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The IPCC has announced (via a “leak” campaign only to selected media outlets, such as Reuters, NYT, WaPo) that they are now 95% certain. From Reuters:
Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities – chiefly the burning of fossil fuels – are the main cause of warming since the 1950s.
I’m glad they pinned down “…since the 1950s”, that’s important.
According to this MotherJones report:
According to Jonathan Lynn, who is head of communications at the IPCC, the organization expects that leaks will occur because report drafts wind up in so many different hands. Lynn cautions that “there’s no question that the final report will not be the same as the drafts.”
I’ve been in touch with IPCC secretariat Mr. Jonathan Lynn, and while he’s glad to point out issues on WUWT, neither he nor any of the media outlets that have the “leaked” report are willing to provide WUWT with a copy. No matter, we’ll simply go with what we know.
Here is the statement again, emphasis mine:
Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities – chiefly the burning of fossil fuels – are the main cause of warming since the 1950s.
OK, so here’s the 64 thousand dollar questions for IPCC cheerleaders:
- Which side is which time period?
- What caused the warming before CO2 became an issue to be essentially identical to the period when it is claimed to be the main driver?
- How is the IPCC 95% certain one side is caused by man and the other is not?
h/t to Burt Rutan, but I believe the original comparison concept was by Warren Meyer.
BTW, the answer should be obvious which is which due to the telltale 1997-1998 El Niño signature in one graph.
thingadonta says:
August 20, 2013 at 4:41 pm
There were few climate change jobs before 1950.
I think one might find that climate change attribution to humans corresponds with the number of paid climate change alarmists. But the good side is this, once the temperature fails to warm, the number of employed alarmists will fall, and so will the general attribution of climate change to humans.
You miss the point, like others here.
This is a political campaign and they intend to win now and the fact that you can show in 2018 that their arguments were wrong when they closed down all the power stations in 2012/2014/2015 and imposed stringent rules on industry, will not bring those powers stations back online, remove regulations, laws, governances and taxes. The entire reason for all the softening up of the populace with National Geographic stupidities and Reuters and CNN is that they need to get all their regulations and taxes in quickly as they know there is limited time.
The scientific arguments on what is meant by “95% certain” are similarly misjudged. Climate science never uses the correct units/metrics for anything. The AGW hypothesis is based on ‘trapping heat’ yet the climate ‘scientists’ use atmospheric temperature as the basis for their scare stories despite the fact this is not a measure of heat content. The climate ‘scientists’ use tree rings as indicators of heat content – despite the fact that there is no provable relationship, and on and on and on. But all these ‘colloquial’ metrics are used by the man in the street and they are effective with focus groups in a way that a scientific argument is not. The National Geographic front page of flooded Statue of Liberty will have huge effect on the public that have been similarly convinced that Sandy was a ‘superstorm’ when it was less than the 1938 Long Island hurricane. It is the PR campaign that they are winning hands down and correcting what they mean by 95% certainty in scientific terms will not have any effect because to the man in the street 95% certain means only 5% less than absolutely certain. That means that EPA regulations closing down industry and power stations will have more public (and therefore congressional) support ‘as we need these regulations or there will be more storms like Sandy and the floods will be half way up the skyscrapers next time’.
Now I want to see a number from the IPCC telling me the cause[s] of the temperature standstill with 95% certainty. Can they do this? If temps start to fall can they admit that co2 is NOT the main driver of climate?
Now see this graph showing 2 distinct warming periods.
There has been a 0.8C rise in global surface temperature since around 1880. Now take out the rise up to 1950 and what do you have left? Now take out the natural component since 1950 and what do you have left?
Now see this question from the BBC and the reply from Dr. Phil Jones at the Climate Research Unit.
The IPCC are a bunch of climate clowns.
To Anthony who writes:
I no longer assign any credibility to Scafetta’s model, its seems little more than hindcast curve fitting – Anthony
**************************
If you try to understand the meaning of the “little more” you would change opinion.
For example, you may understand that the “little more” includes careful hindcast tests that cover up to 10,000 year of data, the entire Holocene. A fact that was not fulfilled by any climate models.
Moreover, the methodology that I use is essentially equivalent to the models used to predict ocean tides.
Finally, you need to propose a credible scientific alternative to well justify your belief, if not, you simply express a personal belief which is only what it is, a personal “religious” belief based on lack of your imagination and scientific knowledge.
