NULL — The Center for International Environmental Law released a report titled “What Countries Knew” on a Wednesday, detailing how major fossil fuel–emitting nations were informed decades ago about the climate risks of burning coal, oil, and gas. The report identifies eight countries— the United States, Australia, Canada, Germany, Italy, Norway, the United Kingdom, and the combined Soviet Union and Russia—as collectively responsible for about 40 percent of global emissions since the fossil fuel era began in the late 1800s.

According to the report, climate scientists presented these governments with research on the dangers of greenhouse gas emissions far earlier than commonly acknowledged. Summaries and transcripts from international scientific conferences show that officials discussed the risks of rising global temperatures, melting polar ice caps, and sea-level rise as early as 1957 during the International Geophysical Year, a period when about 70 countries collaborated to study Earth as an interconnected system and measure the growing effects of human activities on the planet.

In that same year, American scientists Roger Revelle and Hans Suess published a study describing the accumulation of carbon dioxide in the atmosphere as an unprecedented and irreversible “large-scale geophysical experiment” unlike anything in human history. By 1965, U.S. scientists had directly warned President Lyndon Johnson that rising carbon dioxide levels could cause “marked changes” in climate. Around the same time, researchers at state-owned oil companies in Norway and Italy also warned of potential climate impacts, even as their governments encouraged continued expansion of fossil fuel production.

The report further documents that discussions about climate change and alternatives to fossil fuels persisted through the following decades. A 1968 government-and-industry symposium in France included detailed talks on non-fossil energy sources. In 1973, the International Institute for Applied Systems Analysis in Austria hosted discussions focused on potential government responses to climate change. Throughout the 1970s, Canadian federal agencies circulated newsletters in which scientists openly discussed climate change.

Nikki Reisch, climate and energy program director at the Center for International Environmental Law, emphasized that scientific findings were widely shared. “It was being published, disseminated. Their information was communicated directly to government officials, sometimes at the highest levels and to the broader public.

All this information was in the hands of those who could have acted,” Reisch said. Lindsay Fenlock, a senior researcher at the organization and lead author of the report, added, “I think that just how much was known, and how soon, was pretty shocking. But people don’t talk about it now.”

The report’s release comes in the wake of a legal development: last year, the International Court of Justice issued an advisory opinion stating that nations have longstanding legal obligations to prevent climate harm and may be required to pay reparations when their failure to act causes damage. Michael Burger, executive director of the Sabin Center for Climate Change Law at Columbia University, described the new report as “a warning shot, for those on the lookout for cases that may follow in the wake of the ICJ’s opinion.”

The “What Countries Knew” report provides documentary evidence that major emitting nations had access to scientific warnings about climate change beginning in the 1950s and 1960s, long before climate policy became a global priority. This historical record may inform legal and diplomatic efforts to hold states accountable for past inaction, particularly in light of the International Court of Justice’s recent advisory opinion on state obligations and potential liability for climate damages.

By documenting early awareness among governments that together account for 40 percent of historic emissions, the report challenges narratives that climate change was unforeseen or scientifically uncertain until recent decades. The findings could influence ongoing debates over climate justice, reparations, and the allocation of responsibility for mitigation and adaptation costs in international forums.