Bishop Hill IPCC hides the good news
Mar 6, 2014 Climate: sensitivity From GWPF:
A new report published by the Global Warming Policy Foundation shows that the best observational evidence indicates our climate is considerably less sensitive to greenhouse gases than climate models are estimating.
The clues for this and the relevant scientific papers are all referred to in the recently published Fifth Assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). However, this important conclusion was not drawn in the full IPCC report – it is only mentioned as a possibility – and is ignored in the IPCC's Summary for Policymakers (SPM).
For over thirty years climate scientists have presented a range for climate sensitivity (ECS) that has hardly changed. It was 1.5-4.5°C in 1979 and this range is still the same today in AR5. The new report suggests that the inclusion of recent evidence, reflected in AR5, justifies a lower observationally-based temperature range of 1.25–3.0°C, with a best estimate of 1.75°C, for a doubling of CO2. By contrast, the climate models used for projections in AR5 indicate a range of 2-4.5°C, with an average of 3.2°C.
This is one of the key findings of the new report Oversensitive: how the IPCC hid the good news on global warming, written by independent UK climate scientist Nic Lewis and Dutch science writer Marcel Crok. Lewis and Crok were both expert reviewers of the IPCC report, and Lewis was an author of two relevant papers cited in it.
In recent years it has become possible to make good empirical estimates of climate sensitivity from observational data such as temperature and ocean heat records. These estimates, published in leading scientific journals, point to climate sensitivity per doubling of CO2 most likely being under 2°C for long-term warming, with a best estimate of only 1.3-1.4°C for warming over a seventy year period.
“The observational evidence strongly suggest that climate models display too much sensitivity to carbon dioxide concentrations and in almost all cases exaggerate the likely path of global warming,” says Nic Lewis.
These lower, observationally-based estimates for both long-term climate sensitivity and the seventy-year response suggest that considerably less global warming and sea level rise is to be expected in the 21st century than most climate model projections currently imply.
“We estimate that on the IPCC’s second highest emissions scenario warming would still be around the international target of 2°C in 2081-2100,” Lewis says.
The full report is here.
Bishop Hill
Piers Forster has penned a response at Ed Hawkins' Climate Lab Book site.
Reader Comments (155)
The production and elevation of '2C' as a critical limit is another of the tawdry devices of climate alarm campaigners. I recall, off the top of my head, that there is annual variation in global mean surface temperature of between 3 and 4C, due to our elliptical orbit around the sun which has us nearer to it during the northern hemisphere winter, and furthest away during our summer. In other words, an annual perturbation of nearly twice the magic '2C' is business-as-usual.
Steve: You think it's wise for TBYJ to exit this thread, just because someone challenged him? And you are indicating that you are doing the same, just because you don't like my answer, which provides numerous links supporting my point of view? What a robust attitude to evidence-based discussion. This is what makes the global warming debate so great!
But I also acknowledge that the biofuel subsidy issue is not the subject of Lewis & Crok. I won't say more on that now.
John Shade
You are out by a factor of ten. The actual seasonal variation is closer to 0.3C than 3C.
http://www.woodfortrees.org/plot/hadcrut3gl/from:2003/to:2013/every
Given that temperature is an intensive variable and nobody can say what the earth's average temperature means or how to define it or measure it, talk of an arbitrary 2C temperature rise is just BS.
Phillip: I have sympathy, as an early reader of Essex and McKitrick. As Richard Lindzen said to me when I asked him about blog critics of climate sensitivity the other day one thing it certainly doesn't have anything useful to say about are the rapid changes in climate in the past that were triggered by local phenomena, such as the cycles brilliantly explained by Milankovitch. At least I think that was his drift. He's the expert, I'm not.
Thanks for caring, Entropic (3:43 PM), but your correction is not a correct one. I guess you may be getting confused between anomalies and actual temperatures.
During the 20th century, the global mean temperature for January was 12C, and for July it was 15.8C according to NOAA. I'll leave it as an exercise for you to find out why the mean temperature is lower when we are nearest the sun than when we are furthest away.
