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)
Great work from Nic and Marcel and a real coup getting Judy Curry to contribute.
Now the hard bit. Encouraging the politicians, particularly the few who decide energy policy, to read it and even harder to get them to understand the implications.
Only blackouts (brown) and price escalation will convince them to change tack.
I'm too old for it to matter much but my children and grandkids will certainly be badly hit by the the scientifically illiterates that rule us.
As I said on Judith's blog, I take this as a positive step because the debate on anthropogenic climate change is now finally shifting away from distractions such as whether warming is “statistically significant”, or whether warming has gone away, or whether humans have an influence on climate. 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?
I note that Lewis & Crok expect the political target of 2 degrees C warming to be exceeded by 2081-2100 under RCP8.5. Now it seems pretty much everyone agrees that this level of warming is on the cards, we need to assess the implications of this to help figure out what to do.
Dredge Richard. Dredge
" 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?"
I'm sorry Richard, but it's always been in those areas hasn't it? Except, of course, that the IPCC has stated,without a scintilla of observational evidence, that the human influence is 95% certain to have been major, that the change we can expect will lead to droughts, sea level rises, heat waves and any number of catastrophes based on what's happening at any particular point in time, etc. etc. and that the risks are diabolical.
In all of these they have been supported both vociferously and taciturnly by the climate science community and the scientific establishment. So, much as I appreciate your own contribution to the debate please don't take the opportunity to pretend that the whole thing hasn't, or may have been (the engineer in me), over-hyped, not just by the climate science community, but by the whole of the scientific establishment.
I also believe you missed the "what can we do about it" bit out of where the conversation should go. For me that's been the biggest issue of all. It's where the enviros and socialists are getting the opportunity to micro manage people's lives on the back of the threats supported wholeheartedly and politically by the scientific community. It is indeed the whole battleground, because that's where the control lies for the control freaks. It is my view that if we ever have a rational discussion taking into the question "what we can do about it", the answer is "bugger all" even if we give the environmentalists and leftists the power they yearn to get from this scare.
Betts: "Now it seems pretty much everyone agrees that this level of warming is on the cards, we need to assess the implications of this to help figure out what to do."
Nothing would be the best choice. Besides, most of the warming blamed on CO2 is just the AMO and PDO,
"I note that Lewis & Crok expect the political target of 2 degrees C warming to be exceeded by 2081-2100 under RCP8.5."
And if the expected warming doesn't materialize, climate scientists in the year 2100 can simply adjust today's temperatures down by 2 degrees C. So it's pretty much a certainty, yeah.
H H Lamb said that by reference to the comparison of modelling estimates with empirical data on this chart: http://enthusiasmscepticismscience.wordpress.com/h-h-lamb/1982_1995_lamb_projection/#main
He said that in 1982. Maybe this time someone will listen.
IPCC is UN(EP) established and based. And must for that reason alone support the UNFCCC 100%. The basis for the models is mostly the UNFCCC. Critique of the models also means critique of the UNFCCC. And that is not going to happend.
Excellent report and really good news. Take out the positive feedback assumptions and the "problem" of AGW disappears. Now the Met Office will be advising the Government to get rid of all those useless wind turbines, solar panels, biomass power stations, wave projects, tidal projects, CCS and all the other useless technologies. They will be advising the Government to get rid of everything labelled green and all the useless climate change organisations. They will be advising the Government to stop doing research into man-made climate change because a real amateur scientist can do it all by himself. Yes, really they will. I know they will.
It is good to see the IPCC's junk science being questioned by Crok and Lewis, but I would argue that even a Climate sensitivity of 1.75C per doubling is way too high. Good long term datasets and ice core proxies suggests the 20th Century 'Warm period' was just a continuation of the rebound from the Little Ice Age, and nothing unusual or unprecedented: http://snag.gy/BztF1.jpg, and http://oi49.tinypic.com/rc93fa.jpg, and even this rise has been inflated by UHI, dubious data selection: e.g.
Evidence of UHI in Crutem3
climate coincidence - surface station closures in 1990 - McKittrick's graph
and bare-faced fraudulent adjustments of historic temperatures to make the past look colder - GISS US temperatures blink graph (before and after adjustments).
