Smoke & Fumes: the Deep History of Oil and Climate Change

This is the story of how major oil and gas companies and their associations — the world’s most powerful industry — used science, communications, and consumer psychology to shape the public debate over climate change is becoming increasingly well documented. And it begins earlier—decades earlier—than anyone suspected.  Check out the timeline below and links to documents to discover what they knew, when they knew it, and how they collaborated to confuse the public, promote scientific theories that contradicted their own best information, and block action on the most important issue facing the world today.


Growing public evidence demonstrates that Exxon and other oil companies understood climate risks by the 1980s, yet spent millions to sow uncertainty and misinformation about climate science.

The documents that follow—industry histories, scientific articles, oral testimonies, patents—span more than half a century of industry research and industry action. They offer compelling evidence that oil executives were actively debating climate science in the 1950s, and were explicitly warned about climate risks a decade later. Just as importantly, they offer glimpses into why the industry undertook this research, and how it used the results to sow scientific uncertainty and public skepticism.



They also acknowledged that fossil fuel burning provided the best explanation for rising CO2. They further recognized that existing science was “detailed” and seemed “to adequately explain the present state of CO2 in the atmosphere.” And they concluded that the most important research need was technologies and “systems in which CO2 emissions would be brought under control.”



In late 1946, as public concern and media scrutiny mounted, executives from the Western Oil and Gas Association met in Los Angeles to consider a response. They emerged with a plan—and a Committee. Comprised of executives from leading oil companies (including Union Oil, Standard Oil of California (both now part of Chevron), Esso (now ExxonMobil), and Shell), the newly-created Smoke and Fumes Committee would fund scientific research into smog and other air pollution issues and, significantly, use that research to inform and shape public opinion about environmental issues. The express goal of their collaboration was to use science and public skepticism to prevent environmental regulations they deemed hasty, costly, and unnecessary.

Recognizing that the air pollution issues in Los Angeles could foreshadow the emergence of similar risks across the country, the Smoke and Fumes Committee was reorganized with a national mandate in 1952 within the American Petroleum Institute. It continued to operate, under a succession of names—but many of the same people—for the ensuing two decades. The Jones report documents that by 1958 at the latest, the Committee was funding research into the role of fossil fuels in rising levels of atmospheric carbon dioxide.



Much of the Smoke and Fumes Committee’s air pollution research was carried out at SRI. As experience with smog would demonstrate, the resulting scientific reports became an important and recurring tool in the oil industry’s campaign to cast doubt on both the science and the scientists that disagreed with them. And, as recounted by researcher Harold Johnston, hires and fires at SRI could be dictated by the Smoke and Fumes Committee and influenced by researchers’ opinions of the science in question.


The concept of climate change gained new relevance in the late 1930s, when Guy Callendar documented a decades-long increase in global temperatures and correlated that increase with rising fossil fuel use. Over the ensuing decade, scientific interest in the climate question continued to grow. During much of this period, however, it was widely assumed that the oceans covering 70% of the planet’s surface would absorb the excess CO2 released by human activity, and mute any impact on the atmosphere.

In 1955, Scripps Institute scientist Hans Suess demonstrated that naturally occurring carbon-14 in the atmosphere was being “diluted” by depleted carbon-12 derived from fossil fuels. Suess’s 1955 paper provided the first clear proof that, as hypothesized by Arrhenius and theorized by Callendar, carbon dioxide from the combustion of fossil fuels was accumulating in the atmosphere. With this work, the era of intensive of climate science began. During the same period, oil industry scientists—led by Humble Oil’s (now ExxonMobil) H.R. Brannon—were actively engaged in carbon-14 research, and uniquely equipped to understand and shape the climate science revolution that evolved rapidly over the next few years.



Two months after the Revelle and Suess paper was published, Humble Oil (now ExxonMobil) scientists led by H.R. Brannon submitted their own study for publication on the same question. Building on the team’s earlier work on radiocarbon dating, and submitting under the company’s name, the Brannon paper provides the earliest indisputable evidence we have yet found of oil company knowledge of climate science and climate risk. Significantly, the Brannon report acknowledges not only rising levels of atmospheric CO2, but also the evident contribution of fossil fuels to that increase. In acknowledged disagreement with Revelle, however, the Brannon paper suggests that CO2 would be retained in the oceans much longer before returning to the atmosphere, which would delay by decades or centuries the impact of fossil fuel emissions.




Not only does the report acknowledge the link between rising atmospheric CO2, the risk of climate change, and that fossil fuels are the most likely culprit, it affirms that the underlying science is sound, and that the most important research needs were in technologies to reduce CO2 emissions. We know the Robinson report was seen by industry leaders. In 1971, Robinson delivered the major findings of the study to industry experts gathered at the World Petroleum Congress. A 1972 industry report authored by a steering committee of high-level executives was submitted to the Department of Interior on air pollution issues. It relied on Robinson’s report and publicly referred to “their careful study” by “eminent scientists” as an authoritative source on atmospheric pollution. Significantly, both the 1971 speech and the 1972 report placed a far greater emphasis on scientific uncertainties than Robinson himself did, and relied on those uncertainties to support a “wait and see” approach to climate action.

How could the industry explain ignoring the climate findings of its own scientific report even as it embraced that report on other pollution issues? In 1969, API hastily commissioned a “Supplemental” report from Robinson that took a more skeptical, more equivocal approach to climate science. API relied on that Supplemental report in its subsequent questioning of climate science, and industry and climate skeptics continued to cite it for years afterward.  That latter report will be available soon.


By the 1960s, oil companies were sponsoring research at the forefront of atmospheric science and using high-powered electric computers to develop complex climate models for use in storm forecasting.  Because an increase in storm frequency and severity is one of the predicted consequences of climate change, understanding how storms form, and being able to predict them, is fundamental to climate science and understanding climate change.

1949, A.H. GLENN…


Among the results of these studies was the explicit mapping of periods of rising sea level onto periods of warming. This gave the industry unique insight into one of the most significant consequences of climate change—sea level rise driven by rising global temperatures.


In the United States alone, four state Attorneys General have already launched investigations, with more expected to follow.  At the federal level, requests for investigation into Exxon’s activities have been referred to the Securities and Exchange Commission and the Federal Bureau of Investigation.  In the Philippines, the National Commission on Human Rights has taken up a petition by organizations and Typhoon Haiyan survivors demanding accountability from the oil companies that violated their human rights.

If oil companies misrepresented or concealed material facts about their products from the consumers, investors, and the public in the name of profit, they committed fraud. If the oil industry had notice of the risks of its products to the global environment and to this and future generations around the world, they had a duty to warn consumers—and the public—of those risks. If the oil industry not only failed to do so, but also actively worked to conceal the risks for decades, they must be held accountable.