What Obama’s new science adviser has to say about climate change
Ben Smith digs up two pieces from Obama’s new science adviser, John Holdren. The first, from the Bulletin of the Atomic Scientists, titled “The Sky Is Falling,” requires a subscription (though perhaps the title says enough).
And here’s a piece titled “The Future of Climate Change Policy: The U.S.’s Last Chance to Lead,” from Scientific American in October. An excerpt:
The ongoing disruption of the earth’s climate by man-made greenhouse gases is already well beyond dangerous and is careening toward completely unmanageable. Under midrange projections for economic growth and technological change, the planet’s average surface temperature in 2050 will be about two degrees Celsius (3.6 degrees Fahrenheit) higher than its preindustrial value. The last time the earth was that warm was 130,000 years ago, and sea level was four to six meters higher than today. No one knows how long it will take sea level to “catch up” with such an increase; it could be several centuries, or it could be less.
Even with uncertainties, there is reason to believe that tipping points into unmanageable changes will become much more probable for increases larger than two degrees C. To achieve a better-than-even chance of not exceeding that figure, human emissions must start to decline soon, falling to about half of today’s level by 2050 and further thereafter.
Carbon dioxide (CO2) is the most important of civilization’s emissions and the most difficult to reduce. About 80 percent comes from burning coal, oil and natural gas; most of the rest comes from deforestation in the tropics. The largest emitters in 2006 were (in descending order) the U.S., China, Indonesia, Brazil, Russia, India, Japan and Germany. (Numbers are not final, but China appears to have passed the U.S. in 2007.)
There is no way to keep the temperature increase under two degrees C unless these big emitters start taking serious action almost immediately. The U.S. and the other industrial nations on the list have an obligation to lead this transition. They have caused most of the buildup of gases to date, and they have the largest per capita emissions, the greatest wealth and the most technology. And they agreed to their responsibility to lead in the United Nations Framework Convention on Climate Change of 1992, to which the U.S. and 191 other countries are parties.