Where exactly are the tragic effects of 2C likely to be seen. I think we've established it is not in Oxfordshire. Not in Canada either. The tropics? I think they aren't expecting two degrees because of negative feedback, which happens every day already. The poles? Sea level rise? Anything else?
If it is SO important that we limit it to 2 degrees, what happens at 2.1? What disaster which we could be adapt to in forty or fifty years?
I suppose I'd like to read the best catastrophe paper. Any refs? Otherwise I suspect this really is a figure picked from the air, the likely reason for plumping for two being that by CAGW predictions we are committed to that anyway.
How nice if that Monty chap was to eschew the name-calling and stick to whatever science he is relying on. Not convinced by any approach which uses paleo to establish CS.
(And I have often asked for the justification for the concept of CS. I can see it as a bit of obviousology but I wonder whether the real world works like that. )
To some of the posts above. RCP 8.5 is NOT business as usual. It is a highly unlikely extreme. Business as usual equivalent to SRES A1B (or it's brethren) is somewhere between RCP4.5 and RCP 6.0, and closer to RCP4.5. Go read the descriptions published by the IPCC. Claiming RCP8.5 is the 'real' reference unfairly moves the goalposts again.
Rud
From the report:
I'm not sure I understand why the difference between emissions and concentrations.
Richard Drake: Am I the anonymous sceptic saying something stupid you referred to?
geronmo: with that nifty typo it's hard to say!
Bad Andrew
This is what "extreme weather increasing" means.
http://robertscribbler.wordpress.com/2014/03/05/sea-ice-loss-human-warming-places-earth-under-ongoing-fire-of-severe-weather-events-through-early-2014-likelihood-of-extremes-for-some-regions-increases-by-500/
Entropic man
Could you re-submit your list to only include those items which have gone beyond anything in the current inter-glacial. These are the ones I personally will worry about. In the past when researching claims like your list I find that most things are in fact not unusual. Glaciers and Tree lines being two that stick in my mind.
a single glacier example
a single treeline example
Using the principle that a single error negates your items then those two fall, I'm not wasting time on the rest. It's really up to you to prove them as unique.
Many Thanks
Sandy.
Richard Betts
I think you betray your belief system when you say 'How strong is the human influence'. As a scientist I would expect you to phrase this in more neutral terms, such as, 'the effect, if any, of human influence'. Whilst I am a great admirer of radiative physics I am by no means convinced that it rules the climate in the way the consensus scientists believe. It is quite possible that man's influence on the climate, or to get back on track, the influence of man's emissions of CO2 on the climate, will not be heard above the noise.
Monty
"climate scientists like me and Richard Betts"
Careful with the snugness there, Oh Exhalted One. Of all the sciences that my (uniformly v. smart) children and grandchildren have chosen to study and work within, the oxymoronic "climate scence" featured vanishingly far down the list of choices.
I given you Lindzen @ the House of Commons for why.
So steady on with the patronising attitude in this place if you please, Sir Montague. You may wish to reconsider and in future to dial that back just a little.
Richard Drake, The typo isn't mine, So if you wouldn't mind answering the question I'd appreciate it. And if it is me I'd also appreciate which part of what I wrote you thought stupid. One can always learn from one's betters.
SandyS,
> Could you re-submit your list to only include those items
which have gone beyond anything in the current inter-
glacial. These are the ones I personally will worry about.
That is a bit like saying, "this house burnt nearly to the ground in the 17th century. I'll worry about the fire in the roof when it gets worse than it was then".
Bishop Hill
I'm a bit confused about that statement too. The second part is correct - CO2 emissions have indeed been at or above RCP8.5, see here (Slide 20) (Rud Istvan, please note!)
