In the long term we have to get away from fossil fuels, not because there isn't plenty of carbon to burn and not because even doubling the CO2 in the atmosphere would not represent the existential crises the money changes would like you to believe it is, but because the nature of all extractive technologies is that they become increasingly expensive because first you go for the most concentrated and easy to get at ores and as you exhaust those you go to increasingly diluted and increasingly difficult to get at ores, and because our future prosperity depends upon being able to continue to increase our use of energy.

Wind and solar are not viable replacements because they are dilute and intermittent. They require way too much land as well as too many exotic and difficult to recycle materials and at the same time they do not provide the reliable energy we need. They can to some degree be a part of the mix but they can not replace fossil fuels.

Two renewable sources of energy which can to a degree are hydroelectric and geo-thermal, but hydro-electric is already largely tapped out and geo-thermal is expensive except in a handful of locations where heat is very near the surface. But new drilling techniques may change this and even now there are locations where heat is very near the surface, such as Yellowstone, that we could but are not tapping.

The most viable short-term energy source is nuclear fission, and in the longer term nuclear fusion but the technology for nuclear fusion is not yet viable and the way we are currently doing nuclear fission would be a disaster if we scaled it as is, however there is a solution to all of nuclear problems in form of molten salt breeder reactors. Molten salt reactors, in general, are inherently safe and do not pose any of the dangers of boiling or pressurized water reactors. The fast spectrum breeder versions of these reactors further can burn much more abundant fuels such as U-238 or Thorium-232 which in breeder can be bread into Pl-239 or U-233 which is fissionable. A fast spectrum breeder reactor can also burn up ALL of the actinide (heavier than Uranium) waste from existing reactors, and this is the stuff that is a long term hazard, the fission products represent about a 300 year problem and if you burn up the actinides this is all you have left.

Further because the fuel is liquid in these reactors and fission products are extracted in real-time, many medically and industrially useful short-lived radio-isotopes can be extracted. And because the fission products are continuously removed, they do not poison the reaction so the reactor can be continuously fueled, ever requiring downtime for re-fueling, and because they are removed, when the reaction is shut down, there is not ongoing heat production from their decay, unlike water based reactors.

Because these reactors do not use water as a coolant, they do not need to be located near large bodies of water. Because they aren't pressurized, they do not need an expensive containment vessel, and because the physics make them self-regulating there is no danger of a run-away reaction or of anything disasterous happening if either cooling is lost or control is lost. If we are going to scale nuclear energy, and I don't believe we really have a choice, then fuel use efficiency, not generating million year waste we can't contain, and inherent safety is something we NEED to have in our reactor fleet.