A groundbreaking new report from the National Academies of Science, Engineering, and Medicine has unequivocally declared that the evidence connecting increasing emissions to detrimental human health impacts is beyond any scientific doubt.
This report arrives at a crucial moment, as the Environmental Protection Agency embarks on a fresh attempt to undo a pivotal scientific finding that currently empowers the federal government to regulate greenhouse gas emissions.
The Trump administration is keen to repeal the 2009 ‘endangerment finding,’ a critical ruling that established carbon dioxide, methane, and other greenhouse gases as threats to human health, thus allowing their regulation under the Clean Air Act.
Given that this finding is the foundation for numerous environmental regulations, some conservative voices view its repeal as a strategic move to dismantle a host of climate policies simultaneously. In July, E.P.A. administrator Lee Zeldin heralded the proposed revocation as “the largest deregulatory action in the history of the United States.”
To illustrate, imagine the endangerment finding as a foundational tablecloth, with regulations on power plant and vehicle emissions as the vital items resting upon it. The E.P.A.’s proposed action could, in effect, sweep away all these protections in one fell swoop.
A key argument from the Trump administration for overturning the endangerment finding centers on the claim that scientific understanding has evolved since 2009, suggesting that the evidence no longer justifies regulations on emissions from vehicles and power facilities.
However, as observed by Brad Plumer, the recent National Academies report presents a starkly different conclusion: the scientific evidence affirming the danger of increasing greenhouse gas levels to human health has become even more robust since the initial finding.
Why is the E.P.A. tasked with regulating greenhouse gases?
Back in 2007, a Supreme Court decision mandated that the Clean Air Act requires the E.P.A. to control pollutants that negatively impact human health by contributing to global warming. Consequently, the agency issued the endangerment finding for greenhouse gases in 2009.
Following this, the agency promptly introduced new regulations, establishing limits on greenhouse gas emissions from various sources, including automobiles, power plants, and industrial facilities.
Though the Trump administration contemplated rescinding the endangerment finding during its initial term, the effort ultimately did not proceed.
Despite facing over 100 lawsuits, the finding has consistently been affirmed by appellate courts. Even business organizations that once vehemently opposed the rule, like the Chamber of Commerce, appeared to accept it as “settled law” as recently as January.
So, what’s behind the Trump administration’s renewed challenge now?
Brigit Hirsch, an E.P.A. spokeswoman, stated in an email, “In the 16 years since the endangerment finding was established, many of the highly pessimistic forecasts and assumptions the E.P.A. relied on have not unfolded as predicted.” She also noted that the agency is currently accepting public feedback on the proposed repeal until Monday.
Any attempt to repeal this finding would undoubtedly face further legal battles. Some observers believe a more calculated motive is at play: Sharmila Murthy, a professor of law and public policy at Northeastern University, suggests the administration sees a strong chance of success given recent Supreme Court rulings that have considerably limited agency authority.
Conflicting Views: The Battle Over Climate Science
The E.P.A.’s rationale for repealing the endangerment finding partly stems from a July report commissioned by the Energy Department, which controversially downplayed the severity of climate change. This report was compiled by five scientists known for questioning climate impact, and subsequently, over 85 other scientists sharply criticized it for numerous inaccuracies and misrepresentations.
In sharp contrast, the National Academies report underscores that the evidence linking rising emissions to serious public health risks is now more compelling than ever.
According to some experts who spoke with Plumer, the Trump administration’s strategy to challenge the foundational science of the endangerment finding could prove to be a significant miscalculation, potentially backfiring.
The E.P.A. is legally obligated to consider all public comments when making its final decision. Should it fail to sufficiently address the extensive evidence connecting emissions to adverse health effects, the agency could expose itself to considerable legal weaknesses.
What Happens if the Endangerment Finding is Overturned?
Should the regulations based on the endangerment finding be reversed, U.S. emissions from power plants and vehicles would still decline, but at a significantly slower pace than if current limits were maintained.
A study by the Natural Resources Defense Council projects a 40 percent reduction in U.S. vehicle emissions by 2050. However, if the E.P.A.’s vehicle emission rules are eliminated, this reduction would plummet to just 10 percent.
Kathy Harris, the council’s director of clean vehicles, emphasized, “That represents an enormous disparity for the primary contributor to greenhouse gas emissions in the U.S.”
The power sector faces a comparable outlook: existing regulations aim for a 41 percent emissions cut by 2032, but without the endangerment finding’s foundational rules, this reduction would only reach 20 percent.
Our oceans
Corals won’t survive a warmer planet, a new study finds
If global temperatures continue rising, virtually all the corals in the Atlantic Ocean will stop growing and could succumb to erosion by the end of the century, a new study finds.
The analysis of over 400 existing coral reefs across the Atlantic Ocean estimates that more than 70 percent of the region’s reefs will begin dying by 2040 even under optimistic climate warming scenarios.
And if the planet exceeds 2 degrees Celsius of warming above preindustrial temperatures by the end of the century, 99 percent of corals in the region would meet this fate.
The implications are grave. Corals act as the fundamental building blocks of reefs, providing habitat for thousands of species of fish and other marine life. — Sachi Kitajima Mulkey
Read more.
In one number
An estimated 70,000 deaths per year
If the planet continues to warm at its current rate, exposure to wildfire smoke will kill an estimated 70,000 Americans each year by 2050, according to new research.
The results are some of the strongest evidence yet that climate change endangers people in the United States, said Marshall Burke, an environmental economist at Stanford University who contributed to the study. For Americans, “the impacts are much larger than anything else that has been measured,” Dr. Burke said.
Wildfire smoke, intensified by rising temperatures, is on track to become one of America’s deadliest climate disasters, causing as many as two million deaths over the next three decades, the analysis found. One public health expert called the report a “wake-up call.” — Sachi Kitajima Mulkey and Harry Stevens
Read more.
In their own words
“When we don’t measure things, it makes it much harder to claim that there is a problem and that the government has some kind of responsibility to help alleviate it.”
That’s from Sarah Pralle, an associate professor of political science at Syracuse University, who spoke to Maxine Joselow for an article about the Trump administration’s moves to stop collecting some forms of climate data.
The administration has moved to stop getting planet-warming emissions data from industrial plants, and various agencies have stoped collecting other types of climate data that have been seen as crucial to understanding a dangerously warming planet.
Read more.
More climate news from around the web:
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“China’s vast, uncontrolled squid-fishing effort in the unregulated waters off South America is putting marine ecosystems at risk of depletion and leaving crew members vulnerable to physical abuse, overwork and even death,” The Washington Post writes, citing a new report by the Environmental Justice Foundation.
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Carbon dioxide emissions from India’s power sector fell by 1 percent in the first half of 2025 compared with the same period last year, according to an analysis by Carbon Brief. That’s only the second decline in nearly 50 years, the analysis found.