Let your reads to decide by themselves. A summary of my research is here:
Scafetta N., 2013. Solar and planetary oscillation control on climate change: hind-cast, forecast and a comparison with the CMIP5 GCMs. Energy & Environment 24(3-4), 455–496.
http://people.duke.edu/~ns2002/pdf/Scafetta_EE_2013.pdf
The proposition leaked is this one:
“It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951-2010”
note: In the IPCC vocabulary “extremely likely” means to have a 95% chance.
Now, according to GISTEMP the Global Land-Ocean Temperature Index has increased by 0.73°C in the half century between 1951 and 2010. However, there is a marked endpoint effect here, because 2010 was unusually warm (the next 2 years being about 0.1°C cooler). Therefore it is a bit more correct to calculate trend during this period, which turns out to be 0.111°C/decade, that is, 0.56°C for the entire period.
With this, we are ready to transform the statement above to another, logically equivalent one.
“There is a one in twenty chance that according to observations human influence on climate caused no more than 0.28°C increase in global average surface temperature from 1951-2010”
Please note that “human influence on climate”, beyond GHG emissions includes land use changes, a sharp decrease in sulphate emissions (a.k.a. “global brightening” due to clean air acts all over the developed world) and increasing black carbon (soot) production (mainly from ill maintained diesel engines and incomplete biomass burning) as well. All these influences tend to increase surface temperature, so the part due to GHGs can’t be more than 0.15°C. In the same period CO₂ content of the atmosphere increased by 33% of a doubling. Which means climate sensitivity to CO₂ doubling is less than 0.5°C. And that implies strong negative feedbacks, absolutely inconsistent with any computational climate model the IPCC relies on.
Even if all anthropogenic temperature increase is attributed to GHGs, observed sensitivity is still no more than 1°C, which rejects any positive feedback whatsoever.
Now, in a sane world conceptual models inconsistent with observations would be dropped immediately. Are they?
The only way out is to suppose an extremely long equilibration time (e-folding at ~ 1 century), that is, high effective heat capacity of the climate system. In that case the slow warming rate observed becomes consistent with a ~3°C equilibrium climate sensitivity. However, this escape route comes at a price. Effective heat capacity so high as to be able to make observations consistent with strong positive feedbacks (needed to raise long term climate sensitivity sufficiently) is inconsistent with both observations (ARGO measurements of Ocean Heat Content) and computational climate models. On top of that a long lag time would severely limit warming rate due to GHGs on multi decadal scales, which is not alarming enough, even if one chooses to deny both observations and theory.
TomRude says:
August 20, 2013 at 8:50 pm (Edit)
95%… so there are at least AR6 96%, AR7 97%, AR8 98%, AR9 99% and AR10 100% for UN bureaucrats although they may not stop there… AR12 102%?
————————————————————————————–
We could get Spinal Tap to play some theme music for the IPCC and we could turn up the volume all the way to 11
Does Global warming increase welfare?, if so, Ky is doing very well. 25% on it here.
If man is powerful and smart enough to trash the planet, then we will be poweful and smart enough to fix it. Problem solved
“Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published next month, say it is at least 95 percent likely that human activities – chiefly the burning of fossil fuels – are the main cause of warming since the 1950s.”
Shouldn’t that read:
“…it is at least 95 percent likely that human activities – chiefly placing weather stations near asphalt and cooling vents within urban heat islands, and massaging past temperatures to make them cooler – are the main cause(s) of “warming” since the 1950s.”
Re: massaging – see many of my earlier posts, or go to NWS BWI (or other stations) and add up any month’s means 1981-2010, divide by 30, and see that it somehow comes out higher than the 30 year climatic “normals”. Funny how that happens.
Neither. Both graphs demonstrate the well-known land temperature teleconnections with ENSO events in the Pacific.
The experts are 95% convinced that their expertise is worth paying for. Quelle surprise.
You may have missed an important detail in the leaked draft. They are now 95% sure that 50% of the warming is manmade. They could have made it 100% if they had turned down the man made percentage.
Keitho says:
August 21, 2013 at 6:29 am
TomRude says:
August 20, 2013 at 8:50 pm (Edit)
95%… so there are at least AR6 96%, AR7 97%, AR8 98%, AR9 99% and AR10 100% for UN bureaucrats although they may not stop there… AR12 102%?
