There’s an article I read in the March 20 issue of The Economist that I think is worth reading. A lot of people ask me about issues regarding energy and the climate, and this particular piece does a good job of presenting a pretty complete view of what scientists now know about climate change. It clarifies the uncertainties, and it also gives a context that I think might be helpful to people who are trying to understand some of the controversies.
The article makes clear why scientists now pretty much agree that greenhouse gases are building up in the earth’s atmosphere as a result of human activity. There are many different measurements indicating that carbon dioxide levels have been rising since at least the 1950s and probably since the beginning of the industrial revolution. From analysis of carbon isotopes and other things, scientists have identified industry as the source of most of this CO2. And everybody agrees that CO2 absorbs infrared radiation from the sun, which tends to produce a greenhouse effect.
The disagreements are mainly about how much warmer the climate will get. This is a tough question because the dynamics of the earth’s atmosphere are enormously complex and difficult to model accurately. Projections of future warming range from not too bad to catastrophic. Most scientists believe there’s at least a significant risk of serious warming unless we reduce CO2 emissions. In an editorial, The Economist argues that the risk is big enough to justify action.
I agree, especially because even moderate warming could cause mass starvation and have other very negative effects on the world’s poorest 2 billion people. This is one of the reasons why I’ve gotten very interested in new energy technologies that could move us toward zero carbon emissions. As I said at TED, my dream is to create zero-carbon technologies that will be cheaper than coal or oil. That way, even climate skeptics will want to adopt them, and more of the world’s poorest people will be able to benefit from the services and the improved quality of life that energy makes possible.