On February 12, 2026, President Donald Trump announced that the US Environmental Protection Agency (EPA) is reversing the legal finding it has relied on for nearly 20 years to limit heat-trapping pollution from vehicle tailpipes, oil refineries and factories. This action reverses a long-standing determination based on climate science, stripping the agency of its regulatory authority to control emissions.

In 2009, the EPA issued a comprehensive scientific “endangerment finding” that greenhouse gases (GHGs) pose a threat to public health and welfare. The agency prepared the document after thoroughly reviewing US and international peer-reviewed climate assessments in response to a US Supreme Court decision requiring review before regulating GHGs under the US Clean Air Act.

The present administration justifies its proposal by citing a new Department of Energy report that selectively ignores the extensive body of peer-reviewed research and instead relies on outdated and disproven claims. This illustrates another instance of strong climate change denial efforts. 

In the years following the EPA’s 2009 endangerment finding, federal action quickly turned the scientific decision into regulations. Starting in 2010, the administration and agencies established vehicle-emissions and fuel-efficiency standards. They used the Clean Air Act to reduce greenhouse gas emissions from power plants and other industrial sources. These efforts peaked in 2015 with the Clean Power Plan and a series of climate and mobile-source regulations, marking the most ambitious federal attempt to reduce US emissions.

The next three administrations alternated policies. Between 2017 and 2020, regulations were rolled back: the Clean Power Plan was targeted for repeal, the Affordable Clean Energy proposal was introduced and vehicle emissions targets were relaxed under the Safer, Affordable Fuel-Efficient Vehicles Rule (SAFE). Starting in 2021, the Biden administration worked to undo many of these rollbacks, restore stricter standards and reaffirm the scientific basis of the endangerment finding at the core of federal climate policy. Now, with the current US Presidency, there seems to be a trend to disconnect climate science from national environmental regulations. 

Economic claims vs. domestic reality: assessing fossil-fuel benefits

The current administration claims that, over generations, fossil fuels have saved millions of lives and lifted billions of people out of poverty worldwide. However, a more detailed analysis indicates this isn’t accurate for America since 1980.

In the US, although the average income of a US citizen was $57 per day, in 2023, an estimated 36.8 million Americans lived below the poverty line of $24.50 per day, according to the US Census Bureau. This results in an official poverty rate of over 11% of the total American population.

Poverty in the US is often linked to economic and social factors, including the lack of a strong social safety net and significant racial disparities. Since 1980, income inequality has been rising sharply. This trend results from political and economic shifts that seem to have disproportionately benefited the wealthiest. During this period, fiscal policies started to resemble favors to the wealthy, with tax cuts benefiting those already in advantageous positions.

Beyond social inequalities, the continued use of fossil fuels directly conflicts with the endangerment finding issued during President Barack Obama’s first term. However, the EPA now states that the decision “unreasonably analyzed the scientific record” and that its scientific basis was overly pessimistic and unsupported. Such an opinion blatantly contradicts the majority of climate science in the US and worldwide.

Science under siege: EPA, evidence and vulnerabilities

In a briefing with reporters last month ahead of the EPA’s decision, the president and CEO of the Natural Resources Defense Council (NRDC), Manish Bapna, called the expected repeal “the single biggest attack in US history on federal authority to tackle the climate crisis.” On the NRDC’s website, they explicitly say: “This decision is dangerous. It’s also illegal. We will see them in court, and we will win.”

The expectation of legal plaintiffs against the EPA’s “endangerment finding” relates to its very purpose and legal basis: Under the Clean Air Act (section 202[a]), the EPA determined whether GHGs from new motor vehicles “may reasonably be anticipated to endanger” public health or welfare. This followed the Supreme Court’s decision in Massachusetts v. EPA (2007), which required the EPA to make such a determination for GHGs if supported by science.

