The idea of using solar to heat liquid to drive turbines makes me happy. It seems so much easier than drastic advances in material science.
Afaik, French nuclear power is the gold standard. Discussions of the cost of nuclear power should start there, not with some Cheops Law (everything takes longer and costs more) plant in Scandinavia.
Anyone have numbers about the efficiency of organic agriculture? I thought the big cost was added labor rather than more land, but this is only an impression.
Biochar (making agricultural waste into charcoal, and burying it) sounds really interesting.
Link thanks to andrewducker, who reads digg so I don't have to.