This is me, tiptoeing towards the spotters guide to bloggers I promised. But I’ve been distracted, because I was pointed at Climate scientist: “Positive carbon-climate feedback is still very likely” — and even without “a runaway feedback,” warming will be “substantial and critical” Plus a review of recent research on amplifying feedbacks at ClimateProgress. I think most of it is by Brad Johnston, but there is an addendum by Romm. So, what is wrong with it?
First off, you have to wade through too much foam to get to the substance, which puts me in a bad mood. Once you know the structure of the post you blip over the goo and dribble, but for anyone coming to it fresh there is just too much “set you up in the right frame of mood to accept the framing” type stuff.
What BJ is doing is attacking some stuff in FirstPost by Tim Edwards (who he?) ‘Runaway climate change’ ‘unrealistic’, say scientists. I don’t know why. Runaway climate change *is* unrealistic (or at the very least, improbable. Certainly, I’m not worrying about it). The report isn’t wonderful, but for example it says:
Today, Sir Muir Russell’s independent review of the Climategate scandal, in which hackers stole and circulated emails from the Climatic Research Unit at the University of East Anglia, cleared climate scientists of malpractice. It is the third inquiry to do so – leading to calls of ‘whitewash’ from climate change sceptics.
I wouldn’t have put in the whitewash bits, but never mind. Or:
The Netherlands Environmental Assessment Agency (PBL) said the Intergovernmental Panel on Climate Change’s 2007 report contained “no errors that would undermine the main conclusions” … Embarrassingly for PBL, it had to admit it was the source of one of the most glaring errors – a claim that 55 per cent of the Netherlands was at risk of flooding because it lies under sea level.
Quite good, really. But the CP article rather misleadingly focuses on one line from the report:
“Climate change skeptics might say the new study is yet another nail in the coffin of the IPCC report,” Edwards writes
Now this is unfair. That line comes towards the end of the FirstPost piece, and a fuller quote is:
Climate change sceptics might say the new study is yet another nail in the coffin of the IPCC report, which says: “Anthropogenic warming could lead to some effects that are abrupt or irreversible, depending upon the rate and magnitude of the climate change.”
But mainstream scientists will just be pleased that Fluxnet has given them real-world measurements upon which to base their computer models – which could be another nail in the coffin of climate change scepticism, relying as it so often does on quibbles over the quality of data.
So while giving semi-equal weighting to the “skeptics” isn’t great, it is balanced by the sane view, which indeed is the end-of-article view.
BJ goes on the claim that “Edwards utterly misrepresented the research” and indulges in “fevered speculation”. Neither of these claims are reasonable.
I think that is enough knocking BJ. I’ll now try and talk about the actual issue involved, which is carbon cycle feedbacks.
The idea is that as the world warms, certain processes that “regulate” the atmospheric carbon diooxide get out of whack. For example, warmer oceans will absorb less CO2. Or less precipitation could lead to drying in the Amazon and dieback of the forest there, releasing CO2. And increasing soil temperatures could lead to increased life in the soils, again leading to more CO2 being produced. And more Co2 leads to more warming which feeds back into the cycle. In this case, This Week reports:
Using Fluxnet, a global network of more than 250 ‘flux towers’ to sample CO2 concentrations, a team of researchers from the Max Planck Institute has found that, actually, temperature has a much smaller effect on CO2 release than previous studies claimed. The researchers, led by Miguel Mahecha, found that the rate at which plants and microorganisms produce CO2 in ecosystems from tropical rainforests to savannah does not even double when the temperature increases by 10°C from one week to the next.
As it happens, I’ve no idea if that is a true paraphrase of the paper, but it sounds entirely plausible. The point is that just because you have *feedback* doesn’t mean you have *runaway feedback*. This study isn’t the last word on the subject, of course, but it does tell you something useful about how soils respond to temperature.
Where FirstPost errs is in writing ‘Runaway climate change’ ‘unrealistic’, say scientists as though it was news. It isn’t; its a commonplace. But it is a mistake that many people make. Where BJ errs is in attacking a fairly harmless piece for no obvious reason, unless it was to fill up column inches. This is all assuming that ThisWeek is just some-or-another website. If it has claims to be “on the side of the angels” then I might hold it to higher standards. But BJ’s piece wouldn’t get any better.