tag:blogger.com,1999:blog-8993615971333537173.post8212170274004473408..comments2021-06-18T13:42:54.535+01:00Comments on plumbum: Fears of Climate ChangePaulBhttp://www.blogger.com/profile/16861432701458977844noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-8993615971333537173.post-13171458019790654902012-12-21T22:30:32.870+00:002012-12-21T22:30:32.870+00:00I'm re-reading Gregory after a long time. I th...I'm re-reading Gregory after a long time. I think "he got a median sensitivity of 6.1K, with a confidence interval stretching down to negative numbers and up to infinity - the method was interesting, but the results were useless" is a mis-paraphrase of "The 90% confidence interval for ΔT2× extends up to infinity, and beyond to negative values". We've already had "From the probability distribution of ΔT2× we obtain a 90% confidence interval, whose lower bound (the 5th percentile) is 1.6 K". So your implication that the confidence interval, "centered" on 6.1, stretches down to negative and up to infinity, is wrong. Its bounded below, but wraps round inifnity (unphysically) above. At least that's my reading. Which means it isn't useless, because it provides a lower bound (but not an upper).<br /><br />That reading is supported by "We consider that the lower bound is an important constraint on climate sensitivity, because it is objectively derived, and independent of GCM results for ΔT2×."<br /><br />Note also that the result isn't purely observational (as I think Lewis and his ilk have tried to suggest). It only doesn't need model estimates for ΔT2×.William M. Connolleyhttps://www.blogger.com/profile/05836299130680534926noreply@blogger.com