[2017: obviously incomplete, but interesting (to me) as an archive of my thinking. Unmodified from the draft below this line.]
I wasn’t very convinced by Joe Romms list. So what, global-warming-wise, is likely to kill us all?
Firstly, I can’t see direct temperature rise doing it. Even an increase by 5 oC won’t make most places uninhabitable or close to it. The 2003 heat wave, that people trot out, merely demonstrates that getting warmer than you are used to is bad. Its not hard to adapt to this; the evidence is obvious, since many countries are already more than 5 oC warmer than 2003 Europe. And it might save people dying of cold in winter.
Other direct climatic changes, most obviously changes in precipitation, could be serious. Mega-droughts, perhaps, (whatever a mega-drought might be) could have fairly serious impacts on crop production. We could survive – we all eat too much anyway – but it would be destabalising. Suppose you gave the average overweight stereotypical US denizen the choice of using half the energy or eating half the food: which might they choose? Well obviously they’d choose someone else to make the sacrifice. PD has some nice comments about water use.