Oil company executives testified about drilling safety in front of Congress in 2010Oil company executives, testifying to Congress in 2010 about drilling safety, may face new inquiries about how their companies have dealt with climate change. Photo credit: Mark Wilson/Getty Images

By Ucilia Wang

Oil companies are facing an increasing number of lawsuits that aim to hold them responsible for the impacts of climate change. What the companies knew about their contributions to global warming will answer some key legal questions, including whether they have sold products while knowing they would cause public harm.

A new group of documents was revealed on Thursday, detailing Shell’s history of studying climate change and its impacts. The documents show that not only did the company understand its role in climate change for the past several decades, but also predicted that legal liability awaited. The documents were found by Jelmer Mommers, a journalist for De Correspondent, and are available at the Climate Files website.

They are similar to the documents that the nonprofit news organization InsideClimate News unearthed in 2015 about Exxon’s decades of climate science knowledge.

Here is a timeline that shows internal research and discussions by some of the biggest oil companies over the past 40 years and how their public statements and campaigns often included very different messages. It begins to draw the picture of what the fossil fuel industry knew about climate change and when and how it contrasted with their public stance:

July 1977: James Black, a scientist at Exxon, told the company’s top management that scientific evidence showed burning fossil fuels was causing climate change.

May 1981: In a paper written for Exxon’s head of research, the company scientist Henry Shaw estimated that global temperatures will increase by 3 degrees Celsius with the doubling of the carbon dioxide emissions in the atmosphere, which could cause catastrophic impacts as early as the first half of the 21st century.

November 1982: Exxon distributed a paper internally on climate change that advised “major reductions in fossil fuel combustion” for limiting global warming.

June 1988: James Hansen, a NASA scientist, testified during a congressional hearing that human activities were causing global warming. It was the first major public warning of a looming climate crisis.

1988: Shell prepared an internal report called “The Greenhouse Effect” that analyzed the impacts of climate change. It noted that fossil fuel burning was driving climate change and quantified the carbon emissions from its products (oil, gas, coal) made up 4 percent of global emissions in 1984.

1989: In a move to coordinate a public response to the growing attention on climate change, a group of big businesses, including Exxon, BP and Shell, formed the Global Climate Coalition. It set out to cast doubt on climate science and lobby against efforts to reduce greenhouse gas emissions.

February 1995: An internal report by Shell warned that fossil fuel burning was the main source of manmade emissions that was driving global warming, and this fact “could have major business implications for the fossil fuel industry.”

1991: A 30-minute video produced by Shell included dire predictions and images of fires, floods and food shortages. A narrator included this ominous warning: “Global warming is not yet certain, but many think that to wait for final proof would be irresponsible. Action now is seen as the only safe insurance.”

1996: Exxon solidified its public stance on dealing with climate change when chief executive Lee Raymond wrote an article for a company publication saying that scientific evidence was “inconclusive” on whether humans were contributing to climate change.

1997: Exxon took out an ad in the New York Times that was titled, “Reset the Alarm,” which said: “Let’s face it: The science of climate change is too uncertain to mandate a plan of action that could plunge economies into turmoil.”  It also read, “We still don’t know what role man-made greenhouse gases might play in warming the planet.”

1998: In a speech to employees, Lucio Noto, chief executive of Mobil Oil (before its merger with Exxon) told employees who were apparently  were upset about “what they think is Mobil’s negative attitude on the Kyoto so-called climate agreement.” His speech was captured on video. He said while there’s a connection between greenhouse gases and climate change, “we are also not prepared to admit that the science is a closed fact, and that we should take draconian steps tomorrow to reduce CO2 gases.” He also said the company should try to reduce its operational emissions as well as those produced by customers.

1998:  Shell produced a document called the Shell Internal TINA Group Scenarios 1998-2020 Report, which included modeling a future that included oil companies and governments being held liable for climate impacts. Its scenario eerily described the U.S. being hit with fierce storms in 2010, followed by activist groups initiating legal liability cases. (In reality, the biggest storm him the East Coast in 2012—Superstorm Sandy—and liability cases began to stir after that.)

2009: In a filing with the U.S. Securities and Exchange Commission, Exxon acknowledged  that humans were causing climate change.

2013: A study by Richard Heede published in the journal Climatic Change showed that 90 companies are responsible for two-thirds of the carbon emissions since the start of the industrial age in the mid-18th century.

August 2017: A Harvard study that analyzed Exxon’s internal papers and public statements and campaigns showed the company misled the public about what it knew about the risk of climate change. The peer-reviewed study concluded that Exxon emphasized doubts about the scientific evidence that blamed fossil fuel burning for global warming when communicating with the public while acknowledging the issue more forthrightly in internal communications.