This past Monday, James Hansen spoke at UC Santa Barbara. His lecture slides are available on-line; the lecture is not, but let me put down some of his more memorable quotes.
After noting the size of the crowd–over 1,000 people, buzzing with anticipation–he said he was happy to see a large crowd, including many students, but added:
I’ve always been a little puzzled why young people don’t get more disturbed by this issue since you’re getting the short end of the stick.
He said that although estimates are difficult, scientists agree that a "business-as-usual" (BAU) scenario in which little or nothing is done to reduce carbon emissions will lead to what some scientists call a "reduction of biological diversity," which is a "euphemistic way" to describe the loss of species. No one knows exactly how many species will be lost, but in the last big climate change event, the Palocene-Eocene Thermal Event of 55 million years ago, when temperatures rose 5-8 degrees Centrigrate over a few thousands years, an estimated 90% of species died. He added:
We will save the polar bears in zoos, but this may not be considered by the bear to be "saving" –it may be more like jails.
Regarding estimates of the melting of the Greenland Ice Sheet and the West Antarctic Ice Sheet, he was critical of the just-released Fourth Assessment of the IPCC, which estimates only a slight increase in the rate of melt, in the range of a total of a foot or two this century.
I can’t imagine how the West Antarctic and the Greenland ice sheet could survive a Business-As-Usual scenario if they were covered with summer ice melt. We know from earth history that about fourteen thousand years ago [Meltwater Pulse 1A] the sea level rose 20 meters in 400 years. New Orleans is a village compared to what could happen in China, where 250 million people live nearly at sea level.
Regarding our climate in the Western U.S., he said:
Because we expect a decrease in annual rainfall and because temperatures will be going up, it’s going to be hotter and drier. I think we’re beginning to see the first small steps towards this already, as globally averaged temps have climbed about 1 degree in the Western U.S. Super-Droughts will be possible if we follow a Business-as-Usual scenario.
Regarding energy production, he spoke caustically of huge plans to transform tar sands production in the mountain states and British Columbia:
We simply can’t cook the Rocky Mountains and drip oil out of them without producing a completely different planet.
Speaking of the public relations challenge of global waming, he said:
I don’t think we scientists have done a very good job of making clear the threat of producing a different planet under a business-as-usual scenario.
He added, with a touch of asperity, that he was a government employee, and:
My comments are my personal opinions and I am today not representing the government.
The crowd laughed. Nearly everyone knows how little Hansen is liked in the Bush adminstration.