Andrew Revkin quotes Judith Curry (who declined to be a co-author on the BEST results being announced today):
Their latest paper on the 250-year record concludes that the best explanation for the observed warming is greenhouse gas emissions. Their analysis is way oversimplistic and not at all convincing in my opinion.Physicists tend to see the world as made up of simple physical systems (particles and fields), and when the physical systems get too complicated (atoms beyond Helium, molecules, galaxies), they hand them off to the chemists and astronomers for analysis. Heisenberg et al found the laws of quantum mechanics; but then they didn't get much beyond calculating the spectra of He2+ before saying, yeesh, that's hard, enough of that! So they turned to the structure of the nucleus and the laws of quantum electrodynamics and partied it up there.
There is broad agreement that greenhouse gas emissions have contributed to the warming in the latter half of the 20th century; the big question is how much of this warming can we attribute to greenhouse gas emissions. I don’t think this question can be answered by the simple curve fitting used in this paper, and I don’t see that their paper adds anything to our understanding of the causes of the recent warming. That said, I think there are two interesting results in this paper, regarding their analysis of 19th century volcanoes and the impact on climate, and also the changes to the diurnal temperature range.
What does x-ray crystallography say about the structure of DNA? Don't ask a physicist! Pure physicists don't do that kind of stuff. Sure, they could if they really wanted to. But by and large they really don't want to, and it's not what they're good at.
Attributing climate is more like figuring out the structure of DNA than it is like figuring out the laws of quantum mechanics -- simple curve-fitting ("exponentials, polynomials") doesn't cut it. In fact, it makes you look kind of foolish. If it were that simple climatologists would have done it in the 19th century (and, of course, they've all tried curve-fitting on the second week of their research, then hid those papers in a bottom drawer.) That's exactly why they scratch around for all the clues they can get, and why they ruin their youth build climate models. (Sure, CO2 is one of the big factors, which is already enough to be worried about our large emissions; but there is usually a lot going on.)
BEST did a great job reconstructing the temperature history of the planet (assuming their work passes peer review, at least). Perhaps they should have stopped there.