> If we're going to 'solve' global warming, we really need fusion ASAP. It truly is a silver bullet for this problem and will also be the key to colonizing Mars

> If we're going to 'solve' global warming, we really need fusion ASAP. It truly is a silver bullet for this problem and will also be the key to colonizing Mars. Not at all. People have this impression that fusion produces much more energy than fission. That's not the case. Fission produces about 200 MeV per single fission event. Since the nucleus that splits is either U-235 or Pu-239, that is about 1 MeV per nucleon. Fusion produces in the range of 1 MeV to 23 MeV per even. There are numerous possible reactions, from Deuterium-Tritium to Hydrogen-Nitrogen. At most you get about 4 MeV per nucleon (for the Deuterium-Tritium and Deuterium-Helium3). In most cases you get less, even in some cases less than 1MeV per nucleon. So, at most fusion is about 4 times more efficient than fission. But in those cases when this happens, one of the reactants is something that we can't find in nature (either tritium or He3), so we need to make out of other nuclear reactions. Tritium in particular is something regularly discarded by fission reactors. The problem is that if we ever develop Deuterium-Tritium fusion, our fission reactors will not generate anything close to the needed Tritium, not by 2 orders of magnitude. This is just to dispel the illusion that if we unlock fusion, we get loads more energy than from fission. Now, it will be cleaner. It will not produce nuclear waste. But nuclear waste is not really the big issue that the anti-nuclear crowd makes it to be. The problem with fusion is this: we need two miracles to happen. We need to make fusion happen, and then we need to make it economical. With fission, we only need the second miracle.