Brazil (GISS v2 verses GISS v3)
source: GISS v2 - http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=303825860000&dt=1&ds=1
source: GISS v3 - http://data.giss.nasa.gov/cgi-bin/gistemp/show_station.cgi?id=303825860000&dt=1&ds=14
Australia - Alice Springs,
Darwin
Arctic - GISS revising history again
The evidence suggests that variation in tropical cloud cover alone can explain the late 20th warming.
Hence I remain to be convinced that CO2 is anything more than a very minor player, and give it 0.25C - 0.5C per doubling at the most.
Richard Betts, care to comment or try to explain the elephants in the room, i.e. UHI, the fraudulent historic adjustments, and or the tropical insolation graph?
And before anyone suggests that I must be a conspiracy nutter to suggest that the IPCC's CO2 AGW thesis is a massive scam, it only takes a half a dozen influential people in the right positions (e.g. Schneider, Hansen, Jones, Mikey & Gavin) to put some wheels on an idea, and get it rolling. 97% of the rest will follow thanks to groupthink and then institutional inertia will do the rest. Hubert Lamb must be turning in his grave at what his students instigated.
These climategate2 emails seem apposite to the CS issue:
and let's not forget one of the classics from climategate1:
A response is out :
http://www.climate-lab-book.ac.uk/2014/gwpf/?utm_source=rss&utm_medium=rss&utm_campaign=gwpf
The BBC hasn't picked up on the good news yet. It's still all bad news from the BBC.
Phillip - the BBC didn't even mention climategate for a week, and they effectively hid the IPCC's "Himalayan glaciers will melt by 2035" mistake on an obscure page on the Asian section of their website. The BBC exercises bias by censorship of any news which does not fit their agenda, as much as the actual colour of its output.
Richard Betts
Glad that you agree that this paper is important to the climate debate, but what about the science. Are we to presume now that the UKMO decadal (or 5 year) forecast will be subject to a model rerun with a climate sensitivity to CO2 halved? Obviously with so many current political and industrial planning decisions being influenced by the forecast this will be upper most in the thoughts of the scientists at Exeter, more so than the climate in 2100.
Great to see the GWPF acknowledging substantial further warming is expected. Actually, the Lewis & Crok report predicts a best estimate of 3C rise (above pre-industrial) by 2100 under business-as-usual RCP 8.5. [It is 2C under the RCP 6.0 scenario.]
Ed.
It's very amusing to see the excited response to lukewarmers being lukewarmers.
Warmists don't want good news. They only want bad news to prove their beliefs correct.
This example here in Guardian article on UN climate chief Christiana Figueres:
http://www.theguardian.com/environment/2014/mar/05/extreme-weather-climate-change-political-christiana-figueres-un
"It's unfortunate that we have to have these weather events, but there is a silver lining if you wish, that they remind us is solving climate change, addressing climate change in a timely way, is not a partisan issue."
Non-partisan? So what she's saying is 'the more people affected by extreme weather the better' and 'the better chance of her glowing in a successful and lucrative career'.
Its perhaps ironic that Figueres was the home town of Salvador Dali, the father of surrealism.
I'm still not really sure where the 'climate sensitivity' from observations get the estimates from. Just from the 20th century is a 60 year period 1910-1970 where it appears from the observations that temperature and CO2 don't correlate well at all.
Lord Beaverbrook
Don't expect an answer, from my observations Richard Betts operates here in a drive-by mode similar to Steve Mosher at WUWT.
It has to be remembered that unvalidated climate models have no worth. Factor in the sun's increasing inactivity and the ocean cycles and we are in for cooling rather than warming. A proper risk assessment would indicate that any money spent should be in preparation for adaptation to all the adverse consequences a cooling climate will bring.
actually you might as well take the 100 years from say 1870-1970 to say the correlation is very bad. I can't see anyway you would get a 'sensitivity' of 1.5-2 from that data.
Look, at some point I really hope people start doing science rather than theory.
It's great that Nic and Marcel have produced this report. The problem is that it assumes CO2 climate sensitivity exists in the first place. You are taking correlation as causation.