————————————————————————————–
We could get Spinal Tap to play some theme music for the IPCC and we could turn up the volume all the way to 11
___________________________________________________
Thanks Keitho for giving me the opening for, once again, posting absolutely the greatest single thing that Global Warming has produced to date: Spinal Tap and Every Bassist in the Known Universe at Live Earth.
http://youtu.be/iN42uzNFVmQ
So the IPCC has found that the probability of at least half of the global warming that has occurred since the 1950s being man-made is at least 95%, has it? I shall believe that when I see the proof and not before!
I do not expect the IPCC to produce any real scientific proof of its claim though of course. That’s not just because I believe the IPCC is an incorrigibly dishonest and corrupt political organization that would solemnly declare that it is 95% likely that the Moon is made of green cheese if it thought that doing so would advance its political agenda in some way. It is also because I think no human organization of any kind would have a snowball’s chance in hell of being able to prove it at the infantile stage of development that modern climate science has yet reached.
I got a sense of the vastness of the scientific challenge of proving man-made global warming recently when I contemplated the IPCC’s proposition and saw that it actually consists of four component propositions that are independent of one another and which would all need to be proved beyond reasonable doubt separately. Because of their independence, their individual probabilities of being correct must be multiplied together to produce the likelihood of their overall correctness, which the IPCC is ostensibly claiming to be over 95%. This means that their individual probabilities must each be over 95% to begin with. (If the individual probabilities were equal they would have to be over 98.7% each.)
The four component propositions that I identified were:
1. That a specific amount of global warming has occurred since the 1950s;
2. That at least half of this specified amount of global warming has been caused by a specific increase in the magnitude of the atmospheric greenhouse effect;
3. That the perceived increase in the magnitude of the greenhouse effect has been caused by a specific increase in the amount of atmospheric carbon dioxide;
4. That the specified increase in atmospheric CO2 is mainly the result of human CO2 emissions.
Now although these four component propositions are logically independent of one another, in another sense they are hierarchically dependent because each proposition can only be True if all of the ones that precede it are True first. That is to say, if (1) is False then (2), (3) and (4) are automatically False also; if (2) is False then (3) and (4) are automatically False too; and if (3) is False then so is (4) likewise. But it only takes any one component proposition to be False for the whole proposition to be False.
To me this situation appears to present the IPCC with a Herculean scientific challenge and easy pickings for AGW-sceptics, especially when you consider that each component proposition must be proven to at least the 95% level of statistical significance and that at least three of them would need to be proven to a higher level. Take the first component proposition for example. How could the IPCC prove to the 95% level of probability that a specific amount of global warming has occurred since the 1950s when the global temperature records do not provide accurate recordings of the global mean temperature to that level of confidence to begin with? And each of the other component propositions is fraught with other similarly-intractable problems of a disturbingly fundamental kind too. I think the IPCC would be extremely hard put to produce proof at, say, the 99% level for any one of them, let alone proof at the 95% level for the whole set.
However the IPCC appears to be going for broke over this so I look forward to examining the scientific grounds for its astonishing claim when the first part of AR5 is finally published. (I shall have popcorn at the ready too.)
Either an idiot did the statistical analysis or a P.O.S. pawn of the political make money on global warming bandwagon who calls him/herself a scientist (prostitute) did the work. What a ship of fools.
What is the source of information for the graphs? Annual HadCRUT3 shows the ~2008 La Nina as having warmer temperature overall than the ~2000 one.
Also, why is the latter one stopped very near depths of a roughly decade-class Lina (or a worse one according what you show), and the ~2005 height of the heat was followed by less cooling than the WWII warm period (according to smoothed annual HadCRUT3)?
Here’s another such scientific “consensus” that sounds wonderfully similar: The Inquisition’s “panel of experts” was 100 percent certain, based on Ptolemy’s models and righteous thinking, that the earth occupied the center of the universe, whereas Galileo, a seventeenth century ‘denier’, supported the Copernican view of a heliocentric system based on actual observation.
Kiwi Sceptic August 21, 2013 at 10:12 pm
Here’s another such scientific “consensus” that sounds wonderfully similar: The Inquisition’s “panel of experts” was 100 percent certain, based on Ptolemy’s models and righteous thinking, that the earth occupied the center of the universe, whereas Galileo, a seventeenth century ‘denier’, supported the Copernican view of a heliocentric system based on actual observation.
That’s unfair to Ptolemy and to those who used his model. It was actually useful! Would you say that the climate models are actually useful? What’s this “righteous thinking”? Are you suggesting that Ptolemy was a Christian? That’s not likely. He died in 168 AD.
