The economics of climate change mitigation

From a climate science discussions thread:

Quote:

Originally Posted by Reality Check (Post 10728572) China To Spend $6.6 Trillion To Meet Greenhouse Gas Reduction Goals is a bit of science with a lot of politics. The political part is the timing of the announcement to be just before the United Nations' climate negotiations and the commitment to climate change mitigation that the spending implies. The science part is how the money is going to be spent to reduce CO2 emissions which has not been detailed yet. The Atheist: Can you cite the mathematics to back up "mathematically it doesn't stack"? ETA: The estimates that I have seen are costs of ~1% reduction of global GNP, e.g. According to estimates presented by the 2006 Stern Review, climate change could cause a 5 percent reduction in the global GNP, whereas only 1 percent of global GNP would be needed to stabilize greenhouse gas emissions. The article does not state a timescale for that 6.6 trillion spend but Earlier this month, Chinese Premier Li Keqiang reaffirmed the government's commitment to hit a carbon emissions peak by "around 2030." which is 15 years away or 0.44 trillion dollars a year. In 2013 China's GNP was 16 trillion dollars as far as I can find out. Thus I get about 3% of China's GNP being spent on CO2 emission reduction - well above that which is thought to be needed. ETA: I suspect that the timescale goes past 2030 since China should not stop spending money on CO2 reduction as soon as they stabilize. But these numbers suggest that they can do this for the next 75 years and still spend more than enough of their GNP annually to achieve the goal of stabilization.

Any economist here to check out this rough calculation?

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