I know a lot of people will ask, why a technological solution to problems technology caused? We can have a agrarian utopia with what nature providers, sunshine, wind, water, good earth.
I don’t wish to interfere with anyone who has that vision. They are welcome to purchase land, farm it in a sustainable manner, live with whatever level of technology they choose. I do believe the rest of us have an obligation to not pollute the planet so for those people who wish to live in that manner it is possible.
However, millions of people are living on land now that can’t support them, in Africa in particular. For those people to have a decent lifestyle they need to be part of a larger system involving trade, so that they can trade things they can make or do for food which they can not, on their land, produce in adequate quantities.
In order to bring those people out of poverty, the world economy needs to expand further; that can only happen with an expansion of the energy supply. If we expanded the energy supply by burning more hydrocarbons we’d hasten the demise of our ecosystem. We need a clean expandable energy source.
Expandable is a key word here, the density of solar power limits the degree to which it can be expanded. I have no doubt that solar and wind together could provide for our current energy consumptions with the appropriate infrastructure. However, by the time China and India scale their economies up to a level where their citizens can have a decent standard of living, and then also Africa, I do not feel as comfortable that these sources will scale adequately.
We are using water from the water table faster than it is replenished by nature. Soon, it will be necessary to desalinate and pump huge quantities of water in order to maintain the agriculture upon which we are dependent for food. Even with no economic expansion this will require large amounts of energy.
If not fusion, then I think we will be forced to rely on fission. Nuclear fission could be done cleanly and could provide power for millions of years through a combination of fast flux breeder reactors, on-site reprocessing, extraction of uranium from seawater, and the use of thorium fuel. With all the actinides re-used in fast-flux breeder reactors, there would be no actinide wastes, only fission products which decay to the same levels as they were when we mined the ore in 500 years, a much more short-term problem than the existing one-pass fuel cycle used here in the United States.
If we do not make either of these options happen, then I think we will doom many humans to poverty and starvation and I’d rather not see that happen, and of those two options fusion is infinitely cleaner and safer. There is zero possibility of a runaway reaction with fusion. There are no nuclear wastes produced as products of the reaction though with neutronic fuels there is some neutron activation of reactor structures so those will need to be dealt with when the reactor is dismantled. Even so that’s a trivial waste burden compared to fission reactors and most designs call for a lithium blanket to absorb most of the neutrons to breed tritium and shield reactor components simultaneously. Aneutronic fuels eliminate this issue entirely.