Tuesday, May 21, 2013

More denier weirdness - Anthony Watts praises a paper as a sea change, but sneers at the author's findings

Sou | 2:17 AM Go to the first of 11 comments. Add a comment

How Watts Praises a Paper

Watts writes a headline about a new paper (discussed here):

Why the new Otto et al climate sensitivity paper is important – it’s a sea change for some IPCC authors

How Watts decides what the paper means

With the modest rate of warming stated by Otto et al, the impacts of global warming are more likely to be positive than negative for humanity in the foreseeable future; increased crop yields for example.
Oh yeah? Pull the other one...(and the old "CO2 is plant food, praise the lord"? Sheesh!)

How Watts tells his readers to ignore the authors of the paper he praises

Watts tells his readers to ignore those silly old authors. "Oh, Sure" he sneers!
Anthony snorts: The BBC says they had it all covered before and this new paper is “consistent” with previous works. Oh, sure.
Quoting the BBC:…when it comes to the longer term picture, the authors say their work is consistent with previous estimates. The IPCC said that climate sensitivity was in the range of 2.0-4.5C.
This latest research, including the decade of stalled temperature rises, produces a range of 0.9-5.0C.
“It is a bigger range of uncertainty,” said Dr Otto.
“But it still includes the old range. We would all like climate sensitivity to be lower but it isn’t.”

How Watts looks like a fool (again)

The lead author, Dr Otto responds to a question from the BBC:
Is there any succour in these findings for climate sceptics who say the slowdown over the past 14 years means the global warming is not real?
"None. No comfort whatsoever," he said.

Anthony Watts thumbs his nose at the authors and decides to take comfort anyway: "Meanwhile, in lower sensitivity land, “the pause” in global temperatures continues, and is approaching the Santer definition...If “the pause” reaches 17 years, what then?":


  1. I'd be a bit more cautious if I were you. James Annan knows what he is talking about. See http://julesandjames.blogspot.co.uk/2013/05/more-on-that-recent-sensitivity-paper.html

    1. Maybe so, William. James might have a point about the politics, but then he tends to the low side with his own Bayesian workings.

      It doesn't change the fact that Anthony spruiks a paper but then dismisses outright what the authors themselves say about it. Nor that he is silly enough to keep touting "CO2 is plant food, Alleluia"

      For my own personal take on the paper, see my previous article. I don't dismiss it out of hand, but I'm also cautious about for three reasons. (Cheeky of me perhaps, as I'm no expert.)

      1. The estimates change too much between such short periods plus too much weight on 2000-09. This suggests that something is amiss - maybe ocean heat content as Sherwood suggests.

      2. It doesn't seem to be consistent with what paleo data indicates.

      3. The low in both TCR and ECS of 0.9 C seems ridiculously low. (Yes, I know it's just at the edge of the prob estimates, but all the same.)

      BTW I'm tickled pink that you've dropped in here :) Thanks for the plug the other day, too.

    2. "James Annan knows what he is talking about."

      Well, recently he gave his best personal estimate of 2.0-4.0K with a most likely value at 2.5K. So all his personal grudges aside, I assume on a consistent day he would say that Otto et. al is biased low quite a bit?


    3. JohnL - I took William to be talking about the fact that the authors put two bob each way by quoting their wide ranges when talking to the press, rather than focusing on their 'best estimates'. James doesn't indicate one way or another what he thinks of their 'best estimate', except he seems to like it being on the low side with all the Bayesian analyses.

      Neither James nor William say that the paper was shonky or 'biased'.

      I'm talking more about the results themselves than the politics of it all.

      There'll probably be some fun and games behind the scenes when AR5 gets finalised. Would be ironic if it came out with a lowered climate sensitivity and a year or two later we got a massive El Nino that blew it out of the water.

    4. (I'm not unaware of the double entendre re El Nino.)

    5. To say the work is biased doesn't mean it is "bad" or authors having some biased intention, it is just due to the methods used. Apparently that is what we have for Otto et al if we compare with all the other knowledge in the area.

      "Would be ironic if it came out with a lowered climate sensitivity and a year or two later we got a massive El Nino that blew it out of the water."

      On the more humorous side, that is actually a scary thought. All the IPCC-authors suddenly becoming naive Bayesians: Each El Nino the estimates of sensitivity turns high, each La Nina it gets very low. There are no conceptual meta analysis anymore just putting numbers from new "observations" into their Bayesian formula...

    6. Okay, I get what you are saying John.

      Scientists are wanting more and better recording but it costs money (supporting the case for more international collaboration). If they could get more complete measurements of TOA incoming/outgoing radiation and better measures of ocean heat content then that should tighten things up and allow improved observation-based estimates rather than estimates based on incomplete (recent) priors. But it will take time to build up a more complete longitudinal record, even if/when the instrumentation improves.

  2. Here is another article on the paper that may be of interest.

  3. Greg Laden's latest post injects a dose of reality - the effects of climate change are obvious here and now, regardless of the ongoing debate about climate sensitivity:


    1. Greg Laden's article is excellent. Meaning I couldn't agree more :)

      It's also very thorough - whether or not you agree (and who wouldn't?), it's a thought-provoking article and well worth a read.

  4. Alexander Otto article just up on Met Office research news page.

    Otto writes (emphasis added):

    Our study implies a 5-95% confidence interval for the transient climate response of 0.9-2°C compared to the range of 1-2.5°C represented by the CMIP5 models. Acknowledging these uncertainties makes the differences look a bit less game-changing: results from the most recent decade appear to exclude the top 1/3rd of the CMIP5 range, but the TCR range estimated from the 1970-2009 period as a whole (0.7-2.5°C) does not, and we should always be careful not to over-interpret a single decade. The CMIP5 multi-model mean of 1.8°C is well within our confidence interval, and only models with very high TCR values look potentially inconsistent with the most recent data, a conclusion consistent with e.g. Stott et al. (2013).

    What are the implications of a TCR of 1.3°C rather than 1.8°C? The most likely changes predicted by the IPCC's models between now and 2050 might take until 2065 instead (assuming future warming rates simply scale with TCR). To put this result in perspective, internal climate variability and uncertainties in future forcing could well have more impact on the global temperature trajectory on this timescale.


    This study highlights the importance of continued careful monitoring of the climate system, and also the dangers of over-interpreting any single decade's worth of data.


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