that protect forests against damage from smog. EPA didn’t do that here. It must go back and fix its mistakes so forested landscapes can thrive,” said Seth Johnson, the Earthjustice attorney who argued the case. “Unfortunately, the Court also said the ozone rules we have are enough to protect public health, even though these standards allow levels of smog EPA agrees are harmful. But this isn’t the end of the road. We’ll keep fighting for this vital health protection to be as effective as it needs to be.”

“Ozone pollution can cause substantial damage to trees and plants, stunting their growth, making them much more susceptible to disease and drought, and causing yellowing or mottled leaves. We need to address the specific impacts of ozone pollution on trees and plants to truly protect the outdoor environments where we go to hike and seek refuge,” said AMC staff Scientist, Georgia Murray. “The Court’s decision clearly upholds science as the necessary basis for EPA’s decisions.”

Less favorable was the Court’s decision that the health standard met the legal requirements to protect public health. Based on a growing body of science, AMC and others argue that the ozone human health standards are not stringent enough. When ozone is elevated EPA warns people to limit outdoor activities because exercising and working outside increase your risk for health impacts. AMC’s own research testing the lungs of Mt. Washington, NH, hikers shows that hikers lung function declines as ozone levels increase.

AMC has been tracking the ozone concentrations in the White Mountain National Forest for over 3 decades. Ozone formed near the ground in urban and industrial areas can be transported to rural mountains and reach unhealthy levels for breathing. While ozone has declined in some areas of the Northeast, including the NH mountains, recent levels are worsening in some places. The American Lung Association’s 2019 State of the Air report found that more than four in 10 (41.1 percent) of people in the United States live in areas with unhealthy levels of ozone pollution.

The Court’s decision results from a suit brought by Earthjustice on behalf of the Sierra Club, Physicians for Social Responsibility, National Parks Conservation Association, Appalachian Mountain Club, and WE ACT for Environmental Justice. Earthjustice also represented the American Lung Association, the Natural Resources Defense Council, Sierra Club, and Physicians for Social Responsibility in opposing polluters’ challenge to the standards.

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G. Murray

Conservation and Nature Notes blogger Georgia Murray has been AMC's Air Quality Staff Scientist since 2000. She has an M.S. degree in Earth Sciences from the University of New Hampshire and currently oversees the AMC's air quality and climate monitoring programs.