Climate change wasn’t always a partisan issue. Through the 1970s and into the late 1980s, environmental protection enjoyed broad bipartisan support in the United States. The shift toward deep political polarization happened gradually, driven by a combination of industry lobbying, strategic messaging, and international treaty battles that played out primarily between 1989 and 2002.
The Bipartisan Era of Environmentalism
In early 1970, Republican President Richard Nixon sent Congress a 37-point message on the environment that included requests for four billion dollars to improve water treatment facilities, national air quality standards, federally funded research to reduce automobile pollution, a proposed tax on lead additives in gasoline, and a plan to end waste dumping in the Great Lakes. The House and Senate approved the proposal after summer hearings, and Nixon went on to create the Environmental Protection Agency that same year. The Clean Air Act of 1970 passed the Senate 73 to 0.
For nearly two decades, protecting the environment was simply not a controversial political position. Republicans and Democrats disagreed on the details of regulation, but the basic premise that the government should act on environmental threats was shared ground.
1988: Climate Enters the National Spotlight
The moment climate change became a high-profile political issue is easy to pinpoint. On a sweltering day in June 1988, NASA scientist James Hansen testified before a U.S. Senate committee that he was “99% certain” global warming was underway. That summer happened to be one of the hottest on record, and Hansen’s testimony elevated global warming to unprecedented levels of public, media, and policy attention. Suddenly, climate wasn’t an abstract scientific concern. It was front-page news tied to hurricanes, floods, and heat waves that people could feel.
In the immediate aftermath, the response was still largely bipartisan. The U.S. government launched one of the most expensive research programs ever conducted on climate science, and both parties engaged seriously with the question of what to do about rising temperatures.
Industry Organizes Against Regulation
The political divide began taking shape just one year after Hansen’s testimony. In 1989, a coalition of fossil fuel companies, utilities, and manufacturers formed the Global Climate Coalition (GCC), housed within the National Association of Manufacturers. Its founding members read like a roster of American industrial power: the American Petroleum Institute, the National Coal Association, Shell Oil Company, Texaco, Amoco, Peabody coal, American Electric Power, and Pacific Gas and Electric, among others.
The GCC’s goal was straightforward: oppose greenhouse gas regulations. It operated from 1989 to 2002, directly engaging lawmakers and collaborating with affiliated voices who cast doubt on climate science. This was the beginning of a well-funded, organized effort to reframe climate action as an economic threat rather than an environmental necessity.
The spending grew dramatically over the following decade. A Drexel University study tracked 140 foundations that made over 5,299 grants totaling $558 million to 91 organizations between 2003 and 2010 alone. Koch-affiliated foundations and the ExxonMobil Foundation were heavily involved in funding these efforts from 2003 to 2007. This money flowed to think tanks, advocacy groups, and media operations that worked to keep climate science contested in the public mind, even as the scientific consensus solidified.
The Kyoto Protocol Crystalizes the Split
If industry lobbying laid the groundwork for polarization, international climate negotiations made it visible. In 1992, President George H.W. Bush traveled to the Rio Earth Summit and signed the United Nations Framework Convention on Climate Change. The convention called on countries to reduce greenhouse gas emissions, though it set no mandatory targets, largely at the insistence of U.S. negotiators. At that point, a Republican president could still sign an international climate agreement without significant backlash from his own party.
Five years later, the politics had shifted dramatically. In 1997, the Senate voted 95 to 0 on the Byrd-Hagel Resolution, which declared the U.S. should not sign any climate treaty that exempted developing nations or could seriously harm the American economy. Not a single senator from either party voted against it. The resolution didn’t mention the Kyoto Protocol by name, but it was a direct response to the treaty then being negotiated in Japan. Opponents argued that Kyoto would cost the economy billions of dollars and put as many as two million Americans out of work. Some framed it as a sovereignty issue, claiming the executive branch was trying to implement treaty obligations through regulation without proper Senate approval.
The Kyoto Protocol was never submitted to the Senate for ratification. By the time George W. Bush formally withdrew the U.S. from the agreement in 2001, climate policy had become firmly associated with partisan identity. Supporting emissions cuts increasingly marked you as a Democrat; opposing them marked you as a Republican.
How Language Became a Weapon
The politicization of climate change wasn’t only about policy positions. It was also deliberately engineered through language. In 2002, Republican strategist Frank Luntz wrote an influential memo advising the party on how to talk about environmental issues. His recommendations were specific and calculated.
Luntz urged Republicans to call themselves “conservationists” rather than “environmentalists” or “preservationists,” because the word carried more positive associations. More consequentially, he recommended using the phrase “climate change” instead of “global warming.” His reasoning: “global warming” sounded more catastrophic, less controllable, and more emotionally challenging. “Climate change” felt less alarming. These weren’t idle suggestions. The memo was widely adopted, and the terminology shift became visible in Republican talking points almost immediately. The fact that even the words used to describe the problem became a matter of political strategy shows how deeply the issue had been absorbed into partisan identity.
Why the Split Stuck
Several forces converged to make climate change one of the most polarized issues in American politics. The fossil fuel industry had enormous economic incentives to delay regulation and spent hundreds of millions of dollars doing so. International treaties like Kyoto tied climate action to questions about American sovereignty and economic competitiveness, issues that split neatly along existing partisan lines. Conservative think tanks, funded by industry donors, provided a steady stream of arguments that kept the “debate” alive in political circles long after it had been settled in scientific ones.
The timeline matters because it reveals that the polarization was not inevitable. For roughly two decades after the modern environmental movement began, climate and environmental protection commanded broad support from both parties. The shift happened in a specific window, roughly 1989 to 2002, driven by identifiable actors making strategic decisions about money, messaging, and political advantage. What started as a scientific question became an economic argument, then a sovereignty dispute, then a cultural identity marker. Each layer made the divide harder to bridge.