National Academies’ climate report supports endangerment finding, contradicting EPA

The scientific evidence that greenhouse gas (GHG) emissions cause harm to human health and welfare “is beyond scientific dispute,” the National Academies of Sciences, Engineering, and Medicine (NASEM) says in a report released Wednesday, directly contradicting statements from the US Environmental Protection Agency.

The EPA recently proposed (PDF) to rescind its endangerment finding, a 2009 report that says GHGs endanger human health and welfare and that forms the scientific and legal basis for regulating GHG emissions under the Clean Air Act. In speaking about the EPA’s proposal, Administrator Lee Zeldin said that evidence of this harm has weakened or been contradicted based on observations since 2009.

But according to the NASEM report released yesterday, there’s more evidence of harm now than in 2009, and the evidence is stronger. “Much of the understanding of climate change that was uncertain or tentative in 2009 is now resolved and new threats have been identified,” the report says.

When asked about the scientific discrepancies between the NASEM report and Zeldin’s comments, EPA press secretary Brigit Hirsch responded that GHG regulations during the administrations of Barack Obama and Joe Biden cost trillions. “As we saw in the 16 intervening years since the Endangerment Finding was made, many of the extremely pessimistic predictions and assumptions EPA relied upon have not materialized as expected,” she says in an email. Hirsch did not respond to C&EN’s repeated attempts at clarification of her statements.

In its proposal to rescind the endangerment finding, the EPA based its scientific justification largely on a US Department of Energy (DOE) report developed by the Climate Working Group and released July 29. Brought together by DOE Secretary Chris Wright, the group’s members were five known climate change denialists, including John Christy and Steve Koonin. The DOE report has been highly criticized by climate scientists, who say that its conclusions “are either misleading or fundamentally incorrect.” The DOE report amassed over 59,500 comments during its public comment period, which ended Sept. 2.

Instead of reviewing the DOE report, NASEM announced on Aug. 7 that it would conduct an independent, self-funded report on the climate science published since the endangerment finding’s release in 2009. “The study was undertaken with the ultimate aim of informing the EPA, following its call for public comments, as it considers the status of the endangerment finding,” Shirley Tilghman, professor emeritus in molecular biology at Princeton University and chair of the NASEM report committee, says in a statement. “We are hopeful that the evidence summarized here shows the strong base of scientific evidence available to inform sound decision-making.”

The group submitted the report as a public comment on the EPA’s proposal to rescind the endangerment finding. As of Sept. 18, the EPA’s proposal has elicited over 105,000 comments. The public comment period ends Sept. 22, and the EPA is scheduled to issue the final rule this month.

The NASEM finished its report in roughly the same amount of time as the Climate Working Group, using the same publicly available body of science, says Andy Miller, former senior science adviser for the EPA’s Office of Research and Development. And the difference in the reports is stark, he says. “In essence, the DOE report said there are some things [in the science] that are uncertain, therefore we don’t know enough to do anything,” Miller says. “Whereas the Academies essentially said we know a lot.”

“Perhaps the most important [thing] to note is that the [National Academy of Sciences] process that led to this Consensus Study Report involves an independent review by experts chosen for their technical expertise,” says Melissa Finucane, vice president of science and innovation at the environmental advocacy group the Union of Concerned Scientists. “This is the type of information that policymakers should rely on to make decisions that affect Americans’ health and prosperity.”

The Donald J. Trump administration has since disbanded the Climate Working Group in response to a lawsuit brought by the Union of Concerned Scientists and the Environmental Defense Fund (EDF). The groups claim that by not holding public meetings as it prepared its report, the Climate Working Group violated laws about transparency in federal advisory committees. On Sept. 17, a federal judge ruled that even though the Climate Working Group has been dissolved, the federal transparency laws still apply to the group and its report. Members of the group are continuing to work, the EDF says, citing a news report.

What the EPA will do with the NASEM report and the other comments refuting the proposal’s science is unclear, Miller says. “If EPA is going to reverse a decision that has been based on scientific evidence, then the evidence to reverse that decision needs to be at least as strong as that that was originally cited,” he says. That’s been the practice in government scientific decisions in the past, Miller says. “But who knows what’s going to happen now?”

The Business Council for Sustainable Energy, the Clean Energy Business Network, and the American Chemistry Council all declined to comment for this story. The US Chamber of Commerce did not reply to C&EN’s request for comment.