I haven't looked at this specific calculation, but at the current levels of CO2, which won't go down in 100 years, Earth will reach a temperature equilibrium about 2°C higher than now.
Unless our science is totally wrong, without environmental engineering, it must be relative to business as usual.
I think that 2nd critique is spot on. I tried reading his paper yesterday and thought the graphs looked rather strange, with weird transitions in 2030, when he assumed all CO2 reduction efforts would stop.
Unless our science is totally wrong, without environmental engineering, it must be relative to business as usual.
And here is the source of the claim: http://onlinelibrary.wiley.com/doi/10.1111/1758-5899.12295/f...