Exxon is currently under investigation by the attorneys general of Massachusetts, New York and the U.S. Virgin Islands for researching climate change in the 1970s and then deliberately misleading investors and the public... However, simply because of the extreme views at the top of other agencies, it's possible that Tillerson would be a moderating voice within the Trump cabinet on climate change, assuming he's confirmed... Tillerson moved to have the company acknowledge the central role that human-caused greenhouse gas emissions play in global warming, and advocated for a revenue neutral carbon tax as the most economically elegant solution to putting a price on carbon emissions... Exxon has also, at least publicly, been supportive of the Paris Climate Agreement... 

Still, there are many reasons to question Tillerson’s climate change bona fides... First, some of the climate deniers that his company funded are now involved in the Trump administration’s transition at the EPA, Energy Department and other parts of the bureaucracy... Friends of the Earth U.S. president Erich Pica...[said] "For decades ExxonMobil covered up its knowledge of the link between fossil fuels and climate change, while funding climate denial groups"... [The] company has poured millions into tar sands oil fields in Alberta, which contain some of the dirtiest, most greenhouse gas intensive oil on the planet.