Something I'd read ages ago, updated here by the always-estimable Martin Wolf of the FT, and commented by Naked Capitalism.
If there is a crunch or three coming along (energy use, global cooling cos' of Chilling Stars, various tragedies of the commons), we humans won't react all that well. Fights. Wars. The line which best sums it all up:
"People fight to keep what they have more fiercely than to obtain what they do not have. This is the “endowment effect”.