I'm surprised...
so few people mentioned Chernobyl with respect to nuclear power. Yes, it's very safe these days, but if something goes wrong, it goes wrong effectively forever. Not just in a small locale, either...a meltdown is a regional and *ongoing* disaster (as radioactive particulates can still come out of the area and float away, especially if repeated water flows are encountered by the pile melting downwards). The breadbasket of the Soviet Union was literally nuked in the process, and that changes the entire global trade landscape as they have to import more food each year (at added energy expense, too).
Also, nuclear disposal is not easy. The waste will be radioactive for untold thousands of years, or at least until we discover the quantum physics equivalent of a philospoher's stone (to transmute the waste into some other useful compound or elements). Not only that, *the plant itself* is radioactive. Yes, it is. After years of housing the radioactive pile, the structures around it absorb the radiation, and begin to re-radiate that radioactivity. That's why workers wear badges, not just in case of a leak. The structure itself weakens due to absorbing that much radioactivity, making it more dangerous the longer it runs. The plant's ambient radiation rises during the plant's lifespan, and when it's decommissioned, the plant has to be disposed of as well. What remains to be discussed openly is whether or not the land where the plants are currently situated have also become radioactive, and how many plants can be operated in one place before the land itself starts killing people. They may dig out the radioactive dirt as well, but then you end up digging down into the water table eventually, so the land can't last forever either.
Also, despite popular belief, nuclear plants *do* emit low-level radioactivity. This is because the water piped around the core becomes irradiated when the pipes inevitably become irradiated due to constant exposure (thus re-radiating into the cooling water). So, if you cluster reactors together, you will have clustered ambient radioactivity, much in the way that clustering cars in cities generates smog and acid rain in certain geographies. Furthermore, if you cluster nuclear plants, and one melts down, the others will probably go with it, furthering the effects of the disaster.
I won't go into the debate about terrorist attacks on nuclear plants - we have people falling asleep at the controls here in the United States, and that's bad enough.
Don't get me wrong, I'm expecting nuclear to be mandatory in the next 20 years, because telling people during the 1970's to cut back on power usage during the gas crisis did NOT work, and thus increased consumption will follow with the rise in population (and increased prices due to price-gouging by greedy bastards - kind of like today, actually). However, nuclear is by far and away a bad, bad idea. I try to use my brain in my down-time to figure out how to bridge the gaps between conventional and quantum physics in order to try to create an insane idea for a better energy technology. However, so far I've had no luck. So, expect what you see coming. You won't be able to escape it unless one of you can come up with a new way to manipulate physics to generate power.
If you don't, you have only three options:
1. World War 3 sending us into the Third (and final) Dark Age in a vain effort by nuclear-weapon-wielding powers to grab what's left of the world's dwindling resources. There's brinksmanship, and then there's nuclear spoilsports. "If I can't rule the world, no one can!" *BOOM*. "If we can't rule ourselves, no one can! Live free or die!" *BOOM*. "Your religion is different than ours!" *BOOMBOOMBOOMBOOMBOOM*. "You can't steal my stuff!" *BOOM* Once it starts, it's too late. Look up "Archduke Ferdinand", if you don't believe me.
2. Forced conservation and population control, leading to widespread starvation, food riots, revolutions and endless civil wars ending up in nuclear regional wars, destroying the human-habitable environment and civilization in the process (there's that Third Dark Age again).
3. Global cooperation (and I mean everyone - less than total participation means #2 above and maybe #1 as well). Not communism, not socialism, not capitalism, not dictatorship-style domination, but true cooperation as a species. A confederation-style global government, if you like. China runs its government its own way, USA does theirs, Russia does theirs, etc, and people shut up about the differences - but we all quit fighting and shafting each other, and cooperate to save *all* of us from extinction. Unless we cooperate to get out into space, the human race is toast. Get used to it. No one will suffer one country other than itself to rule the world alone.
...well, maybe there's the return of Jesus Christ, and maybe aliens will save us, but I really don't want to have to resort to those things if I don't have to. God helps those who help themselves (and each other, for that matter).
If you want statistics, try this: without food imports, 1.6 billion Chinese people must subsist on their own arable land, 1 square foot of which must sustain 7 adults. If half of the Chinese population have a child, this would raise their population from 1.6 billion to 2.0 billion. That same square foot of arable land (nine months later) must sustain *9 adults*. This means that each adult would have to consume 21% less food in order to not require imports. Now imagine that population increase *every 9 months* (one-child laws notwithstanding). Growth of this kind, or even near it, is *not* sustainable, not even for a country the size of China. That's not including India, the United States, or any other countries with booming populations. Add it up, and you'll probably see 10 billion people worldwide by 2020. Even then, the inevitable overpopulation of the planet will make the human race choose between housing and food and energy generation as every last scrap of land becomes inhabited (even Antarctica - melt the glaciers for tap water!). Throw in nuclear plant disasters making large regions unlivable (and non-arable), and you have a recipe for self-destruction (short of global cooperation). Bad, bad idea.
We need a Manhattan Project for advanced quantum physics and fusion power, I say. Once we solve those problems, we not only have power, but advanced propulsion units for feasible space travel. Bring it on, before it's too late. Hell, I'll lead the project myself. I may not know much about quantum physics, but I know damn well where I can find some people who do (and hire them). And as you can tell by my excessive verbosity, I am highly motivated.