Nuclear
I see that nuclear is gaining a bit more traction lately - or maybe the publicity is being built up to generate a perception of new respectability for nuclear.
I am unconvinced, at this time anyway, that any nuclear is safe, whether it be thorium, uranium or waste material. At this time I believe it is correct to say that the technology is still short of what is needed.
I am concerned that nuclear is so easily portrayed as a "fix" for our energy issues. Fully deployed, it will certainly reduce our need for fossil-fuelled power generation - but if the lead time for say a "new" reactor is 15-20 years, wide scale deployment of the new reactors will take years. I was told once (sorry no source) that right now we would need ~100,000 nuclear reactors to totally displace coal. Sound a lot, and since I don't have a source, let's just say we need half that number. How many can we build per year? Can we build enough to slow down carbon dioxide sufficiently? I have my doubts. And if I am right, that logistically we are too late, nuclear is not a fix. We are betting on technology that has yet to be proven, so don't relax yet.