However I don't know where the first part statement comes from, because for the first 10-15 years or so of the RCP scenarios (starting at 2005) the CO2 concentrations of the different scenarios are virtually indistinguishable from one another - see here (inset - you may need to zoom in). This is because CO2 concentrations in any particular year are affected by the total of previous emissions (most of which are still in the atmosphere) more than the emissions in that year. Therefore if the observed concentrations are close to any of the scenarios in recent years, then they will be close to all scenarios.
It does seem to be an odd thing to say.
Headless Chicken
No, this is entirely the point. The existence of some degree of human influence on climate is accepted widely enough not to have to make that caveat - this acceptance includes the GWPF, as well as our host here, and most if not all other prominent sceptics such as Christopher Monckton. The question is not whether it exists, but how strong it is.
Those above who said that the debate has always been in this area - see Headless Chicken's comment, and also recall posts by Doug Keenan on the statistical significance of observed warming. I seriously think we can, and should, move on from those now.
Sandy S
Tiny CO2 did ask!
Best discussed over on the discussion thread. I will say that a number of the items on my list are trends. Most haven't gone above the Holocene optimum level yet. The average global temperatures have reached that level, but the rest won't catch up until there has been time for the system to come to equilibrium.
SandyS
Most of the list is not worth worrying about. They are measures of change but not civilization killers. Some, like higher tree lines are good news for the local farmers , though I'm not sure how keen Alaska and Canada would be to lose the permafrost and the ice roads.
The potential killers are sea level and the shifts in rainfall patterns. For example, what happens to your agriculture when your annual rainfall starts to fall mostly on the country next door? Do you let your people starve, negotiate for access to their farmland or invade them?
Entropic man
Did you post a link for your temperature claim? Sorry if you did my brief search couldn't find it. It's a bit like getting hold of a bar of soap in a bath with all the threads on similar topics.
I'm still not convinced or panicking. My view is that the combined effect of of Back radiation (or whatever you want to call it) and the increased mass of the atmosphere from the increased %age of CO2 will be minuscule.
(There are a couple of threads on Venus over at Steve Goddard's blog should you feel inclined to have a look, there's a link in the sidebar here)
Sandy
RB: " It has moved into the area where it really needs to be – exactly how strong is the human influence, how much change can we expect in the future, and what sort of impacts/risks does this imply?"
This pretty much repeats what Ed Hawkins said and I don't quite understand it. It looks as though you think you've "won" and are planning to be magnanimous in victory by allowing the vanquished some say in how bad the human influence has been, how bad the future changes are going to be and how bad the concomitant disasters will be. That can't be it surely? but I'm having difficulty understanding what it is exactly that you think's happened with the publication of this report. I'm at a complete loss. Is it that you believe they've conceded an ECS somewhere near 3C and that gives scope for a negotiated agreement?
Richard - you may not have seen it but I asked you here:
http://bishophill.squarespace.com/blog/2014/3/6/ipcc-hides-the-good-news.html?currentPage=2#comment20803686
...with a list of 5 scientists who present careful, thoughtful work in the peer reviewed literature that the deterministic model of climate is flawed. Until you show this body of work to be wrong, how can you possibly argue that this line of debate should come to an end?
Entropic Man
"At present TCR is probably around half ECS for the CO2 added so far"
Statement made - based upon what evidence?
"there is no sign that we are getting any closer to equilibrium."
Statement made - based upon what evidence? Is things not changing not a sign of "equilibrium"?
"TCR will increase, but remain a long way below ECS until CO2 concentrations stabilise" - this I believe is theory, already proven to be false.
geronimo:
But you did sign as geronmo did you not? I was being flippant, because I assumed you yourself were joking and were asking the question ironically. I am very surprised that you would imagine I was thinking of you. I don't know where you could have got the idea. I will answer you this time with literalness and seriousness.
You were not in my mind. I was thinking of the kind of unreliable greenhouse sceptics and other outliers referred to both by Monty and by TBYJ, also discussed in my first BH discussion called Channelling dogginess.
I seem to be missing how anybody is able to split out CO2 effects from net temperature change. Taking out the known bits I can see, but with no means of checking what the known bits are, nor what the unknown bits are, I cannot see anything but an exercise in circular reasoning or at the very least fitting the data to the theory.
