…there is a post that will be of great interest to you at Judy Curry’s blog. The conclusion is that the atmospheric sensitivity to a doubling of carbon dioxide concentration is 1.6°C. As you know, my guesstimate is 1.5°C, so it is very similar to the figure I use. If those values are indeed correct, it means that GW is not a major problem.
And, here’s more…
There is a new paper out that says (paraphrasing), “the more you know about science, the less you believe in global warming.” I read the paper (so you don’t have to) and while the authors have a large survey sample as these things go, the paper suffers because the authors seem convinced that not believing in GW is a bad thing. That leads to some rather tortured reasoning in the latter parts of the paper.
The true believers over at Real Climate have a posting about the now-widely forecast solar minimum (something you’ve been reading about here since the earliest days of the blog in 2009). The posting is informative and balanced until author Gavin Schmidt says,
According to these results, a 21st-century Maunder Minimum would only slightly diminish future warming. Moreover, it would be only a temporary effect since all known grand solar minima have only lasted for a few decades. Critics of this result might argue that the solar forcing in these experiments is only based on the estimated change in total irradiance, which might be an underestimate, or that does not include potential indirect amplifying effects (via an ozone response to UV changes, or galactic cosmic rays affecting clouds). However, our model reproduces the historic Maunder minimum with these estimates of solar irradiance.
Considering that we have, at best, rudimentary observations of solar activity in the 17th Century and no real understanding of why the sun behaves as it does, it seems an extreme act of faith to be touting how well their model (computer simulation) reproduces a Maunder minimum-type event.
His faith in his model leads Gavin to proclaim that the atmosphere will still warm even if a solar event of the Maunder magnitude occurs. Given how bad his (IPCC’s) forecasts have been over the last ten years, it stretches credulity to believe he can make accurate forecasts given major changes in the condition of the sun. This is especially true since his forecasts are already too warm without the sun going completely into a funk. There is more on the topic of the IPCC’s forecasts versus reality here.