We've noted one effect of the recent beastly heat in the Midwest: the global warming curmudgeons--the ones who, when it hits 20 below in the winter are saying things like "Where's Al Gore now?" have largely been observing a circumspect silence on the topic.
I have been debating with one of my friends on this topic--neither of us is budging--but, for the hell of it, decided to publish some of the figures I noodled up on my own.
To quote Wikipedia, "Earth's average surface temperature has increased by about 0.8 °C (1.4 °F), with about two thirds of the increase occurring since 1980. Warming of the climate system is unequivocal."
The question I asked myself is, how much energy does this require? How much more energy has been trapped in the atmosphere to cause this raise in temperature?
Now, for what follows, I know that "earth's surface" and "earth's atmosphere" aren't necessarily equivalent. However, I don't know how the earth's surface measurement is calculated. On the other hand, similar discussions are put in terms of the atmosphere, so I decided to look at that.
How much energy would be required to raise the temperature of earth's atmosphere .8 degrees Centigrade?
Earth has approximately Earth has approximately 4.2 billion cubic kilometers (4,200,000,000,000,000,000 cubic meters) of atmosphere. Amount of energy required to raise the temperature of one cubic meter of air one degree centigrade: 1211 joules. Therefore, the amount of energy required to raise the temperature of the earth's atmosphere .8 degrees C (4200000000000000000 x 1211 x .8) = 4,068,960,000,000,000,000,000 joules required.
By contrast, one megaton equivalent of TNT releases 4,200,000,000,000,000 joules. According to web sources, there are approximately 36000 nuclear weapons in the world's arsenals. Exact megatonnage available is unknown, but I have chosen to use an average yield of 5 megatons, which would be a generous estimate since many of the weapons stockpiled are "tactical" weapons of relatively low output. Given that estimate, the energy released by detonation of the world's entire nuclear arsenal would yield 180000 megatons, or 756,000,000,000,000,000,000 (7.560000000e+20) joules. Thus it would require the detonation of at least 5.38 times the total nuclear arsenal of the planet to put an equivalent amount of energy into the earth's atmosphere.
The earth's atmosphere is a chaotic system. What happens when you put more energy into a chaotic system? It becomes more chaotic, rather than, as the simplistic view might expect, becoming uniformly warmer. Therefore, we can expect higher highs, lower lows, and more extreme weather events, which is precisely what we have been observing.
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