[UPDATE]Real Climate did not like the figure shown below, so I responded to them with the following request, submitted as a comment on their site:
I’d be happy to work from a proposed adjustment directly from you, rather than rely on the one proposed by Steve McIntyre or the one you point to from The Independent.
Thompson et al. write: “The new adjustments are likely to have a substantial impact on the historical record of global-mean surface temperatures through the middle part of the twentieth century.”
It is hard to see how temperatures around 1950 can change “substantially” with no effect on trends since 1950, but maybe you have a different view. Lets hear it. Give me some better numbers and I’ll use them.
Their response was to dodge the request:
Response: Nick Rayner, Liz Kent, Phil Jones etc. are perfectly capable of working it out and I’d suggest deferring to their experience in these matters. Whatever they come up with will be a considered and reasonable approach that will include the buoy and drifter issues as well as the post WW-II canvas bucket transition. Second guessing how that will work out in the absence of any actual knowledge would be foolish. – gavin
But doesn’t speculation that no changes will be needed to the IPCC trend estimates count as “second guessing,” or pointing to a graph in The Independent as likely being correct?
Similarly, in the comments below climate scientist James Annan criticized the graph in this post and when asked to provide an alternative adjustment, he declined to do so.
If these guys know what is “wrong” then they must have an idea about what is “right”.
Real Climate writes an entire post responding to Steve McIntyre’s recent discussions of buckets and sea surface temperatures, explaining why the issue doesn’t really matter, but for some weird reason they can’t seem to mention him by name or provide a link to what they are in fact responding to. (If the corrections don’t matter, then one wonders, why do them? Thompson et al. seemed to think that the issue matters.)
Real Climate does seem have mastered a passive voice writing style, however. Since they did have the courtesy to link here, before calling me “uninformed” (in deniable passive voice of course), I though a short response was in order.
Real Climate did not like our use of a proposed correction suggested by He Who Will Not Be Named. So Real Climate proposed another correction based on a graphic printed in The Independent. Never mind that the correction doesn’t seem to jibe with that proposed by Thompson et al., but no matter, we used the one suggested by Mr. Not-To-Be-Named so lets use Real Climate’s as well and see what difference it makes to temperature trends since 1950. Based on what Real Climate asserts (but oddly does not show with numbers), you’d think that their proposed adjustment results in absolutely no change to mid-20th century trends, and indeed anyone suggesting otherwise is an idiot or of ill-will. We’ll lets see what the numbers show.
The graph below shows a first guess at the effects of the Real Climate adjustments (based on a decreasing adjustment from 1950-60) based on the graphic in The Independent.
What difference to trends since 1950 does it make? Instead of the about 50% reduction in the 1950-2007 trend from the first rough guess from you-know-who, Real Climate’s first guess results in a reduction of the trend by about 30%. A 30% reduction in the IPCC’s estimate in temperature trends since 1950 would be just as important as a 50% reduction, and questions of its significance would seem appropriate to ask. But perhaps a 30% reduction in the trend would be viewed as being “consistent with” the original trend
Try again Real Climate. And next time, his name is STEVE MCINTYRE — and his blog is called CLIMATE AUDIT. There is a lot of science and civil discussion there, with a healthy mix of assorted experts and a range of ordinary folks. Questioning scientific conclusions is a lot healthier for science than rote defense, but we all learned that in grad school, didn’t we?