The world’s largest oil company has been under some scrutiny lately. Back in 2015, Inside Climate News and the Los Angeles Times published a pair of matching exposes on Exxon, using internal documents to show that the company was well aware of the threat of climate change as far back as the 1970s, but consistently misled the public and investors about it.

Now ExxonMobil is under siege from even more directions. Seventeen state attorneys general have said they will begin cooperating on investigations into whether Exxon broke racketeering, consumer protection, or investor protection laws in its climate communications. New York AG Eric Schneiderman, Massachusetts AG Maura Healey, and US Virgin Islands AG Claude Walker are all leading separate investigations. And in 2016, the US Securities and Exchange Commission launched its own federal investigation. All these investigations have inspired class-action lawsuits.

Exxon, not surprisingly, has denied all charges. It claims that it has been open and honest about climate change and that journalists are using “deliberately cherry-picked statements” to build their case.

In response to the 2015 articles, the company issued a challenge: “Read all of these documents and make up your own mind.”

Here’s a good lesson for #brands everywhere: Don’t issue reading-based challenges to a community full of nerds.

A couple of researchers at Harvard decided to take them up on it. They gathered every document, read them, did a thorough content analysis, and have just published the results in a peer-reviewed academic journal, Environmental Research Letters.

Spoiler: Yes, Exxon misled the public.

Exxon’s climate communications show internal honesty, outward-facing doubt

Geoffrey Supran, a post-doctoral fellow in Harvard’s History of Science program, and Naomi Oreskes, his post-doc adviser (and of course a noted science historian and author, most famously of Merchants of Doubt), did the yeoman’s work of wading through all the Exxon documents.

They found 187 overall, a mix of “peer-reviewed and non-peer-reviewed publications, internal company documents, and paid, editorial-style advertisements (‘advertorials’) in The New York Times.” (Exxon bought an advertorial in the Times every Thursday between 1972 and 2001 — one quarter of all the advertorials on the op-ed page.)

They did content analysis (a common social science method) of the documents, scoring various attributes, such as whether the document treated climate change as a) real and human caused, b) serious, and c) solvable.

The primary takeaway is this: In its public-facing advertorials, Exxon stressed doubt; in its internal documents and peer-reviewed research, it did not.

Specifically, 83 percent of its peer-reviewed papers and 80 percent of its internal documents acknowledge that climate change is real and human-caused, while only 12 percent of advertorials do. Some 81 percent of the relevant advertorials express doubt.

“We conclude that ExxonMobil contributed to advancing climate science—by way of its scientists’ academic publications—but promoted doubt about it in advertorials,” Supran and Oreskes write. “Given this discrepancy, we conclude that ExxonMobil misled the public.”

Exxon’s history with gaming the public

The internal documents uncovered by journalists show that “by the early 1980s, ExxonMobil scientists and managers were sufficiently informed about climate science and its prevailing uncertainties to identify [anthropogenic global warming] as a potential threat to its business interests.” In response, the company set up two initiatives, one focused on science, the other on public relations.

The scientific program was run under Exxon Research and Engineering (ER&E), which in 1984 described its approach thusly: “Establish a scientific presence through research program in climate modeling; selective support of outside activities; maintain awareness of new scientific developments.”

One scientist — Dr. Haroon S. Kheshgi, hired by Exxon in 1986 — produced the bulk (52 out of 72) of Exxon’s peer-reviewed publications on climate change. He’s an IPCC contributing author with a storied CV. (Indeed, the authors write, “the metadata title of the ‘Exxon Mobil Contributed Publications’ file is ‘Haroon’s CV’.”) He seems to have held down the “establish a scientific presence” front.

Part of establishing a research presence was to use it as a credibility-booster in talks with governments (“great public relations value,” said a 1978 memo). It has been used that way since and is being used by Exxon even today.

And then there was the public communications plan, which by the late-1980s “explicitly aimed to ‘extend the science’ and ‘emphasize the uncertainty in scientific conclusions regarding the potential enhanced Greenhouse effect’.” The advertorials “overwhelmingly emphasized only the uncertainties, promoting a narrative inconsistent with the views of most climate scientists, including ExxonMobil’s own.”

For instance, look at this doozy from 1997:

Vintage. Another 1997 advertorial says:

Committing to binding targets and timetables now will alter today’s lifestyles and tomorrow’s living standards. Flexibility will be constrained. Carpooling in; sport utility vehicles out. High fuel and electric bills. Factory closures. Job displacement. And could businesses and consumers cut their energy consumption by 30 percent without some form of tax or carbon rationing? Probably not.

Somehow, in the end, SUVs survived Kyoto.

This advertorial from 2000 is called “Unsettled Science.” It’s a classic of the climate-skeptic genre, with all the greatest hits: natural variability, medieval ice age, models don’t work, CO2 is good for crops. It shows a graph of sea-surface temperatures, misleadingly implying that it’s a graph of global temperatures (a move the scientist who produced the original graph called “very misleading”).

And it contains this immortal sentence: “Natural variability and human activity may lead to climate change that could be significant and perhaps both positive and negative.” That’s just 20 words and they got a “may,” a “could,” and a “perhaps” in there!

Anyway, the point is, Exxon’s decision to tell the public one thing even as it acknowledged another internally goes way back, back to when it first began to understand what climate change represented.

Whether any of this constitutes legal liability is a question neither the researchers nor I are equipped to adjudicate. But as to the basic question of whether Exxon has been trying to pull one over on the public, a full and fair assessment of its record suggests: Yes, it has.