Is it just me or does anyone else think that a great contributor to global warming is the method with which we create and consume power. We produce most of the electricity with steam and that steam needs to cool off before it can become steam again. They way that steam is cooled is either with water or surrounding air. Every nuclear reactor needs to be next to a river if the outside air is not cold enough. The river on which our reactor is built is 4C hotter after it passes the power plant because it's used to cool the steam. And that temperature increase is constant, all the time. Coal power plants do the same. Then, on the consumer side, we also convert much of that electricity into heat, with inefficient light bulbs, cars (thats why the engine needs a heatsink and a fan), electronic equipment, etc... If your computer uses 150W, thats 150W of heat output per hour. Human body outputs on average ~100Wh.