Since 1961, the world’s oceans have stored enough extra heat energy to meet all of the world’s power needs for 300 years (at 2008 consumption rates).
Here’s how I got to that figure.
I’ve been to a couple of climate science talks recently here in climate science central (Boulder, CO). The big topic these days is extreme weather. Warmer global climate means more heat energy in surface water and air to fuel stronger storms. What none of the scientists seemed to be able to tell me was how much more heat energy (other than “a lot” or “on the order of nuclear weapons”).
So I flipped to the 2007 IPCC report and found a disappointing figure:
The world’s oceans warmed by 0.5 degrees Celsius between 1961 and 2003.
Oo, half a degree. Big whoop. Well, you and I know that water stores incredible amounts of heat energy, and that there’s a hell of a lot of water on the surface of the Earth. So here’s a slightly more meaningful number:
14.1 x 10^22 joules or
Joules is a scientific unit for energy. That number is how much extra heat energy the IPCC estimates was stored by the oceans in the last half of the 20th century. If you convert that into nuclear weapons, it’s about
Little Boy is the ironically named atomic bomb that incinerated the people and city of Hiroshima back in WWII. Various estimates put its total energy at between 13,000 and 20,000 tons of TNT. I went with 15,000 tons of TNT. At 4,184,000,000 joules of energy per ton of TNT, that’s 62,760,000,000,000 joules per Little Boy explosion.
But getting back to the oceans. Global warming over the past half century has put as much extra heat energy into the oceans as if each person now alive in the United States detonated 7 Little Boy-class atomic bombs to heat up the water.
2.2 billion atomic bombs’ worth of energy in the oceans that the world’s hurricanes and tropical storms now have to drawn on. Is it any wonder that weather is getting extra hairy?
Put that figure in another context: the world’s ballooning and looming energy bill, part of the problem and cause of global warming. The world used about
1.504 x 10^13 watts or
15,040,000,000,000 joules per second of electricity in 2008
Divide that into 141,000,000,000,000,000,000,000 joules and you find that the extra heat energy stored in the oceans could have powered the world for 9,375,000,000 seconds, or 300 years, if we lived all those years like we did in 2008.
Hydrothermal energy, anyone?