Say there is CO2 climate sensitivity. What's the first thing you do? You go into lab and show that CO2 can alter the temperature of its surroundings like your theory says. It will do in large amounts because of specific heat capacity but for AGW numbers which is supposed to be radiation dominant you need to show this. You need to also eliminate by careful experiment all other factors eg convection.
Then you have an ideal estimate of climate sensitivity. Only then. You take this and go look at the whole climate system and ascertain how much this value changes due to other effects.
What you don't do is take the system, make an assumption then produce a value and say look this is a real value.
Effectively what's been done here is to say God created the world in 3 days not 6.
Like I said at some point people will take their gaze away from this circus like Patrick Moore and realise they are doing knowledge and science a disservice. This type of report doesn't help.
As Ed Hawkins' comment makes clear, even at a lower sensitivity, there are emissions scenarios that will likely lead to a temperature increase of 2C or more by 2100. Such an increase is regarded a "dangerous" under the Kyoto Protocol. Thus, lukewarmers are still left with the question of whether it makes policy sense to pursue an emissions trajectory that keeps the likely rise in temperature at less than 2C.
The only argument against this, it seems to me, is that at rise of 2C is not, in fact, dangerous. There's been relatively little attention given on this blog to what temperature rise would be dangerous: 2C, 3C, 4C? I for one would be interested to see more on this.
@Ed Hawkins - Where does the figure of 2.1 come from, could you include the quote from the report please ?
(Genuine question, not trolling.)
Thanks.
Rob Burton
I'm with you on that, the correlation during the last 20 years isn't that great either. So we had a period of about 20 - 30 years where the correlation was quite good probably by coincidence. I bet anyone with a large government grant could find all sorts of 20-30 year pseudo-correlations in the 20th century.
RichieRich
Dangerous to man, the world in general or glaciers in the high Andes?
Congratulations Nic, Marcel, Andrew, Benny, Nigel and all!
RichieRich (and others!)
Why?As far as I know 2° has about the same scientific validity as 'five-a-day' and '21 units a week'. I.e. precious little.
Along with "we must cut our sugar intake by 50%" and "protein is as deadly as cigarette smoke".
What we are talking here is social control not science.
labogus
Totally agree.
In which I read that the longer it persists or even down-turns, the lower will be TCR.
The longer version of the report is here.
Please read this version, in particular the conclusion of the report, which some people seem to be trying to spin:
@ Mike Jackson
My point is this. If lukewarmers want to see no climate-policy measures to reduce emissions, it's not enough to claim that sensitivity is low. Because, even at low sensitivity, temp could go above 2C. In addition, it has to be argued that 2C isn't dangerous.
Now you may not regard 2C as dangerous, but simply to dismiss the 2C target as no more valid than five-a-day will cut no policy ice. My point is that, if lukewarmers want traction politically, analysis of the 2C target that's as detailed at the analysis Nic Lewis has done on sensitivity is required.
Thank you Andrew, Nic, Marcel and the GWPF.
And just why is a 2C rise "dangerous"?
Is this because it is (evidence please), or because this 2C figure was literally plucked from Pachuari's behind at one of the IPCC's "love-ins" (climate summits)?
Richie Rich
http://www.econ.yale.edu/~nordhaus/homepage/documents/Tol_impacts_JEP_2009.pdf
By Tol. Net positive to 2.3 deg C.
@ Bitter&Twisted
Whilst a bit of snark might make you feel better, it simply doesn't move anything forward politically. So I'll say what I said to Mike Jackson.
@ ssat
Thanks for the link. I'm well aware of Richard Tol's paper. But one paper by one author doesn't give political traction. I'm simply suggesting that the 2C target is an area that sceptics/lukewarmers might want to give more attention to. Is this really a controversial suggestion?
"As I said on Judith's blog, I take this as a positive step because the debate on anthropogenic climate change is now finally shifting away from distractions such as whether warming is “statistically significant”, or whether warming has gone away, or whether humans have an influence on climate. 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?"
No Dr Betts the real dabate has ALWAYS been about how sensitive is the climate to CO2. It was never been about has the planet warmed or whether man influences it!