Now, obviously there is no objection to folks taking a shot at their best guess but one has to able to check, to compare results against some sort of observation. This is not happening. As soon as they get to the answer they want, whether high or low, they seem to stop looking.
So, tell me how that D&A thing works again. I think the last few times didn't take.
rhoda: They put all the natural forcings and the assumed forcing for CO2 into the models, then see what the temperature rise is. They then take out the CO2 component and see what the temperature rise is without it. I kid you not.
http://robertscribbler.wordpress.com/2014/03/05/sea-ice-loss-human-warming-places-earth-under-ongoing-fire-of-severe-weather-events-through-early-2014-likelihood-of-extremes-for-some-regions-increases-by-500/
Entropic,
It means I should read a Chicken Little Blog? I'm looking for something a little more scientific.
Andrew
Chandra,
I think you'll find, if you did but look, rather than the house burning down mankind suffers
WHEN icicles hang by the wall
And Dick the shepherd blows his nail,
And Tom bears logs into the hall,
And milk comes frozen home in pail;
When blood is nipt, and ways be foul,
Then nightly sings the staring owl
Tu-whoo!
Tu-whit! tu-whoo! A merry note!
While greasy Joan doth keel the pot.
When all around the wind doth blow,
And coughing drowns the parson's saw,
And birds sit brooding in the snow,
And Marian's nose looks red and raw;
When roasted crabs hiss in the bowl—
Then nightly sings the staring owl
Tu-whoo!
Tu-whit! tu-whoo! A merry note!
While greasy Joan doth keel the pot.
So far this inter-glacial warm has been good, and it's the cold that worries me, seeing as how we've
spentwasted billions in trying to stop it getting warmer based on dubious models; all of which are wrong.Entropic man
So this list isn't what is happening now but what we should use as indicators that something worse might happen. I thought we'd come to the conclusion that the data for sea-level rise wasn't good enough to make any decision on what was happening to that indicator. So we're now left with rainfall, again my understanding is that in a warmer world there is a higher atmospheric H2O content, ignoring for the moment the +ve/-ve feedback issue, that will lead to increased rainfall somewhere. We cannot say where or when (time of year) that will be and for us optimists may well be in currently arid areas in winter and early spring. leading to bumper harvests. Why paint it black when we just don't know.
Rhoda
It's hard to separate an effect when you don't know what that effect does. Hence the process of reduction and characterisation that I was talking about. It's nice to see others appreciate what it takes to actually do science properly.
As for Monty and Richard Betts who apparently think that sufficient information can be gleaned solely from paleoclimate approximations and theoretical assumptions, themselves heavily weighted on assumptions. Well, using that method they wouldn't have needed to build the LHC to look for the Higgs Boson. They could have just approximated by extrapolation.
And as yet Monty still hasn't answered my question about the basics of climate science. I would like to add to this what is the actual accuracy of proxy reconstructions. It's certainly not sub degree accuracy. It's unlikely that the temperature record itself has that accuracy.
And to address your quip about scientific illiteracy, dear Monty I'm a PhD in physics, I currently work as a safety critical software verification engineer but spent almost 9 years developing, building and flying plasma thrusters in space. I worked on the GOCE thruster system. Basically I'm a rocket scientist and one who has had dealings with NPL in London. So I know a thing or two about charactersation, metrology and accuracy. And of course the Scientific Method.
Something that based on your quips and jibes on here, you clearly don't. Or worse, you think you do.
Sadly, Ed Hawkins has resorted to wholesale censorship of comments on Piers Forster's piece.
I made several comments to those on the consensus side who quoted the recent Cowtan & Way paper as evidence of surface temperature trends.
Since we know from the leaked private Skeptical Science forum, where both Cowtan & Way were vocal activists, that the paper was conceived and executed as a deliberate SkS project to get around the "pause problem" by "taking down HADCRUT" - I find it bizarre that the paper is now being routinely referred to by serious scientists (including Tamsin) as the last word on surface temperature.
