Oil giant Exxon conducted cutting-edge climate research in the 1970s, and then, without disclosing the findings of its scientists, worked to manufacture doubt about the scientific consensus of its own research.

A groundbreaking investigation shows how the company’s top executives were warned of possible catastrophe from global warming, then led efforts to block solutions.

InsideClimate News explains:

At a meeting in Exxon Corporation’s headquarters, a senior company scientist named James F. Black addressed an audience of powerful oilmen. Speaking without a text as he flipped through detailed slides, Black delivered a sobering message: carbon dioxide from the world’s use of fossil fuels would warm the planet and could eventually endanger humanity.

“In the first place, there is general scientific agreement that the most likely manner in which mankind is influencing the global climate is through carbon dioxide release from the burning of fossil fuels,” Black told Exxon’s Management Committee, according to a written version he recorded later.

It was July 1977 when Exxon’s leaders received this blunt assessment, well before most of the world had heard of the looming climate crisis.

A year later, Black, a top technical expert in Exxon’s Research & Engineering division, took an updated version of his presentation to a broader audience. He warned Exxon scientists and managers that independent researchers estimated a doubling of the carbon dioxide (CO2) concentration in the atmosphere would increase average global temperatures by 2 to 3 degrees Celsius (4 to 5 degrees Fahrenheit), and as much as 10 degrees Celsius (18 degrees Fahrenheit) at the poles. Rainfall might get heavier in some regions, and other places might turn to desert.

“Some countries would benefit but others would have their agricultural output reduced or destroyed,” Black said, in the written summary of his 1978 talk.

His presentations reflected uncertainty running through scientific circles about the details of climate change, such as the role the oceans played in absorbing emissions. Still, Black estimated quick action was needed. “Present thinking,” he wrote in the 1978 summary, “holds that man has a time window of five to ten years before the need for hard decisions regarding changes in energy strategies might become critical.”

Exxon responded swiftly. Within months the company launched its own extraordinary research into carbon dioxide from fossil fuels and its impact on the earth. Exxon’s ambitious program included both empirical CO2 sampling and rigorous climate modeling. It assembled a brain trust that would spend more than a decade deepening the company’s understanding of an environmental problem that posed an existential threat to the oil business.

Then, toward the end of the 1980s, Exxon curtailed its carbon dioxide research. In the decades that followed, Exxon worked instead at the forefront of climate denial. It put its muscle behind efforts to manufacture doubt about the reality of global warming its own scientists had once confirmed. It lobbied to block federal and international action to control greenhouse gas emissions. It helped to erect a vast edifice of misinformation that stands to this day.

This untold chapter in Exxon’s history, when one of the world’s largest energy companies worked to understand the damage caused by fossil fuels, stems from an eight-month investigation by InsideClimate News. ICN’s reporters interviewed former Exxon employees, scientists, and federal officials, and consulted hundreds of pages of internal Exxon documents, many of them written between 1977 and 1986, during the heyday of Exxon’s innovative climate research program. ICN combed through thousands of documents from archives including those held at the University of Texas-Austin, the Massachusetts Institute of Technology and the American Association for the Advancement of Science.

The documents record budget requests, research priorities, and debates over findings, and reveal the arc of Exxon’s internal attitudes and work on climate and how much attention the results received.