Suspend disbelief for a moment and just assume that man-made CO2 causes global warming...
And assume that California's Global Warming Solutions Act (AB 32) goes into effect and is not delayed by the increasingly impoverished citizens of California... what would the cost/assumed benefits ratio be?
Let's do a back-of-the-envelope calculation, since it apparently wasn't done by California legislators:
- USA accounts for 19.3% of global anthropogenic CO2 emissions
- California has 12% of the US population
- Percent reduction of California anthropogenic emissions by 2020 (AB 32 goal): 25%
- Global CO2 man-made emissions (2006): 30.2 billion tons
Thus, if AB 32 meets its goal of reducing California CO2 contributions 25% by 2020 (unlikely), the California reduction of global man-made CO2 emissions would be approximately:
30,200,000,000*.193*.12*.25= 174,858,000 tons
- Global man-made CO2 emissions since 1/1/60 are 1 trillion tons
- Global warming since 1/1/60 is claimed to be ~0.5°C
- The IPCC assumes almost all (97%) global warming is due to man-made CO2 and that man-made CO2 remains in the atmosphere hundreds to infinite years
Thus, global warming per ton of man-made CO2 would be 0.5/1,000,000,000,000 = 0.0000000000005°C per ton
Thus, the "global warming avoided" due to AB 32 would be 174,858,000*.0000000000005 = 0.000087429°C (about 9 hundred thousandths of 1 degree)
and since the cost of AB 32 (direct & indirect) is at least $116 Billion, the cost to "avoid global warming" per 1°C would be $116,000,000,000/.000087429 = $1,326,790,881,744,043 ($1.3 Quadrillion per degree). Note: Global GDP (61.1 trillion) is less than 5% of this amount. Looks like the cost/(assumed benefits) ratio is rather high, even if you are a true believer.