In a move that has reverberated across the globe, President Donald Trump’s administration announced in early 2025 that the United States would withdraw from the Paris climate agreement for the second time, reigniting fears that America’s retreat could undermine worldwide efforts to fight climate change. The announcement, coupled with a series of aggressive deregulatory actions targeting federal climate policy, has left many wondering: who will now lead the charge against global warming?
According to The Conversation, the U.S. originally joined the Paris Agreement in 2015 under President Barack Obama, pledging to reduce its greenhouse gas emissions by 26% to 28% below 2005 levels by 2025. Yet by this year, the U.S. had only managed a 17.2% reduction—falling short of its commitment, hampered by political and legislative obstacles.
This latest withdrawal echoes Trump’s first exit from the Paris accord in 2017, when he cited concerns over job losses, economic burdens, and what he deemed an unfair playing field with China, the world’s largest emitter. At the time, many scientists, politicians, and business leaders lambasted the decision as “shortsighted” and “reckless,” fearing the agreement—signed by nearly every country—might collapse. But the global response defied those fears.
Major American corporations like Apple, Google, Microsoft, and Tesla publicly vowed to continue pursuing the Paris Agreement’s goals, regardless of federal policy. Hawaii became the first state to legislate alignment with the agreement, and a coalition of states and cities formed the United States Climate Alliance to keep the country moving toward emissions reductions. Internationally, leaders from Italy, Germany, and France dismissed Trump’s suggestion that the Paris deal could be renegotiated, while Japan, Canada, Australia, and New Zealand doubled down on their own climate commitments.
President Joe Biden’s return to the White House in 2020 saw the U.S. rejoin the agreement, but Trump’s 2025 re-election has once again reversed course. This time, the administration is not only withdrawing from the Paris accord but also dismantling key domestic climate policies and boosting fossil fuel development, while slowing the growth of clean energy at home.
The most consequential of these moves came on September 20, 2025, when the Trump administration proposed overturning the Environmental Protection Agency’s (EPA) 2009 “endangerment finding”—the scientific determination that greenhouse gases are a hazard under the Clean Air Act. As reported by NPR, this finding has been the legal bedrock for federal action on climate change for over a decade, underpinning regulations on power plants, vehicle emissions, and methane from oil and gas operations.
EPA Administrator Lee Zeldin, announcing the proposal at a car dealership in Indiana, argued that “with this proposal, the Trump EPA is proposing to end sixteen years of uncertainty for automakers and American consumers.” The administration contends the EPA lacks legal authority to regulate greenhouse gases, calling the 2009 finding “flawed and unorthodox.” Zeldin further asserted, “We are driving a dagger straight into the heart of the climate change religion to drive down cost of living for American families, unleash American energy, bring auto jobs back to the U.S. and more.”
The proposal also seeks to eliminate rules that limit climate pollution from cars and trucks—currently the largest source of direct greenhouse gas emissions in the United States. Environmental advocates, however, have vowed fierce resistance. Christy Goldfuss of the Natural Resources Defense Council warned, “As Americans reel from deadly floods and heat waves, the Trump administration is trying to argue that the emissions turbocharging these disasters are not a threat. It boggles the mind and endangers the nation's safety and welfare.”
This deregulatory blitz comes in the wake of the hottest year ever recorded on Earth, with the U.S. experiencing devastating floods, wildfires, and hurricane-fueled destruction. Critics argue that rolling back these protections ignores urgent scientific warnings and the mounting human and economic costs of climate-fueled disasters. Dan Becker of the Center for Biological Diversity wrote to NPR, “By revoking this key scientific finding Trump is putting fealty to Big Oil over sound science and people's health.”
Legally, the Trump administration’s path is fraught with obstacles. The 2007 Supreme Court decision in Massachusetts v. EPA required the agency to regulate carbon dioxide and other greenhouse gases. The 2009 endangerment finding, established under Obama, has been reaffirmed multiple times and was further bolstered by the 2022 Inflation Reduction Act, which explicitly labeled greenhouse gases as pollutants under the Clean Air Act. Overturning this foundation would not only face public comment and legal challenges but would also make it harder for future administrations to limit emissions.
While Washington’s climate leadership recedes, other nations are stepping in. On July 24, 2025, China and the European Union issued a joint statement vowing to strengthen their climate targets, pointedly referencing “the fluid and turbulent international situation today” and calling on “the major economies… must step up efforts to address climate change.” China, in particular, appears poised to fill the leadership vacuum. As The Conversation notes, China has pledged $3.1 billion in climate finance to developing countries—outstripping the U.S. commitment—and has set ambitious goals to peak emissions before 2030 and achieve net-zero by 2060. In 2024 alone, China accounted for about half of all new renewable energy capacity built worldwide.
China’s investments extend beyond its borders, with the Belt and Road Initiative channeling funds into solar projects in Egypt and wind developments in Ethiopia. Domestically, China continues to expand its renewable energy sector and recently broadened its carbon market to cover the cement, steel, and aluminum industries. Meanwhile, the British government has also increased its climate ambitions, pledging in 2025 to cut emissions by 77% by 2035 compared to 1990 levels, and providing more transparent sector-by-sector plans and increased funding for sustainable growth in developing countries.
Back in the U.S., many corporations are quietly continuing their own climate efforts, even as federal support wanes. According to USA Today and Statista, the “America’s Climate Leader List” now includes about 500 large companies that have reduced their carbon intensity by at least 3% year-over-year, up from roughly 400 in 2023.
The next major test for global climate leadership will come at the United Nations climate conference in Brazil, COP30, later this year. There, the world will see not only how countries intend to move forward but also who will take the lead in balancing economic growth with ecological sustainability in the face of America’s retreat.
As the U.S. steps back, the resilience of the Paris Agreement and the emergence of new climate champions suggest that the global fight against climate change will continue—though the path ahead is sure to be more contested and uncertain than ever before.