But more than 15 sections in Chapter 8 of the report-the key chapter setting out the scientific evidence for and against a human influence over the climate-were changed or deleted after the scientist charged with examining this question had accepted the supposedly final text.

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

The trouble is that you won't get the scientists to agree on a course of action. It is almost instinctive in science to accept contrary views, because disagreeing gives you guidance to experimental tests of ideas - your own and those offered by others...

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.

Essentially all civilizations that rose to the level of possessing an urban culture had need for two forms of science-related technology, namely, mathematics for land measurements and commerce and astronomy for time-keeping in agriculture and aspects of religious rituals.

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.

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.