Climate science has always been based on peer-reviewed research, including work from the Intergovernmental Panel on Climate Change (IPCC) — the UN body established in 1988 to assess climate change —, the National Research Council, the US Global Change Research Program and other reputable organizations. These sources demonstrate that GHG emissions are driving climate change, leading to impacts such as rising temperatures and sea levels, extreme weather events, ecosystem and agricultural impacts, and public health concerns.

The dangers of global warming are evident: In 2024 alone, 27 confirmed disasters caused over $1 billion in damage and resulted in more than 550 deaths in the US. This includes Hurricane Helene, which affected North Carolina, Georgia and Florida; the wildfire that destroyed 11,000 homes in California; and the severe floods in Texas in early 2025.

Several peer-reviewed journals and national science academies raised concerns that revoking the EPA’s endangerment finding would weaken the scientific basis for US climate regulation. Scientific comments and academy statements emphasized that the endangerment finding consolidates decades of peer-reviewed evidence linking greenhouse gas emissions to widespread harms, and that removing it could hinder agencies’ ability to use that evidence in policymaking. 

A new report from the National Academies of Sciences, Engineering, and Medicine states that “the evidence for current and future harm to human health and welfare caused by human-caused greenhouse gases is beyond scientific dispute.” Across editorials and academy documents, authors pointed to converging lines of research on warming trends, studies linking emissions to extreme events and a large body of impacts research as the basis for maintaining a regulatory framework that connects scientific findings to statutory protections. 

The American Geophysical Union (AGU), a nonprofit scientific society, involved climate and health experts, submitted a signed letter and testimony at EPA public hearings, and provided comments with over 650 expert signatures supporting the endangerment finding and its scientific basis. The letter criticized the EPA’s attempts to manipulate or censor climate science with inaccurate information. This is the strategy of most anti-climate-change organizations and their supporters.

The global mean surface temperature discussion

The conservative think tank The Heartland Institute, on the other hand, praised the upcoming change. According to them, climate science spends trillions of dollars fighting climate change based on flawed assumptions, mainly because it emphasizes temperature measurements on an essentially meaningless and fabricated metric: the global mean surface temperature (GMST). 

Present anti-climate change scientists argue that GMST lacks a clear regulatory definition and is, in fact, physically meaningless under basic principles of thermodynamics. Yet, they support warming claims based on alleged temperature changes; they assert that the methodologies and assumptions used by the IPCC to identify and predict temperatures are “fundamentally fraudulent” because averaging temperatures is meaningless outside an equilibrium system, which Earth and its various climates are not. They claim that a standard measurement system should be used to obtain accurate measurements of average temperature change.

The technical analyses used to cast doubt on IPCC temperature data are part of a popular “cherry-picked” narrative, where technicalities like the GSMT are quickly discredited by physics and thermodynamics arguments. This is a common climate change denial tactic. We need to examine the IPCC’s methodology thoroughly.

The GSMT is the clearest indicator of planetary warming. It is calculated from land, ocean and satellite data that all show the same trend, and the results are reported with uncertainty ranges. Hence, policymakers understand the risks and confidence level of the numbers. Recent studies indicate that the Earth has warmed by about 1.2 °C since pre-industrial times. The agreement among different instruments, consistent methods and transparent uncertainty estimates gives this measure strong scientific credibility.

This temperature indicates the planet’s energy imbalance caused by greenhouse gases and other factors. Climate models that incorporate observed emissions successfully reproduce this trend, and research attributes most of the warming to human activities. A nearly linear relationship between cumulative carbon dioxide (CO2) emissions and temperature increase allows scientists to estimate remaining carbon budgets and timelines for reaching net zero. The temperature signal is confirmed by rising ocean heat content, shrinking glaciers and higher sea levels, providing additional supporting evidence.

For decision-makers, this metric directly links emissions to impacts, helps establish risk thresholds and guides adaptation strategies and policy choices. Its consistency, physical basis and policy relevance make it essential for monitoring global warming and focusing efforts to reduce emissions to reach net zero.