Galileo’s relevant observation was that the moons of Jupiter orbit Jupiter, which showed that not all “heavy” objects orbit the earth. This only made it possible that the earth orbits the sun; it came nowhere near proving it. One objection to heliocentrism was that the fixed stars didn’t show parallax. Obviously that’s formidable. The reason they didn’t show it was that astronomers could not measure it finely enough, but the astronomers could not have known that. It was first observed in the late 1830s, more than 200 years after Galileo had done his work.
It would be from tallying the relative contibutions of various forcings, wouldn’t it?
(Now checking the leaked draft report)
Ch 10: Attribution
Which includes observed natural (eg, solar, volcanic) and anthropogenic (eg, GHG, aerosol) drivers.
Delving further into question 3 – AR5 attaches no particular confidence to pre-1950 attribution (data is sparser for that period), but posits a combination of solar and GHG forcing (both positive). Solar forcing has been insignificant for the post-1950s period, which may be partly why they attach high confidence to anthropogenic causes since then.
Both AR4 and AR5 (leaked draft) concur on anthropogenic forcing being the main driver the since the mid-20th century.
AR4 SPM – “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”
AR5 SPM – “It is extremely likely that human activities have caused more than half of the observed increase in global average surface temperature since the 1950s.”
Very little has changed between drafts, except that confidence is a bit higher for the claim.
barry:
re your post at August 22, 2013 at 6:57 am
http://wattsupwiththat.com/2013/08/20/when-somebody-hits-you-with-that-new-ipcc-is-95-certain-talking-point-show-them-this/#comment-1397047
The IPCC attribution studies are anti-scientific nonsense.
In an attribution study the system is assumed to be behaving in response to suggested mechanism(s) that is modeled, and the behaviour of the model is compared to the empirical data. If the model cannot emulate the empirical data then there is reason to suppose that the suggested mechanism is not the cause (or at least not the sole cause) of the changes recorded in the empirical data.
It is important to note that attribution studies can only be used to reject hypothesis that a mechanism is a cause for an observed effect. Ability to attribute a suggested cause to an effect is not evidence that the suggested cause is the real cause in part or in whole.
But the IPCC assumes that an ability to attribute an anthropogenic effect to explain what is not known is evidence that the anthropogenic effect is real.
This is similar to assuming that an ability to attribute an effect of witches to explain what is not known is evidence that the effect of witches is real.
In reality, all the IPCC’s attribution studies show is that either
(a) the putative anthropogenic effect cannot be rejected as being a possible cause of what is not known
OR
(b) the models (i.e. the understandings of climate built-in to the models) are wrong.
As you say of the AR4 and AR5
except that “confidence” should be “the unjustifiable stated confidence”.
Richard
Richard,
Attribution studies apply observed forcings and physics to modeling and compare to observed responses (like temperature). There is no empirical basis for the supernatural powers of witches. I am a little unclear of some of your argumentation. If you are saying that models fail to take into account unknown unknowns, then yes, obviously. But invoking such is uncomfortably similar to mystical arguments. We don’t know what causes gravity, but we make sufficiently useful models of it to navigate spacecraft to asteroids and planets in the solar system. Our understandings of things is always limited but that does not make them useless. As far as i can make out, IPCC has determined that that of all the known knowns, the dominant cause of global warming since 1950 is anthropogenic GHGs. Put another way, they are saying that it is extremely likely that anthropogenic GHGs have caused >50% of the warming since the mid-20th century. That doesn’t seem overly-confident on the surface. That still leaves nearly half of the warming to potentially have been caused by natural forces. It isn’t the sun, it isn’t volcanic activity, and long-term ocean atmosphere fluctuations (like the AMO) appear to lag global temperature rises, indicating that either those systems are responding to global temperature, or that the effects are local. In this light, the IPCC claim doesn’t seem so extreme. They are not saying, for example, that 95% of the warming since 1950 is anthropogenic in origin, only more than half.
These two graphs are actually two parts of one continuous graph that shows a clear warming trend. Someone cut the graph in two and slid the right half “down” to make it appear that they’re identical. They conveniently erased the temperature scale on the left, because obviously it wouldn’t match. This is purposefully misleading, akin to a lie, and calls into question the veracity and agenda of this website. Check the original graph yourself.
