During most of the Phanerozoic eon, which began about a half-billion years ago, there were few glacial intervals until the late Pliocene 2.75 million years ago. Beginning at that time, the Earth’s climate entered a period of instability with the onset of cyclical ice ages. At first these had a 41,000 year cycle, and about 1 million years ago the period lengthened to 100,000 years, which has continued to the present. Over this period of instability the climate has been extraordinarily sensitive to small forcings, whether due to Milankovitch cycles, solar variations, aerosols, or albedo variations driven by cosmic rays. The current interglacial has lasted for some ten thousand years, about the duration of past interglacials, and serious policy considerations arise as it nears its likely end. It is extremely unlikely that the current rise in carbon dioxide concentration–some 30% since 1750, and projected further increase over the next few decades–will significantly postpone the next glaciation.
Climate Stability and Policy: A Synthesis (PDF)
A shorter version appeared in Energy &Environment VOLUME 22 No. 8 2011 (PDF)
A related Op-Ed: THE COMING OF A NEW ICE AGE (PDF)
USA Today Magazine (January 2008) Goracle PDF
“We are about to waste an enormous amount of money and effort on carbon mitigation without lowering CO2 emissions one whit. The Goracle and his fellow travelers will carry the day.”
AL GORE won an Academy Award for his skillfully done film, An Inconvenient Truth. It was well-deserved. Had he given as good a performance during his campaign for president, he would have won in a landslide. As environmental drama, it only can be compared with Michael Crichton’s novel, State of Fear. Both have elements of scientific and political fact, and both are excellent fiction.
The sun’s role in the earth’s recent warming remains controversial even though there is a good deal of evidence to support the thesis that solar variations are a very significant factor in driving climate change both currently and in the past. This precis lays out the background and data needed to understand the basic scientific argument behind the contention that variations in solar output have a significant impact on current changes in climate. It also offers a simple, phenomenological approach for estimating the actual–as opposed to model dependent–magnitude of the sun’s influence on climate.
(arXiv: physics.ao-ph 0706.3621)
Scientific American (December 2005)
Coauthors: William H. Hannum and George S. Stanford
Reprinted in Oil and the Future of Energy by The Editors of Scientific American Magazine (The Lyons Press, 2007), p. 98.
Fast-neutron reactors could extract much more energy from recycled nuclear fuel, minimize the risks of weapons proliferation and markedly reduce the time nuclear waste must be isolated. (PDF)
This Critique builds on A Global Warming Primer. Like the Primer, its purpose is to help the reader determine whether our understanding of the earth’s climate is adequate to predict the long-term effects of carbon dioxide emissions from the continued burning of fossil fuels, to permit informed public policy decisions. This is a limited critique, looking only at a few topics covered in the latest report of the Intergovernmental Panel on Climate Change (IPCC).
The purpose of this primer is to help the reader determine whether our understanding of the earth’s climate is adequate to predict the long term effects of carbon dioxide released as a result of the continued burning of fossil fuels.