Apparently, pointing this out is beyond the realms of civilised discourse - so Ed has simply disappeared all my comments.
Bad Andrew
Refer to the reference list at the end of the post.
Euan Mears
Too much to answer briefly. We have very different world models.
Sandy S
My list is metrics by which to measure climate. Some are purely scientific. I doubt that anyone expects increasing DWR to set their hair on fire. :-)
Others have consequences for our civilisation.
You and others keep mentioning uncertainty. Why do you assume that uncertainty is your friend? It is equally possible that IPCC is underestimating the problem.
Foxgoose, you misrepresent me:
"There is of course increasing evidence it’s a slowdown, such as C&W itself (e.g. kriging method: 0.108 ± 0.073), but it’s not super-strong yet in my opinion.
Comment here.
Euan Mears
IPCC estimates TCR in the range 1 to 2.5C and ECS in the range 1.5 to 4.5C.
Lewis and Crok at GWPF estimate TCR of 1 to 2C and ECS of 1.25 to 3C
"Refer to the reference list at the end of the post."
I agree with you that the body of the post is not scientific.
Andrew
The Lewis & Crok paper is about the IPCC publication and its apparently misleading deliberations. It is not about climate sensitivity itself. Climate sensitivity employing energy balance is a climate science construct - it fits with their hypothesis on radiative energy transfer. Remember this?
“What if climate change appears to be just mainly a multi-decadal natural fluctuation? They'll kill us probably."
Isn't the jury still out on that one?
Ssat
You may remember Richard Feynman describing how he used to visualise his thinking.
I have a mental picture of the climate system as an extended version of the energy budget diagrams. It works well for me, without the need for hypothetical natural variations.
If you want proof of the science " beyond reasonable doubt" you probably won't get it. Science rarely works that tidily.
I don't think I'm misrepresenting you Tamsin.
I said:-
In your "Pause for thought" thread, you referred to the Cowtan & Way paper at least three times as "evidence" against the pause. In addition to the quote you have posted above, you made the following statements:-
and later…..
So, in a lengthy post devoted to the "pause" you brought up the Cowtan & Way paper three times, referring to it either as "increasing evidence" or "more evidence".
The point I tried to make to you there was that it's wrong to concentrate on a paper which is simply an interesting mathematical treatment of existing data and hold it up as "evidence" of anything.
It's very interesting to consider a parallel between that paper and the Lewis & Crok paper we're discussing here.
It's fair to say that both papers were produced by amateur scientists, outside the mainstream of consensus climate science, who thought they could improve on a particular generally accepted conclusion of the science.
Cowtan & Way used novel treatments of existing data to try and make the case that the HADCRUT data set was underestimating the current temperature trend because of geographical data limitations.
Several of the more open-minded sceptic commentators like Lucia said that the paper was mathematically viable and interesting piece of work.
Shortly afterwards, Cowtan & Way began to be regularly referenced in climate discussions by serious mainstream scientists like Schmidt & Rahmstorf as if it were now one of the established temperature data sets. I seem to remember Rahmstorf publishing a table where C&W had its own column alongside HADCRUT, GISS etc.
The point I have been trying to make is that's it's very odd that this peripheral, amateur piece of work has been seized on by consensus scientists and promoted ahead of the established results.
Contrast that with the treatment meted out by you and your colleagues to Lewis & Crok.
Rather than taking the time to read & digest the paper and make a sober technical judgement on it - we had an overnight "rapid rebuttal" of the paper, accompanied by mass tweeting from you, Richard, Ed & others - ignoring the author's conclusions completely and putting your own spin on one aspect to create the line "sceptics finally accept dangerous climate change".
One thing is for sure - hell will freeze over before any of you consensus crowd will casually refer to Lewis & Crok as "increasing evidence for lower climate sensitivity."
In short this whole episode is just another little cameo showing the politicisation and asymmetry of the whole climate debate.
