I want to make it perfectly clear that I believe it is incumbent on us to conduct our lives in a way that takes into account all the consequences of our actions, including the consequences to other people, and the consequences to the environment. I believe it is essential to act in ways that are sympathetic to the environment, now and in the future. I believe that the world has genuine problems and I believe they must be addressed effectively.
But I also think that deciding what constitutes responsible action is immensely difficult, and I believe the consequences of our actions are often difficult to know in advance.

State of Fear (2004)