Oh, wait. For a minute there I thought I was guest blogging the inverse-paper at Watts Up With Climate Depot?
Seriously though, this paper is good news, but not as good as you'd want. It shows that we will probably avoid the higher end range of temperature change, and have more time to address the CO2 problem and get it right. But not a lot more time.
I threw together a little spreadsheet (we all know the best science is done on a Friday night with a spreadsheet) that simply assumes atmospheric CO2 levels keep increasing the way they have been: at a yearly rate that was about 0.30%/yr in 1970 and is 0.55%/yr now, and I just linearly interpolated that into the future. Remembering to carry the 4 and avoid using the Comic Sans font, I got the following for the number of years warming delayed with a climate sensitivity (S) of 2.3 K vs 3.0 K:
In other words, the warming that would have occurred in 2100 under a S=3.0 K scenario would occur in 2115 under a 2.3 K scenario. Etc.
The lead author, Andreas Schmittner (who is at Oregon State University) told the Oregonian:
"I think we should be worried, but we should not be desperate," said Andreas Schmittner, an Oregon State University researcher and lead author of the study, published online today by the journal Science. "It's not already too late to do something. We still have time to figure out a solution."And, of course, this paper has no consequences for the problem of ocean debaseification (or what regular people call ocean acidification).
However, in an accompanying Perspective in Science, Gabriele Hegerl and Tom Russon don't sound especially convinced:
The work of Schmittner et al. demonstrates that climates of the past can provide potentially powerful information to reduce uncertainty in future climate predictions and evaluate the likelihood of climate change that is larger than captured in present models. However, given the remaining uncertainties, which the authors discuss in their paper, a firm upper boundary is still elusive. The study also shows that to take advantage of the opportunity offered by past climates for understanding future climate change requires not just high quality data but also appropriate physical climate models and statistical modeling. This is not an easy challenge, but it is an important one.