A major shift in federal climate policy is underway as former President Donald Trump prepares to roll back the 2009 “endangerment finding,” a landmark Environmental Protection Agency determination that greenhouse gases, including carbon dioxide, pose a threat to public health and welfare.
The finding, issued during the Obama administration, has served as the legal foundation for more than a decade of federal climate regulations, including emissions standards for vehicles and power plants. Supporters have called it a necessary response to climate change. Critics argue it unleashed sweeping regulatory authority based on flawed science.
Steve Milloy, founder of JunkScience.com and a longtime critic of climate policy, said the endangerment finding marked the beginning of what he describes as a regulatory “assault” on fossil fuels and traditional energy sources.
“The 2009 ruling enabled the EPA to regulate carbon dioxide as a pollutant,” Milloy said, noting that the move coincided with tighter emissions rules and policies that he argues contributed to coal plant closures and financial losses in the automotive sector tied to electric vehicle mandates.
Milloy contends that carbon dioxide is not a harmful pollutant in the traditional sense and disputes claims that rising CO₂ levels are driving catastrophic climate change. He also argues that higher carbon dioxide concentrations have coincided with increased agricultural productivity, helping support a growing global population.
If repealed, the endangerment finding would face immediate legal challenges. The original authority for regulating greenhouse gases was reinforced by a 2007 Supreme Court decision in Massachusetts v. EPA, which held that greenhouse gases could be regulated under the Clean Air Act if found to endanger public health. Milloy said more recent Supreme Court rulings narrowing federal agency authority could bolster efforts to reverse the policy.
While the federal rollback would significantly affect national emissions rules, states like Illinois may not follow suit. Illinois has adopted aggressive clean energy targets, including phasing out fossil fuel power generation by 2045. Governor J.B. Pritzker has championed policies promoting renewable energy and emissions reductions, even as critics warn about grid reliability and rising electricity costs.
Energy demand is expected to increase in the coming years, driven in part by expanding data centers and efforts to reindustrialize portions of the U.S. economy. Milloy argues that wind and solar power alone cannot meet those demands and that continued reliance on oil, natural gas, and coal will remain essential.
Debate over environmental priorities extends beyond climate change. In Chicago, officials continue grappling with the replacement of hundreds of thousands of aging lead service lines. While lead exposure is widely recognized as harmful at certain levels, Milloy said that low concentrations of lead in drinking water have not been conclusively linked to widespread health damage in modern contexts, a view that contrasts with prevailing public health guidance.
The broader conversation reflects a deep divide over environmental policy, scientific consensus, and economic tradeoffs. Proponents of climate regulation argue that carbon emissions contribute to global warming and extreme weather, requiring urgent action. Opponents say policies built on the endangerment finding have raised energy costs, strained infrastructure, and relied on exaggerated claims.
The repeal effort signals that climate regulation will remain a central political battleground. Whether the rollback survives legal scrutiny could determine the trajectory of federal environmental policy for years to come.