Bishop Hill Ridley response to Romm
Dec 22, 2012 Climate: sensitivity This is a guest post by Matt Ridley.
Joe Romm of ThinkProgress described my Wall Street Journal op-ed as:
riddled with basic math and science errors
Yet he fails to find a single basic math or science error in my piece.
He says I :
can’t do simple math
and then fails to produce a single example of my failing to do simple math.
He says I apparently don’t know the difference between water vapor and clouds. He produces no evidence for this absurd claim, which is wrong. Water vapor is a gas; clouds are droplets of liquid water that condense from water vapor. I do know the difference.
He quotes a scientist as saying
it is very clear water vapor…is an amplifying effect. It is a very strong warmer for the climate.
I agree. My piece states:
water vapor itself is a greenhouse gas.
So there is no confusion there. At least not on my part.
However, I do discuss the possibility that clouds, formed from water vapor, either amplify or damp warming – and nobody at this stage knows which. This is the point that my physicist informant was making: the consequence of increased temperatures and water vapor in the atmosphere may be changes in clouds that have a cooling effect. You will find few who disagree with this. As the IPCC AR4 said:
Cloud feedbacks remain the largest source of uncertainty.
Joe Romm disagrees with this consensus, saying
The net radiative feedback due to all cloud types is likely positive.
He gives no backing for this dogmatic conclusion. By contrast, Professor Judith Curry of Georgia Tech says:
The key point is this. The cloud forcing values are derived from climate models; we have already seen that climate models have some fundamental problems in how clouds are treated (e.g. aerosol-cloud interactions, moist thermodynamics). So, climate model derived values of cloud forcing should be taken with a grain of salt. Empirically based determinations of cloud forcing are needed. At AGU, I spoke with a scientist that has completed such a study, with the paper almost ready for submission. Punchline: negative cloud feedback.
Joe Romm quotes Robert Kaufman as saying
I know of no evidence that would suggest that the temperature effect of sulfur emissions are small.
My piece never claimed that aerosols arising from sulfur emissions had a small effect, however as Nic Lewis points out, in the draft AR5 report,
Table 8.7 shows that the best estimate for total aerosol RF (RFari+aci) has fallen from −1.2 W/m² to −0.7 W/m² since AR4, largely due to a reduction in RFaci, the uncertainty band for which has also been hugely reduced. It gives a higher figure, −0.9 W/m², for AFari+aci. However, −0.9 W/m² is not what the observations indicate: it is a composite of observational, GCM-simulation/aerosol model derived, and inverse estimates.”
With regard to the rate of ocean heat absorption, which I wrote was fairly modest, Joe Romm quotes Kevin Trenberth as writing:
On the contrary there is now very good evidence that a lot of heat is going into the deep ocean in unprecedented ways…
and then provides a link to an article citing a study estimating the Earth's current heat absorption as 0.5 W/m². So what "fairly modest" figure does Nic Lewis use? Actually slightly higher: 0.52 W/m²!
Romm then says:
Ridley apparently doesn’t have the first clue what the climate sensitivity means
This is not true. I define sensitivity clearly as the temperature change for a doubling of CO2. I am not talking about the Transient Climate Response, which relates to temperature change only over a 70 year period. There is no confusion at my end.
Romm then says that
Schlesinger notes that an aggressive program of carbon mitigation can limit warming to 2°C and avoid the worst impacts
and that
“It is worth pointing out that there is a healthy debate about Schlesinger’s low estimate”.
So maybe there is some confusion at Romm’s end about what Schlesinger concludes. This is what his paper says (in "Causes of the Global Warming Observed since the 19th Century" in Atmospheric and Climate Science 2012) –
"Additionally, our estimates of climate sensitivity using our SCM and the four instrumental temperature records range from about 1.5°C to 2.0°C. These are on the low end of the estimates in the IPCC’s Fourth Assessment Report. So, while we find that most of the observed warming is due to human emissions of LLGHGs, future warming based on these estimations will grow more slowly compared to that under the IPCC’s “likely” range of climate sensitivity, from 2.0°C to 4.5°C."
Many other recent papers have come to similar conclusions: For example, Schmittner et al. in Science Dec. 11, 2011 URL:
Combining extensive sea and land surface temperature reconstructions from the Last Glacial Maximum with climate model simulations, we estimate a lower median (2.3 K) and reduced uncertainty (1.7 to 2.6 K as the 66% probability range, which can be widened using alternate assumptions or data subsets). Assuming that paleoclimatic constraints apply to the future, as predicted by our model, these results imply a lower probability of imminent extreme climatic change than previously thought.
Meanwhile for transient climate response, similar low estimates are also now being made. See for example Gillett et al.'s 2012 article "Improved constraints on 21st-century warming derived using 160 years of temperature observations" in Geophysical Research Letters:
Our analysis also leads to a relatively low and tightly-constrained estimate of Transient Climate Response of 1.3–1.8°C, and relatively low projections of 21st-century warming under the Representative Concentration Pathways.
