Since taking over as Exxon's chairman three months ago from Lee R. Raymond, his abrasive predecessor who dismissed fears of global warming and branded environmental activists "extremists," Mr. Tillerson has gone out of his way to soften Exxon's public stance on climate change.


"We recognize that climate change is a serious issue," Mr. Tillerson said during a 50-minute interview last week, pointing to a recent company report that acknowledged the link between the consumption of fossil fuels and rising global temperatures. "We recognize that greenhouse gas emissions are one of the factors affecting climate change."

But despite the shift in style to a less adversarial tone, the substance of Exxon's position has not changed with the new chairman. The company said the recent report only clarified its long-held position on global warming. Indeed, Mr. Tillerson noted that he, like Mr. Raymond before him, remained convinced that there was "still significant uncertainty around all of the factors that affect climate change."