President-elect Donald Trump's nomination of Exxon Mobil CEO Rex Tillerson for secretary of state comes as the oil giant is locked in a battle with environmental groups, more than a dozen state attorneys general and the Rockefeller Family Fund.

David Kaiser, the great-great-grandson of John D. Rockefeller, offered evidence in a series of articles in the New York Review of Books that Exxon Mobil’s scientists decided in the late-1980s to deny climate change to protect its interests. Exxon denies these charges, and says Rockefeller is funding a conspiracy.

Here & Now's Robin Young talks with Kaiser about the allegations.