Or Padilla et al.'s 2011 article "Probabilistic estimated of transient climate sensitivity subject to uncertainty in forcing and natural variability" in the Bulletin of the American Meteorological Association at URL::
For uncertainty assumptions best supported by global surface temperature data up to the present time, this paper finds a most likely present-day estimate of the transient climate sensitivity to be 1.6 K, with 90% confidence the response will fall between 1.3 and 2.6 K, and it is estimated that this interval may be 45% smaller by the year 2030. The authors calculate that emissions levels equivalent to forcing of less than 475 ppmv CO2 concentration are needed to ensure that the transient temperature response will not exceed 2 K with 95% confidence.
Mr Romm seems confused about methane outgassing feedbacks, arguing that even if climate sensitivity is low, these may dominate. Suffice to say that in this he has drifted a long way from the consensus.
Mr Romm seems determined to rule out even the possibility of low climate sensitivity in the teeth of strong evidence. I can see why he wishes to do so, his job depending on there being a dangerous future. I do not understand where he gets his certainty.
Finally, Mr Romm throws the term “anti-science” at me, again with no evidence. I cited peer reviewed papers and made the scientific argument that the latest data be considered in estimating sensitivity. That is pro science. What is anti-science is to make false accusations and try to shut down legitimate debate. Hard working people all over the world are now risking their lives as well as their wallets for the consequences of current climate policy (see Indur Goklany’s paper “Could biofuel policies increase death and disease in developing countries?”). They have a right to ask that those who determine the science behind such policies are open-minded. On the evidence of MrRomm’s astonishing outburst, my doubts about this are growing.
Reader Comments (110)
jferguson
Why no, of course not. Why Richard would no more write an A4 screed of totally off topic material than he would forget to join the other 70 odd people wishing the Bish and everyone else a Merry Christmas.
Ding Dung merrily on high. And you still want me banned, I take it.
get on topic Drake, or be assumed to be another ad hom troll...binary choice
Oh, my ... Richard D. is at it again. Riding his hobby-horse into yet another thread, and reframing and attributing to others that which they have not said.
Richard D's context-free reframing:
Dung's actual words:
This makes it quite obvious that Richard D. seems to have very conveniently overlooked the fact that all Dung (amongst others) has ever asked is that Richard D. restrict his hobby-horse riding to the discussion threads dedicated to such a topic.
And I'm still not sure who decided that Richard's Rules of Order™ should be the prevailing ethos of this otherwise harmonious congregation.
Why's everyone started picking in Richard? Seems unfair to me.
Regarding use of "assumed names", I don't see any problem with folk who have through habit used the same alias since the days when full names weren't possible on the internet. I've used steveta for nearly 20 years, and since my name is in fact Steve Taylor, I don't see this as hiding anything.
My objection, and I suspect Richard's too, is to people who habitually change their aliases to try and evade the fact that their nonsense arguments, usually about a failed understanding of A-level thermodynamics, have been repeatedly debunked by some real scientists, but to no avail.
For those such as Martin A who would like to continue this as a reasoned discussion on another thread, I suggest you browse the "Discussion" threads on BH, where you will find numerous previous attempts to explain the GHE by some pretty knowledgeable folk, where you will find the usual suspects remaining obstinately unconvinced.
For the first time since my tentative post of 9th November, someone has represented my views exactly right. Thanks steveta. That was exactly my focus on this thread, which Dung deliberately broadened to evade the specific points I was making.
No hard feelings, Hilary, but since 9th November Dung and a few allies (not limited to diogenes) have misrepresented my views so completely that the suggestion that I should be banned is not the least unexpected. These guys don't play fair. Are you lending your support? A very misguided way, in my view, for you to use your influence.
Dung is the one who re-framed my concerns on this thread. My concern here was wholly to do with whether "failed understanding of A-level thermodynamics," as steveta puts it, should be expressed and debated, yet again, on a thread about much more important matters triggered by Matt Ridley's Wall Street Journal article of 18th December.
A polemicist lies in the eye of the beholder; and it takes a polemicist to call someone else a polemicist. One thing is certain and that is the rules of the game, The Scientific Method. Remove all internal biases, remove all logical fallacies, remove all "consensus" claiming vetting by straw poll voting by persons / groups with major skin in the game, measure science by scientific standards - hypothesis, data, validation, reboot the hypothesis. Simple as that. This is not relativistic Kuhnian science wherein if you repeat something enough times, or if repeated by enough people it becomes a new scientific paradigm or scientific fact. Models cannot be used to validate science. Models cannot be used to project decadees or centuries out of period. It is nonsense.
Richard - I don't think you realise how you are coming across :( talk of allies, etc, etc.., which is divisive talk, with you trying to polarise and label people into suporters of you or not and making it tribal. which IS troll like behaviour
As to Romm, I wonder how much influence he still has, he is so far too the extreme, he organised his followers to send Richard Black BBC abusive emails, because Richard was not alarmist enough about the Arctic to Romms taste (by publishing his email address)
and Richard Black did confirm he got some abuse from it
(though not as much as he gets from sceptics :( )
No more discussion of aliases.
No more personal remarks.
Thanks.
Barry: only just seen this and of course the Bish. I agree that none of us knows exactly how we come across. I think 'allies' was OK but I note the way you read it, thanks.