The evolution of climate science during the endangerment finding

After all, it is interesting to note the evolution of climate science from 2009 to date. Climate science has matured over the last 16 years, thus supporting all evidence for the continued “endangered finding” designation. IPCC is key to this position.

The IPCC unites 195 countries and covers three main areas: climate science, impacts and adaptation, and mitigation. It releases comprehensive assessment reports (AR) approximately every six to seven years; the current cycle is AR6. The science working group for AR6 included 234 authors from 66 countries, including coordinating and lead authors, along with hundreds of contributors; the report cites over 14,000 references and received more than 78,000 review comments. The IPCC warns that emissions must decrease by more than 40% by 2030 to prevent catastrophic outcomes. Its findings are subject to thorough expert and government review and have gained global recognition, including a share of the Nobel Peace Prize in 2007.

By the time the EPA issued the “endangerment finding”, the IPCC had already released its Fourth Assessment Report in 2007. In short, it described possible futures: the planet would warm, sea levels would rise and risks would increase if emissions continued. By 2023, the sixth assessment strengthened the science: human activity is unquestionably warming the climate; 1.5°C is likely to be reached soon under many scenarios; and many impacts and limits to adaptation are now visible. The window to prevent the worst outcomes is quickly closing. Meanwhile, anti-climate science clung to cherry-picked narratives, such as distrusting the use of GSMT, while the IPCC advanced the world’s understanding of climate change.

Over the past 16 years, IPCC assessments have strengthened the evidence and refined estimates by incorporating more observations and improved models, directly linking cumulative CO2 emissions to warming through updated carbon budgets. The scenario framework shifted to shared socioeconomic pathways with clear mitigation options, illustrating how emissions choices relate to projected temperature and sea-level changes. The report warns that risks are greater and start at lower warming levels, with damages already underway that will worsen with each additional degree, and it provides more precise short-term reduction targets and net-zero timelines to limit warming.

End-of-century temperatures now range from about 1.5°C with strong mitigation to over 4°C in high-emission scenarios, and sea levels are expected to continue rising for centuries under the worst conditions. The updated carbon budget allows only a few hundred billion tons of CO2 with a roughly 50% chance of staying near 1.5°C, highlighting the importance of reaching net-zero CO2 to prevent further long-term warming.

In the near term (up to around 2040), many pathways still allow us to limit warming to 1.5°C, but impacts will grow more severe and accumulate over time. In the long run, cumulative emissions determine the final amount of warming; delays increase the dependence on carbon removal, raise the risk of irreversible changes and lock in higher sea levels.

Net zero as a timescale: an urgent mandate

The science now reads like a timeline: deep, rapid and sustained cuts this decade, and reaching net-zero CO2, are clear paths to lower long-term risks. Delaying actions increases costs, raises risks and limits options. The choice facing governments, businesses and societies is no longer whether to decarbonize but how quickly and fairly to do it.

Separately, the EPA’s announcement is already sparking legal battles with environmental groups that have pledged to oppose proposed rollbacks. Before that fight officially begins, the agency must initiate a rulemaking process that will take months or longer to finish.

IPPC’s AR6 makes net-zero CO2 a near-term timetable, not a distant aspiration: cumulative emissions determine long-term warming, so rapid, deep cuts this decade are required to avoid locking in irreversible harms. That scientific mandate implies urgent policy actions to phase out unabated fossil infrastructure and scale clean alternatives, while pairing mitigation with adaptation and equity measures. 

Because the EPA’s “endangerment finding” is the legal foundation that allows such rules, weakening it risks immediate and significant litigation; courts will decide whether administrative rollbacks align with established science and statutory obligations, making legal challenges a key battleground for maintaining the timelines AR6 and upcoming reports require.

[Kaitlyn Diana edited this piece.]

The views expressed in this article are the author’s own and do not necessarily reflect Fair Observer’s editorial policy.