Ah, thank you!
So rather than try to rebut this myself, I'll let someone qualified do it:
http://www.lse.ac.uk/GranthamInstitute/wp-content/uploads/20...
And also:
https://thinkprogress.org/bjorn-lomborgs-new-paper-appears-t...
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.
Wikipedia isn't very nice to him either: https://en.wikipedia.org/wiki/Bjørn_Lomborg#Formal_accusatio...
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...