No one can truly say whether we will achieve fusion in a way that is commercially practical. If teams of PhDs have spent over 60 years wailing on the problem while spending tens of billions of dollars, I think it’s safe to use our fusion quest as the definition of hard. It’s a much larger challenge than sending men to the Moon. We have no historical precedent for an arduous technological problem on this scale that ultimately succeeded to become a ho-hum commercial reality. But for that matter, I don’t think we have any precedent for something on this scale that has failed. In short, we’re out of our depths and can’t be cocky about predictions in either direction.I certainly remember fusion being presented as the future energy source already as a child. I remember Swedish scientist Hannes Alvén's groundbreaking research to make "magnetic bottles" to contain nuclear fusion, as I was a technological optimist as a child of the Moon landing age.I don't really believe much in fusion these days.
I don't know, and can't judge if failure of a fusion plant is potentially as lethal or even worse than a failure of a fission reactor, but I am told fusion should be less dangerous. I guess we will not know for sure until it is a bit too late. I certainly believe that it will be very difficult to ever get fusion to work. And even if it could work, the development of technologies like that are based on an assumption of eternal stability of society, and an eternal complex society which can afford to allocate resources to enormous investments and research for eons of time. And security. And stability. Nuclear power and fusion pre-suppose eternal stability of society which - unfortunately - is utterly ahistorical. There will be chaos, there will be Gaddafis and Osamas, there will be social unrest. As one commenter to Tom's post says: "Sometimes overwhelming complexity is mother nature’s way of saying you’re going down the wrong path."
These kinds of technologies are fueled by big government spending and ambitious researchers. Two secondary, but still serious problems with it are that it divert resources and brilliant brains from more promising and simpler solutions, and that it keeps people dreaming that we will find another bag full of candy, similar like the fossil fuel boon, that allowed us to, seemingly, detach from natural boundaries.
And even if it could work, which I don't think it will, and even if it would be a very efficient and cheap source of energy, which is much less sure (the costs for this is very high, and energy efficiency is extremely low so far), I don't think humanity will benefit much from another candy bag. Cheap energy is the prime driver to exhaust all other resources. We don't need more of that, as little as we need more sugar or fat in our diet. And yes, those two things are related, but that is the subject for another post.