The Guardian reports that Exxon learned a useful trick from the tobacco business:

Read all of these documents and make up your own mind.

That was the challenge ExxonMobil issued when investigative journalism by Inside Climate News revealed that while it was at the forefront of climate science research in the 1970s and 1980s, Exxon engaged in a campaign to misinform the public.

Harvard scientists Geoffrey Supran and Naomi Oreskes decided to take up Exxon’s challenge, and have just published their results in the journal Environmental Research Letters. They used a method known as content analysis to analyze 187 public and internal Exxon documents. The results are striking:

• In Exxon’s peer-reviewed papers and internal communications, about 80% of the