John Christy, director of the Earth System Science Center at the University of Alabama and a participant in the U.N.'s Intergovernmental Panel on Climate Change, wrote a piece in the Wall Street Journal (11-1-07) that made some interesting observations about efforts underway to reduce CO2 emissions. I'll just quote him here:
"California and some Northeastern states have decided to force their residents to buy cars that average 43 miles-per-gallon within the next decade. Even if you applied this law to the entire world, the net effect would reduce projected warming by about 0.05 degrees Fahrenheit by 2100, an amount so minuscule as to be undetectable. Global temperatures vary more than that from day to day.
Suppose you are very serious about making a dent in carbon emissions and could replace about 10% of the world's energy sources with non-CO2-emitting nuclear power by 2020 -- roughly equivalent to halving U.S. emissions. Based on IPCC-like projections, the required 1,000 new nuclear power plants would slow the warming by about 0.2 degrees Fahrenheit per century. "
He goes on to say that spending on health issues such as micronutrients for children, HIV/AIDS and water purification has benefits 50 to 200 times those of attempting to marginally limit global warming and, that, "Given the scientific uncertainty and our relative impotence regarding climate change, the moral imperative here seems clear to me."