Climate Matters: EPA to revoke landmark greenhouse gas finding

Less than five years after the country's most significant climate change law was enacted, the Environmental Protection Agency is moving to revoke a landmark finding on greenhouse gas emissions that forms the basis of much of the United States' current climate legislation.

EPA Administrator Lee Zeldin is expected to rescind the 2009 endangerment finding, which expanded the government's authority to regulate emissions from vehicles, manufacturing, and the oil and gas sector.

In 2007, the Supreme Court ruled in Massachusetts v. E.P.A. that the agency had the power to regulate greenhouse gases under the Clean Air Act of 1970. However, the justices demanded evidence that these gases harm human health.

Two years later, the EPA provided over 200 pages of scientific data outlining how rising greenhouse gas emissions affect the atmosphere—causing longer droughts, more intense heat waves, and rising sea levels, all of which contribute to increased injury and death.

We're still emitting greenhouse gases at record levels. "Global concentrations of greenhouse gases are higher than ever before, and continue to rise," says Lauren Casey, a meteorologist at Climate Central.

Although the United States has reduced its greenhouse gas emissions over the past few decades, these effects will be felt for generations. Only about half of greenhouse gases are directly absorbed by oceans and plants, while a third remains in the atmosphere for sometimes centuries.

Reducing further emissions can help lessen the worsening effects of climate change. "By moving toward clean energy sources and away from fossil fuels, we can significantly cut our greenhouse gas emissions," Lauren states. "This climate solution is essential to slow worsening climate impacts like extreme weather and sea level rise."

The EPA’s latest action is unlikely to challenge the scientific consensus on climate change directly. Instead, it focuses on the agency's authority to regulate emissions, as the Trump administration seeks to push back against perceived government overreach.

The administration is also moving swiftly to allow more time for legal processes to unfold in the courts. If the issue returns to the Supreme Court, it will face three conservative justices who originally dissented from the 2007 ruling.