JUDY WOODRUFF:

And joining me now is Kenneth Cohen. He is vice president for public and government affairs with ExxonMobil Corporation.

Kenneth Cohen, welcome.

Let me just begin by asking flat out, has Exxon in any way misled or been dishonest with the public about what it knows about climate change?

KENNETH COHEN, Vice President of Public & Government Affairs, Exxon Mobil Corporation: Well, Judy, first, thank you for the invitation to come on tonight's program.

And I also appreciate opening with that question, because the answer is a simple no. And what the facts will show is that the company has been engaged for many decades in a two-pronged activity here.

First, we take the risks of climate change seriously. And we also have been working to understand the science of climate change. And that activity started in the late '70s and has continued up to the present time. Our scientists have produced over 150 papers, 50 of which have been part of peer-reviewed publications.

Our scientists participate in the U.N.'s climate body. We have been participating in the U.N. activities beginning in 1988, running through the present time. At the same time, we have also been engaged in discussions on policy.

And in the discussions on policy, for example, in the late '90s, we were part of a large business coalition that opposed adoption in the U.S. of the Kyoto protocol. Now, why did we do that? We opposed the Kyoto protocol because it would have exempted from its application over two-thirds of the world's emitters. Think about that. And that was in 1997.

Going forward, if that policy were in effect today, it would have excluded almost 80 percent of the world's emissions. So that wasn't a good policy approach.