Thanks to Eric at Classical Values I have come across some very interesting numbers about CO2.
Let us start at the beginning. Before the advent of fuel burning industry the concentration of CO2 in the atmosphere was 288 parts per million (ppm). By the year 2000 man had added 11.88 ppm to that total and nature has added 68.52 ppm to the total. Which means that if the effect is linear (it is not for reasons I won't go into here) and man has added about 15% of the CO2 that has been added to the atmosphere and the temperature rise has been about 1.1 deg F (.6 deg C). Then man made CO2 has been responsible for at most about .15 deg F (.1 deg C) of climate change. Which fits in well with Nir Shaviv's analysis, which says that solar variations accounts for .9 deg F (.5 deg C) of global warming.
That is the best case for the global warming guys. Because parts of the argument are wrong. It assumes that the whole of the warming is caused by CO2. For the sake of argument let us say that the solar contribution is 80%. That would mean that the increase in CO2 is responsible for about .22 deg F (.1 deg C) of the global warming. Man's contribution would then be 15% of that or about .033 deg F or (.015 deg C).
I wonder if any one has told Al Gore?
Cross Posted at Power and Control and at Classical Values