[ylem]

Great! So it's not just me! As I understand the paper, their main point seems to be that as you extrapolate out in time, you need to not just handle the physics of CO2 that is already in the atmosphere, but predict say how much populations will grow, as well as how much GDP will grow, and how CO2 emissions will be effected by that. So, say if there is an economic recession, then there will be less CO2 produced than if you predicted just say steady growth. This seems to be a case where I could see different assumptions (some reasonable) leading to different results--it's a far cry from say the breast cancer-vs skin-cancer mistake that he leads with