The United States Environmental Protection Agency’s decision to repeal limits on greenhouse gas emissions will have detrimental impacts, according to Penn climate experts.
The EPA announcement, released last month, reverses regulations on power plant emissions made under the Biden administration. The repeal is yet another refusal by 1968 Wharton graduate and President Donald Trump to address climate change, an issue he called the “greatest con job ever perpetrated on the world.”
“The Trump Administration and the MAGA movement have turned their backs on science,” Legal Studies and Business Ethics professor Eric Orts wrote in a statement, calling the decision “devastating.”
The administration’s “denial” of climate science is the “worst setback for making climate progress in history,” Orts added.
Political Science professor Scott Moore wrote in a statement that the repeal “signals a general retreat from any federal action to limit the contribution of US industry to climate change.”
Earth and Environmental Studies professor Michael Mann shared Moore’s criticism.
These decisions have “blunted” the country’s progress in moving toward renewable energy, Mann wrote in a statement. He cited how renewables accounted for roughly 88% of new electrical generating capacity added in the United States last year, which outperformed the 85% achieved by the rest of the world.
The Trump administration’s move to block critical clean energy infrastructure and “double down” on policies incentivizing fossil fuel extraction allows foreign competitors like China to lead the global renewable energy revolution, Mann stated.
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He added that these developments have also “eroded” the scientific community’s confidence in the administration’s science and research policies.
Mann took part in a 2025 open letter signed by nearly 2,000 scientists and engineers that denounced the administration’s “assault” on science through mass federal layoffs, funding freezes, and the cancellation of vital grants — including at Penn.
“The U.S. is falling behind the rest of the world on the climate issue; this failure will come back to haunt us,” Orts wrote. “Many more people will likely die from climate-related causes as a result. Likely millions if present policy continues.”
Orts blames “the greed of Big Oil and Gas” for “driving us off the climate cliff.”
He also wrote that artificial intelligence has become a focus for corporations “allied” with the technology due to its “vast energy needs.”
Penn Carey Law professor of Energy Policy Shelley Welton wrote in a statement that the administration’s repeal could not have “come at a worse time for the power sector,” given the rise of data centers, which require rapid expansion of energy generation infrastructure.
Welton added that the energy sources used to fulfill this “ballooning demand” will have “reverberating effects on the climate for decades to come.”
Citing both the upcoming midterms in November and the 2028 general election, Mann wrote that voting for politicians who will “support rather than hinder our progress” is one way for people to make a difference.
“This can be reversed in two years if voters elect a president who actually cares about the livability of our planet,” he wrote.
On Oct. 1, a coalition of state and city officials, including Pennsylvania Gov. Josh Shapiro, sued the Trump administration over the regulation repeal.
“Dismantling these protections is a betrayal of American families, and the stakes are too high to allow this administration to once again put profits over people,” New York Attorney General Letitia James said in her announcement of the lawsuit.
The EPA’s decision follows its earlier repeal of the 2009 Greenhouse Gas Endangerment Finding in February, reversing the conclusion that greenhouse gases endangered public health, and therefore removing the prerequisite for implementing emissions standards for vehicles and other sectors.
“We know how to solve the climate crisis technologically,” Orts wrote, citing how solar and wind sources are now often cheaper than oil and gas prices. “It is a large engineering problem, but not an impossible one.”
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Staff reporter Sameeksha Panda covers science and health and can be reached at panda@thedp.com. At Penn, she studies chemistry.
