[Elfan]

The Copenhagen Consensus looked only at a 5 year window. Since most of the likely costs of climate change take place farther in the future it is unsurprising that they found so little benefit for mitigation.

While economic analysis is very important in this case it is also very difficult. You can get any result you want be fiddling with the discount rate.

[sethjohn]

There was no '5 year window', but the discount rate was a subject of much debate. Actually, to get climate change out of last place, they had to apply a much smaller discount rate than for any other subject.

I would argue that the consequences in breakdown of African civil society due to a continuing AIDS epidemic will have a similarly long-term consequences as climate change...and thus a similar discount rate should apply to both.