James Hansen, NASA’s senior climate scientist, was remarkable at a Science Museum dinner prior to the Nobel event in St. Peter, and he was even better at the Nobel event itself. His was the only speech that elicited a standing ovation of the audience estimated at 6500. He methodically and unassumingly showed the crowd how the human forcing of the climate dwarfs all other possible effects. His tour of the science looked at 65 million years of climate history,  a heck of a lot longer that the 400,000 years we are accustomed to seeing in the comparisons of temperature and CO2 that Al Gore has made so famous.
 
He calmly explained a variety of climate forcings that even the most serious lay student of climate science doesnt likely know:   solar variation, the albedo of the earth, the weathering of mountains and the resulting carbonate deposit to the ocean floor, the return path of carbon to the atmosphere through the subduction of tectonic plates, the 41000 year cycle of earth “wobbling” on its axis by about 1%.  He showed enough climate history that it was clear that the gradual cooling over millions of years caused the freezing of the poles at about 500 ppmv. It was a tour de force.
 
His summation of the science is that the dominant ”mechanism for change is atmospheric concentrations and surface albedo, both of which are totally in human control”.
 
Key message was that even one more decade of ‘business as usual’ will make it impractical to keep future warming to less than 1 degree C. He holds out two future scenarios:
 
(1) business as usual which commits us to an estimated 3 degrees C, and likely extinctions of 25%-50% of all species, and the serious risk of several meter sea level rise if rapid change causes the loss of Greenland or west Antartica ice caps;
(2) a “technically possible” alternative scenario of stabilization at or below 450 ppmv, with risk of loss of about 10% of species, and greatly reduced risk of catastrophic sea level rise.
 
He does a good job focusing on just these two impacts: species and sea levels. He shows that the last time that the earth was warmer by 3 degree C, the oceans were 25 meters higher. He shows that when there was warming of 5 degrees C, there were 90% species extinctions. Although he admitted that even stabilizing as low as 450 ppmv now “is surely dangerous”, there is still hope and “there is still time”.
 
The downward slope of declining emissions is daunting to achieve a concentration of 450 ppmv, but we should commit to it globally because we have little choice. He admirably handled the inevitable ’China question’.  His key policy prescriptions (disclaimer here: not approved by his employer, and his opinion alone):
 
1. an end to construction of coal plants that do not capture and sequester all emissions, and the agreement to “bulldoze” all existing coal plants for new technology “within decades”;
2. a gradually rising price on carbon through a mechanism that is fair and apolitical and economically sound;
3. reward for utilities to refocus their core business on energy efficiency
 
He lamented that scientists are such poor communicators. He warned that ‘captains of industry’ are expert communicators, and now understand the importance of “saying all the right words”, but that we should watch actions not words. “The truth is that we have the ability to solve the problem.”
 
I wonder if it was clear to many in his audience that just the prior week, the municipal utility of the City of St. Peter was one of many utilities that dropped out of the Big Stone coal plant consortium, but many utility partners seeking to build a old-fashioned coal plant soldier on.

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This entry was posted on Tuesday, October 16th, 2007 at 3:39 pm by Fresh Energy and is filed under Energy. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.