Institutions like the Met Office have played their part in obscuring the debate.
Mar 6, 2014 at 9:36 AM | RichieRich
Wouldn't something like shale gas ending up being a useful energy resource coupled with a energy shortage in the UK be good enough for the politicians to change policies fairly quickly. I'm sure the correct science can come along to support the decision.
Good to see that 'skeptics' are finally moving away from: 'it's not happening' or 'CO2 isn't a greenhouse gas' to a more scientifically literate position. It's taken a long time and they have had to be dragged kicking and screaming here....but we should be thankful for small mercies.
Thanks to Nic Lewis' work we can all now debate whether 2-3 C warming by the end of the century is 'dangerous' or not!
The answer will be 'Yes'.
First, let me say that just because you've accounted for everything and you can find temperature change over a time period and link it to CO2 levels, you have not proved that this is ECS. It is merely the sum of unknown unknowns. It is a valid method for capping the estimate of ECS, but it does not show that there really is such a thing as ECS measurable globally over centennial timescales. I agree with Mickey Corbett.
However, now that RB is beginning to get on the same page as the rest of us, let me ask a couple of my usual naive questions.
Is climate sensitivity a genuine emergent property of the models, or is the range pretty much fixed by assumptions made at the programming stage?
Are there any intermediate measurements in between increased CO2 and global mean temps which might be checked against reality to determine to what extent any temp delta is attributable to CO2?
Judith Curry says: "I think it is important to put forward alternative assessments of the key elements of the climate change debate — alternative to reports issued by the IPCC, the UK MetOffice, and the RS/NAS."
I couldn't possibly comment.
Oh, two degrees? Pretty much the equivalent of living two hundred miles equator-wards of where you are now. Or maybe an hour on a nice day. Or a week or two nearer peak summer heat. Absolutely no biggie on first look. If you think it's dangerous, isn't that up for you to prove? I am looking forward to the climate of Oxfordshire approaching that of Bordeaux. Except I don't really believe that. Last time we had a seriously different climate was when you could see the glaciers from here.
Mar 6, 2014 at 10:17 AM | Monty
'Good to see that 'skeptics' are finally moving away from: 'it's not happening' or 'CO2 isn't a greenhouse gas' to a more scientifically literate position. It's taken a long time and they have had to be dragged kicking and screaming here....but we should be thankful for small mercies.'
That has never been the skeptics' position. Stop making things up.
rhoda - Oh, two degrees? Pretty much the equivalent of living two hundred miles equator-wards of where you are now. Or maybe an hour on a nice day. Or a week or two nearer peak summer heat. Absolutely no biggie on first look. If you think it's dangerous, isn't that up for you to prove? I am looking forward to the climate of Oxfordshire approaching that of Bordeaux. Except I don't really believe that. Last time we had a seriously different climate was when you could see the glaciers from here.
Does that means those living in areas that are more susceptible to changes in temperature will be adversely effected?
RichieRich says "Now you may not regard 2C as dangerous, but simply to dismiss the 2C target as no more valid than five-a-day will cut no policy ice. My point is that, if lukewarmers want traction politically, analysis of the 2C target that's as detailed at the analysis Nic Lewis has done on sensitivity is required."
I'm still waiting for evidence that it is. Put up or shut up.
"Now it seems pretty much everyone agrees that...."
Don't over egg the pudding Richard (Betts). Stick with specific verifiable claims and don't speak for "everyone" unless you've consulted with them and have their clear consent and agreement. "Everyone" is a lot of people.
Steve Jones wrote: "That has never been the skeptics' position. Stop making things up".
Are you new to the internet? You are kidding, right?
RichieRich, I think Bitter&Twisted is missing your point.
RitcheRich & Monty - So we are still all going to die by teatime then? Ffs, 2C is not even slightly dangerous, we have been there before, many times, and these warm periods tend to associated with growth of civilisations - GISP Lappi / Alley graph with HADCRUT4 appended.
But as Rhoda says, I will believe that we are heading for 2C rise when I see it.
Enjoy the Holocene while it lasts.