4 A5: ExxonMobil is under scrutiny on several legal fronts. From investigations by the Attorneys General of New York and Massachusetts and by the Securities and Exchange Commission, to lawsuits by cities including New York City and San Francisco and some of ExxonMobil’s own employees and shareholders, to this enquiry by the Philippines Commission on Human Rights, a common question has emerged: have ExxonMobil’s communications about climate change misled its customers, shareholders, or the general public, including in ways that may have broken the law? (Unless specified otherwise, I refer to ExxonMobil Corporation, Exxon Corporation, and Mobil Oil Corporation as “ExxonMobil”.) ExxonMobil says the allegations are false and “deliberately cherry-picked” and that anyone who looks at the evidence will see that. They challenged the public to “Read all of these documents and make up your own mind.” At Harvard University, Professor Naomi Oreskes and I took up this challenge. Over the course of a year, we read all of the documents made available by ExxonMobil, as well as some additional relevant ones, and analyzed them according to established social science methods. The result of our study was, to our knowledge, the first peer-reviewed, academic analysis of ExxonMobil’s 40-year history of climate change communications, published in the journal Environmental Research Letters [2]. Our findings are clear: ExxonMobil misled the public about the state of climate science and its implications. Available documents show systematic, quantifiable discrepancies between what ExxonMobil’s scientists and executives discussed about climate change in private and in academic circles, and what it presented to the general public. Our research was supported by Harvard University Faculty Development Funds and by the Rockefeller Family Fund. Neither Naomi Oreskes nor I have any other relevant financial ties, and we declare no conflicts of interest. Q6: How is your article or study unique? A6: To our knowledge, our study is the first peer-reviewed, academic analysis of ExxonMobil’s 40-year history of climate change communications. Part of the impetus for suspicions about ExxonMobil’s knowledge and communications on climate change was reporting by the news organizations Inside Climate News and Los Angeles Times in 2015, which concluded ExxonMobil had long known about the risks of climate change but denied them in public [3,4]. Our research extends the journalists’ work by providing an independent, empirical, and expansive corroboration of their finding that ExxonMobil has known for decades about the basics of climate science and its implications. We further show that, both simultaneously and in subsequent years, the company communicated positions to the general public that were at odds with this knowledge. We identify systematic discrepancies between what