We would need a virtual decarbonisation of the power sector. Given the growing demand for electricity, this would mean that on average per year 35 coal and 20 gas-fired power plants would have to be fitted with CO2 capture and storage (CCS) technology, between 2010 and 2050 at a cost of USD 1.5 billion each. Furthermore, we would have to build an additional 32 new nuclear plants each year and wind capacity would have to increase by approximately 17,500 turbines each year, 215 million square metres of solar panels.
I will remind you that all of this is will (hopefully!) only lower emissions by 50% -- 30% lower than most experts say we need to reach to have any effect on the climate this century. The IEA calls this green-energy buildup a "formidable challenge." Seeing as the report goes on to say that we must not only construct hundreds of kilometers of solar panels each year, but must build nearly a billion electric or hydrogen fuel cell vehicles, find a sufficient number of geological stable sites for several hundred million tons of sequestered carbon and radioactive waste, double the number of engineering graduates coming out of our colleges, and change the ingrained NIMBY attitudes of the Western World in order to reach this 50% mark, I could not help but conclude that the IEA team that wrote this document has a sense of humor.
But you know, I can't really fault them for that. If it I were trying to convince multi-billion dollar organizations and skeptical governments that we need to change our entire energy supply to slow global warming, I would need a sense of humor too.