It’s again time for one of those puzzling results that if they turn out to be true, would have some very important implications and upset a lot of relatively established science. The big issue of course is the “if”. The case in question relates to some results published this week in Nature by Joanna Haigh and colleagues. They took some ‘hot off the presses’ satellite data from the SORCE mission (which has been in operation since 2003) and ran it through a relatively complex chemistry/radiation model. These data are measurements of how the solar output varies as a function of wavelength from an instrument called “SIM” (the Spectral Irradiance Monitor).
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IPCC report card
Update: Nature has just published a thoughtful commentary on the report
The Inter-Academy Council report on the processes and governance of the IPCC is now available. It appears mostly sensible and has a lot of useful things to say about improving IPCC processes – from suggesting a new Executive to be able to speak for IPCC in-between reports, a new communications strategy, better consistency among working groups and ideas for how to reduce the burden on lead authors in responding to rapidly increasing review comments.
As the report itself notes, the process leading to each of the previous IPCC reports has been informed from issues that arose in previous assessments, and that will obviously also be true for the upcoming fifth Assessment report (AR5). The suggestions made here will mostly strengthen the credibility of the next IPCC, particularly working groups 2 and 3, though whether it will make the conclusions less contentious is unclear. Judging from the contrarian spin some are putting on this report, the answer is likely to be no.
Information levels
Rasmus’ recent post on the greenhouse effect raised some interesting points concerning the technical level at which posts or other public communications should be written. This was a relatively technical article as these things go, eschewing the very basic ‘the greenhouse effect is like a blanket’ but not really approaching the level of a technical paper on the subject (no line-by-line calculations for instance). Nonetheless, there were complaints that was too much to be absorbed by the lay public, counter-arguments that making it too simple was patronising, as well as complaints that the discussions were not technical enough (for instance in explaining stratospheric cooling). In these discussions there are clearly the outlines of a common debate, and perhaps a way forward in the future.
The uncertainty prayer
Seen at a meeting yesterday:
Grant us…
The ability to reduce the uncertainties we can;
The willingness to work with the uncertainties we cannot;
And the scientific knowledge to know the difference.
(Drawn from a white paper on the use of climate models for water managers).
Discuss.
What do climate scientists think?
) Leakegate: A retraction
Back in February, we commented on the fact-free IPCC-related media frenzy in the UK which involved plentiful confusion, the making up of quotes and misrepresenting the facts. Well, a number of people have pursued the newspapers concerned and Simon Lewis at least filed a complaint (pdf) with the relevant press oversight body. In response, the Sunday Times (UK) has today retracted a story by Jonathan Leake on a supposed ‘Amazongate’ and published the following apology:
The article “UN climate panel shamed by bogus rainforest claim” (News, Jan 31) stated that the 2007 Intergovernmental Panel on Climate Change (IPCC) report had included an “unsubstantiated claim” that up to 40% of the Amazon rainforest could be sensitive to future changes in rainfall. The IPCC had referenced the claim to a report prepared for the World Wildlife Fund (WWF) by Andrew Rowell and Peter Moore, whom the article described as “green campaigners” with “little scientific expertise.” The article also stated that the authors’ research had been based on a scientific paper that dealt with the impact of human activity rather than climate change.
In fact, the IPCC’s Amazon statement is supported by peer-reviewed scientific evidence. In the case of the WWF report, the figure had, in error, not been referenced, but was based on research by the respected Amazon Environmental Research Institute (IPAM) which did relate to the impact of climate change. We also understand and accept that Mr Rowell is an experienced environmental journalist and that Dr Moore is an expert in forest management, and apologise for any suggestion to the contrary.
The article also quoted criticism of the IPCC’s use of the WWF report by Dr Simon Lewis, a Royal Society research fellow at the University of Leeds and leading specialist in tropical forest ecology. We accept that, in his quoted remarks, Dr Lewis was making the general point that both the IPCC and WWF should have cited the appropriate peer-reviewed scientific research literature. As he made clear to us at the time, including by sending us some of the research literature, Dr Lewis does not dispute the scientific basis for both the IPCC and the WWF reports’ statements on the potential vulnerability of the Amazon rainforest to droughts caused by climate change.
In addition, the article stated that Dr Lewis’ concern at the IPCC’s use of reports by environmental campaign groups related to the prospect of those reports being biased in their conclusions. We accept that Dr Lewis holds no such view – rather, he was concerned that the use of non-peer-reviewed sources risks creating the perception of bias and unnecessary controversy, which is unhelpful in advancing the public’s understanding of the science of climate change. A version of our article that had been checked with Dr Lewis underwent significant late editing and so did not give a fair or accurate account of his views on these points. We apologise for this.
Note that the Sunday Times has removed the original article from their website (though a copy is available here), and the retraction does not appear to have ever been posted online. Here is a scan of the print version just in case there is any doubt about its existence. (Update: the retraction has now appeared).
This follows on the heels of a German paper, the Frankfurter Rundschau, recently retracting a story on the ‘Africagate’ non-scandal, based on reporting from….. Jonathan Leake.
It is an open question as to what impact these retractions and apologies have, but just as with technical comments on nonsense articles appearing a year after the damage was done, setting the record straight is a important for those people who will be looking at this at a later date, and gives some hope that the media can be held (a little) accountable for what they publish.
Climate Change Commitment II
) A couple of months ago, we discussed a short paper by Matthews and Weaver on the ‘climate change commitment’ – how much change are we going to see purely because of previous emissions. In my write up, I contrasted the results in M&W (assuming zero CO2 emissions from now on) with a constant concentration scenario (roughly equivalent to an immediate cut of 70% in CO2 emissions), however, as a few people pointed out in the comments, this exclusive focus on CO2 is a little artificial.
On attribution
How do we know what caused climate to change – or even if anything did?
This is a central question with respect to recent temperature trends, but of course it is much more general and applies to a whole range of climate changes over all time scales. Judging from comments we receive here and discussions elsewhere on the web, there is a fair amount of confusion about how this process works and what can (and cannot) be said with confidence. For instance, many people appear to (incorrectly) think that attribution is just based on a naive correlation of the global mean temperature, or that it is impossible to do unless a change is ‘unprecedented’ or that the answers are based on our lack of imagination about other causes.
In fact the process is more sophisticated than these misconceptions imply and I’ll go over the main issues below. But the executive summary is this:
- You can’t do attribution based only on statistics
- Attribution has nothing to do with something being “unprecedented”
- You always need a model of some sort
- The more distinct the fingerprint of a particular cause is, the easier it is to detect
Note that it helps enormously to think about attribution in contexts that don’t have anything to do with anthropogenic causes. For some reason that allows people to think a little bit more clearly about the problem.
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Ocean heat content increases update
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) There is a new paper in Nature this week on recent trends in ocean heat content from a large group of oceanographers led by John Lyman at PMEL. Their target is the uncertainty surrounding the various efforts to create a homogenised ocean heat content data set that deals appropriately with the various instrument changes and coverage biases that have plagued previous attempts.
We have discussed this issue a number of times because of its importance in diagnosing the long term radiative imbalance of the atmosphere. Basically, if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere – and that somewhere is mainly the ocean. (Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).
Second CRU inquiry reports
The Oxburgh report on the science done at the CRU has now been published and….. as in the first inquiry, they find no scientific misconduct, no impropriety and no tailoring of the results to a preconceived agenda, though they do suggest more statisticians should have been involved. They have also some choice words to describe the critics.
Carry on…