A reader comments on the latest model sensitivities of climate change:
4.5ºC is 8.1ºF. That might not seem big, but imagine how many Joules of energy that is. Wikipedia says the total mass of the atmosphere is 5 x 10**18 kilograms. The number Joules to raise 1 kilogram of air by 1 degree Celsius is 1005. Of course, when we warm the atmosphere down here near the surface by 1.5ºC or as much as 4.5ºC, we’re not warming the entire 5E18 kilograms of it, though 80% of the gasses are in the bottom 10 miles. So just for grins, let’s estimate how much energy it takes just to raise the bottom one-fifth of the troposphere, the layer of the atmosphere closest to the earth and where weather occurs. The the troposphere is roughly 7 to 20 kilometers thick (thicker at equator), or about 4.3 to 12.4 miles. Let’s take an average of 7 miles just to be on the conservative side, and estimate that it contains 7 miles divided by 10 miles times 80% of gas mass, which is probably low as the bottom is thicker than the top at any altitude. But it gives us 2.814 x 10**21 Joules. How big is that? About 36 times all of the electricity generated world wide per year (or 36 years worth at 2015 production levels). Or like about 13,400 of the largest-ever tested atomic bombs (USSR Tsar Bomba at 50,000 kilotons or 220,000 terrajoules — much larger than the average nuke, 3+ times larger than largest USA nuke test). That much energy is bound to do something. And the above is for just 1ºC increase, grossly underestimating the mass parameter of the atmosphere.
