Chairman Whitehouse, Ranking Member Inhofe, and members of the Committee. Thank you for the opportunity to testify at today’s hearing.
In 1971, as a PhD student in ecology I joined an activist group in a church basement in Vancouver Canada and sailed on a small boat across the Pacific to protest US Hydrogen bomb testing in Alaska. We became Greenpeace.
After 15 years in the top committee I had to leave as Greenpeace took a sharp turn to the political left, and began to adopt policies that I could not accept from my scientific perspective. Climate change was not an issue when I abandoned Greenpeace, but it certainly is now.
There is no scientific proof that human emissions of carbon dioxide (CO2) are the dominant cause of the minor warming of the Earth’s atmosphere over the past 100 years. If there were such a proof it would be written down for all to see. No actual proof, as it is understood in science, exists.
The Intergovernmental Panel on Climate Change (IPCC) states: “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” (My emphasis)
“Extremely likely” is not a scientific term but rather a judgment, as in a court of law. The IPCC defines “extremely likely” as a “95-100% probability”. But upon further examination it is clear that these numbers are not the result of any mathematical calculation or statistical analysis. They have been “invented” as a construct within the IPCC report to express “expert judgment”, as determined by the IPCC contributors.
These judgments are based, almost entirely, on the results of sophisticated computer models designed to predict the future of global climate. As noted by many observers, including Dr. Freeman Dyson of the Princeton Institute for Advanced Studies, a computer model is not a crystal ball. We may think it sophisticated, but we cannot predict the future with a computer model any more than we can make predictions with crystal balls, throwing bones, or by appealing to the Gods.