REPLY: Nope, sorry, neither misleading nor a lie. It shows that warming trends decades apart are identical, the only difference being the amount of Co2 in the atmosphere. That’s the point, feel free to be as upset about it as you wish. – Anthony
Smoking Frog says: August 22, 2013 at 5:44 am
“That’s unfair to Ptolemy and to those who used his model. It was actually useful! Would you say that the climate models are actually useful? What’s this “righteous thinking”? Are you suggesting that Ptolemy was a Christian? That’s not likely. He died in 168 AD.”
You’re missing the point. No I’m not saying Ptolemy was a Christian, nor am I saying his models weren’t useful for the purposes of describing what they thought were seeing. I’m saying that the “consensus” view of the universe at the time, based entirely upon Ptolemy’s ungainly models and religious attitudes, was wrong. Hence the “righteous thinking”. The Roman Church at the time insisted that this view of a geo-centric universe was not only right, but that it was blasphemous even to argue the opposite. The Inquisition enforced acceptance of this “consensus” view while flying in the face of clear observable evidence presented by the likes of Copernicus and Galileo that it wasn’t.
THAT is the point.
Not much has changed since the time of Galileo because these attitudes are clearly still prevalent.
science works @ur momisugly here.
The two graphs show similar amounts of warming for two different periods. Anthony is asking how the IPCC are confident anthropogenic GHGs are the main driver for the latter period but not the earlier period. A simple explanation is that the earlier period has less greenhouse forcing but more contribution from other sources, like solar, with a caveat that the data is not as clear for the early 20th century. IPCC cannot be sure that GHG forcing is responsible for more than half of the early period, so they attach no particular confidence to attribution for that period, whereas solar, volcanic and other forcings appear to be dwarfed by a greater accumulation of GHGs in the latter period. When they model observed forcings, they do not get the temperature rise of the 2nd half of the 20th century without including GHG forcing in the models.
barry says:
August 22, 2013 at 6:14 pm
Hmmn. Seems that Dr Sval – and many others – have established through Be10 measurements, and other real world/non-IPCC-invented-on-the-fly-proxies that solar changes could account for no more than 0.1% deviations form today’s average solar constant. The worldwide increase in global temperature in early 20th century must have been natural.
Oh. And there have been no volcanoes the past 16 years either. The worldwide pause in global temperature in the early 21th century must have been natural.
And no one has actually produced any “measured” world-wide aerosol count increases sufficient to “stop” that mid 20th warming between 1940 and 1975. The worldwide pause in global temperature in the mid 20th century must have been natural.
And no one has actually produced any “measured” north hemisphere-wide aerosol count increases sufficient to “stop” the recent 20th warming. The worldwide pause in global temperature in the early 21th century must have been natural.
Gee. do you wonder why I claim the late 20th century warming was Mann-made?
RACookPE1978,
The conclusion doesn’t follow from the premise. If solar effects are small, then this discounts that natural source as being a main driver. But regardless of the magnitude of impact, solar influence has been flat or slightly declining since the mid-20th century. Different to the early 20th century when a positive forcing is estimated.
Single events do not cause long-term change. The Pinatubo effect lasted less than 5 years. Volcanic forcing on climatic scales is measured by series of events. There has been little change in long-term volcanic activity over the past century, with a small number of single events, so volcanoes are not a signficant driver.
Yes, data is limited on aerosols. Satellites have been able to capture world-wide aerosol bulk amounts since the 1980s, but not individual species. Downwind inventories are sparse, but the total of estimates points to a negligible contribution or slight warming inlfuence in the last quarter of the 20th century, even allowing for error bars. You can check for range estimates and confidence intervals in AR4 or the leaked report.
We have good estimates on volcanic solar, and GHG contributions since the 1950s. Clouds and aerosols remain areas of significant uncertainty, but these IPCC posits the range is constrained sufficiently to estimate that the combined contribution to warming is less than 50%. Check report/s for details.
(Note, I’m not saying these figures are the final truth, merely reporting what the IPCC says in answer to Anthony’s question, and your points. For example, there *is* world-wide measurement of aerosol influence from satellites, contrary to your blanket assertion, but prior to that data is much more limited. Gaps in knowledge are not the same as knowing nothing)
It is strange that you point to uncertainty in the data, and then confidently espouse causes for climate change. How is that not contradictory?
“We don’t know enough to say whether recent climate changes are man-made or natural, therefore they must be natural.”
Huh?
From a purely neutral point of view, I’d have more confidence in conclusions derived from years of research by numerous researchers looking at these issues in great detail, even while maintaining reasonable doubt, as honest skeptics must.