Entropic man
Uncertainty, not knowing exactly what the future holds, to me means You don't know what you don't know * (which has been my response to questions like this since before Donald Rumsfeld came on the scene) also holds the warning that any money spent, time invested and labour expended will be wasted when the unexpected happens. In military circles I believe this comes under the maxim that no battle plan survives first contact with the enemy
* for climate models values all the current inputs and these models will, if the history of science is anything to go by, have a large number of unknown inputs which will be completely absent currently
Richard Betts wrote, in relation to the statement in my and Marcel Crok's report "Recent increases in greenhouse gas concentrations have been close to those in the middle two scenarios, RCP4.5 and RCP6, although emissions appear to have been increasing at a rate at or above that per the RCP8.5 scenario.":
"I'm a bit confused about that statement too. The second part is correct - CO2 emissions have indeed been at or above RCP8.5, see here (Slide 20) (Rud Istvan, please note!)
However I don't know where the first part statement comes from, because for the first 10-15 years or so of the RCP scenarios (starting at 2005) the CO2 concentrations of the different scenarios are virtually indistinguishable from one another - see here (inset - you may need to zoom in). This is because CO2 concentrations in any particular year are affected by the total of previous emissions (most of which are still in the atmosphere) more than the emissions in that year. Therefore if the observed concentrations are close to any of the scenarios in recent years, then they will be close to all scenarios."
I agree that the differences are not large up to 2012. The statement in the report was based on the concentration growth rates up to 2012. Starting from 2000, the rise in actual concentration (Mauna Loa) averaged 0.535% p.a. RCP4.5 is almost the same at 0.539% p.a.; RCP6.0 is 0.544%. RCP8.5 is higher at 0.551% p.a. So the statement is correct with respect to those figures, but the differences are pretty small. From 2009 to 2012 the position is similar but the differences are larger: actual 0.558% vs RCP4.5 0.554% (RCP6.0 is more like 0.54%) vs 0.599% RCP8.5. So looking at both periods the actual rise at Mauna Loa is dead in line with RCP4.5, and pretty close to RCP6.0, but clearly below RCP8.5 – by 2% since 2000 but by 7% since 2009. Not a large difference, but quite clear-cut.
The interesting question is to what extent this divergence may represent carbon cycle models being oversensitive as opposed to other influences (El Nina vs El Nino, deforestation rates, etc) . I've no view on this at present, but if the divergence continues it may point to carbon cycle models being oversensitive.
Foxgoose +1
Major tactical error by GPWF and Lewis & Crok.
You've agreed your prostitutes and you are now only arguing about the price. Your client will have the last word.
Doh! 'your' = 'you're'
Lapogus.
Nice graph. Note that the previous four interglacial peaked sharply and then started straight back down. This time temperatures stayed high.
I wonder what is different this time?
If you want proof of the science " beyond reasonable doubt" you probably won't get it. Science rarely works that tidily.
Mar 7, 2014 at 4:48 PM Entropic man
Come on EM less of the BS please.
Huge areas of science give evidence of what happens and how things work beyond all possible doubt.
Entropic:
It is on this basis that you wish to interfere in my life in a way which I see detrimental to it and to that of my children and grandchildren? Thank you for your encouragement to keep resisting *groupthink.
*Groupthink is a psychological phenomenon that occurs within a group of people, in which the desire for harmony or conformity in the group results in an incorrect or deviant decision-making outcome. Group members try to minimize conflict and reach a consensus decision without critical evaluation of alternative ideas or viewpoints, and by isolating themselves from outside influences.
Loyalty to the group requires individuals to avoid raising controversial issues or alternative solutions, and there is loss of individual creativity, uniqueness and independent thinking. The dysfunctional group dynamics of the "ingroup" produces an "illusion of invulnerability" (an inflated certainty that the right decision has been made). Thus the "ingroup" significantly overrates their own abilities in decision-making, and significantly underrates the abilities of their opponents (the "outgroup").