It is one thing to impose drastic measures and harsh economic penalties when an environmental problem is clear-cut and severe...

A good scientist is a person in whom the childhood quality of perennial curiosity lingers on. Once he gets an answer, he has other questions.

In my more than 60 years as a member of the American scientific community, including service as president of both the National Academy of Sciences and the American Physical Society, I have never witnessed a more disturbing corruption of the peer-review process than the events that led to this IPCC report.

Things that people learn purely out of curiosity can have a revolutionary effect on human affairs.

Research data on climate change do not show that human use of hydrocarbons is harmful. To the contrary, there is good evidence that increased atmospheric carbon dioxide is environmentally helpful.

Individual curiosity, often working without practical ends in mind, has always been a driving force for innovation.

It is one thing to impose drastic measures and harsh economic penalties when an environmental problem is clear-cut and severe....It is foolish to do so when the problem is largely hypothetical and not substantiated by observations....we do not currently have any convincing evidence or observations of significant climate change from other than natural causes.