James Hansen was the lead author of a paper recently, “Target Atmospheric CO2: Where Should Humanity Aim?“. It appears in the latest edition of the Open Atmosphere Science Journal. I just finished reading the paper when an article on it appeared on CNN’s website. I will have much more on this paper, and others I’ve read recently, in the future. In short, the article makes the argument that CO2 concentrations are already too high. To avoid a return to the early Cenozoic Period climate, humanity must act immediately. 350ppm is the target. We’re currently at 385ppm, and that’s currently going up by 2-3ppm per year.
In related news, California Governor Arnold Schwarzenegger has issued an executive order calling for a 33% Renewable Portfolio Standard by 2020. That is significant. If California were it’s own country, it would have the 7th largest economy in the world. An aggressive goal like this will lead the way for the remainder of the country to establish and improve upon renewable energy sources. California is looking at a greenhouse gas reduction goal of 1990 levels by 2020 and 80 percent below 1990 emissions levels by 2050 pretty seriously. Will it be enough? Certainly not if California acts alone or nearly alone. The U.S. needs to adopt a similarly aggressive stance. As Hansen’t paper points out, CO2 concentrations are too high already. Everything we do today to bring that concentration down is less we have to do tomorrow.