Trashing EPA's Endangerment Finding Would Be Tough

In a Washington where climate change is again a hot debate topic, there is one bulwark of climate science that may be impossible for critics to tear down.

The endangerment finding is perhaps the most forceful presence of climate science in President Trump's Washington, one backed by a Supreme Court decision and arguably harder to take on than any other climate issue the administration has fought.

Although U.S. EPA under Scott Pruitt has targeted climate regulations at a rapid pace, the endangerment finding — EPA's 2009 determination that greenhouse gases threaten public health and welfare — is a building block upon which they could be reconstructed in a post-Trump era.

The EPA boss hasn't publicly committed to targeting the finding, but he's under pressure from conservative think tanks and Trump transition team officials to take it on.  In his speeches Pruitt has focused on the uncertainties inherent in climate science to resist regulations.

But that approach won't be enough to roll back the endangerment finding, said Dan Esty, director of the Yale Center for Environmental Law & Policy.

"The ongoing uncertainties don't undo the danger that's posed by the buildup of greenhouse gases in the atmosphere," he said.

For about 200 pages, the endangerment finding lays out science explaining how the buildup in greenhouse gases is hurting humanity.

Without government regulation restricting emissions, the report concludes, humanity is very likely to suffer harm.  It points to dire problems like increased heat waves, forest fires, and droughts.  Those changes and others are the direct result of human activity over the last few centuries, the report says.  Warming has risen at an unprecedented rate over several decades.

"Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations," the report says.  "Climate model simulations suggest natural forcing alone (i.e., changes in solar irradiance) cannot explain the observed warming."

Conservatives have pushed the Trump administration to challenge the endangerment finding because it is the building block for the swath of Obama-era EPA climate rules.  Recently, Pruitt has signaled that he is open to the idea, though he has not said whether his agency will take it on or punt to Congress.  Some see his proposed climate science review, known as a red-team, blue-team approach, as a prelude to challenging the finding.

Any attempt to weaken the endangerment finding stands to become one of the biggest battles over the environment in a Washington that's already embroiled in fights over health care, tax reform, and investigations into election meddling by Russia.

And winning is no sure thing.

A legal victory over the endangerment finding would take a mountain of research, observers say.  The Obama-era determination is based on more than 100 peer-reviewed scientific studies.  It draws on research from the Intergovernmental Panel on Climate Change and the National Academy of Sciences.  It has already withstood legal attacks and been upheld by the courts.

How would Pruitt do it?
It's unclear whether Pruitt will attempt to unravel the finding, but if he does, it would probably be by focusing on the uncertainties inherent in all scientific exercises, observers say.

Read more at Trashing EPA's Endangerment Finding Would Be Tough