Bishop Hill Why four degrees?
Dec 2, 2010 Climate: Surface Climate: WG2 Climate: WG3 There was some interesting engagement between commenters on the Kevin Anderson thread and the good professor himself. Hat tips to all concerned.
My own contribution to the comments was limited - having been snowbound since the weekend, there was a certain amount of merrymaking in the village last night by way of cheering ourselves up. The one comment I did make was to note that a temperature rise of four degrees by 2060 is extremely high in the light of the temperatures observed since the millennium. Prof Anderson's response was to refer commenters to the Phil Trans A special edition that started the thread off.
If we look at the introductory article, by New et al., there is indeed some explanation of why four degrees is considered a number that should be discussed.
The 2009 Copenhagen Accord recognized the scientific view ‘that the increase in global temperature should be below 2 degrees Celsius’ despite growing views that this might be too high. At the same time, the continued rise in greenhouse gas emissions in the past decade and the delays in a comprehensive global emissions reduction agreement have made achieving this target extremely difficult, arguably impossible, raising the likelihood of global temperature rises of 3◦C or 4◦C within this century. Yet, there are few studies that assess the potential impacts and consequences of a warming of 4◦C or greater in a systematic manner. Papers in this themed issue provide an initial picture of the challenges facing a world that warms by 4◦C or more...
In other words, we think that CO2 emissions are going to be higher than expected therefore we need to look at higher temperature rises.
But hold on, my point was that 4 degrees by 2060 (perhaps 5 or 6 degrees per century) is high in the light of recent temperature trends. As readers of Lucia's blog know, even a trend of 2 degrees per century is on the cusp of falsification, so 5 or 6 is surely falsified at a very level of confidence.
If the trend is already falsified what is the point of looking at it, other than as part of a PR campaign?
Reader Comments (26)
"If the trend is already falsified what is the point of looking at it, other than as part of a PR campaign?"
Ding-ding, we have a winner!
2 degrees just isn't scary enough.
Slightly off thread but related.
Last night giving the Royal Television Society Huw Weldon lecture, Brian Cox praised peer review as promoting the scientific consensus and therefore representing some form of scientific truth on a given subject. He described The Great Global Warming Swindle as "total bollocks". This despite his earlier eloquent description of the scietific method of hypothesis, falsification and so on.
Interesting in the light of the new O'Donnell, Lewis, McIntyre and Condon paper that has refuted Steig and the process the authors had to go through. Cox failed to mention that peer review is not a review of the "science" as such and fails totally with most pro AGW papers. See WUWT and The Air Vent.
It's curious that so many eminent scientists can face in the wrong direction at once. Rather like the group think that takes place in big companies when pursuing an obviously doomed project because too much face will be lost in admitting fault.
Cheers
Paul
I have been stuggling to understand how these clearly deniable forecasts get stuck into the MSM publications and yesterday, from a deep corner of my mind I recalled a Beachcomber article in which the great man foresaw the art of climate predictions as we know them today. The phrase was:
"If we had some bacon we could have some bacon and eggs, if we had some eggs."
MSM response: "Wait a minute, are you saying if we had some bacon we could have bacon and eggs if we had some eggs?"
Reply: "Yes."
MSM: "That means we will be able to eat as much bacon and eggs as we like if we had them?"
Reply: "Yes."
MSM: "If we ate as much bacon and eggs as we like we'd become obese wouldn't we?"
Reply: "Yes."
Headline: BEACHCOMBER FORECASTS MASS OBESITY AS FATTIES GORGE BACON AND EGGS.
h/t to H. B Morton
I do think Anderson pre-Cancun comments that 2C now represents the threshold of extremely dangerous climate change undermines his own research/propaganda on the signifigance of 4C.
As Bish and other readers have noted even 2C is very unlikely based on current trends, 4C, well, that is an almighty flight of fantasy.
You see this figure is based on ideology and not science, that is why it is also flexible.
You need an environmental scare based on a so-called temperature tipping point all you need do is to fund Prof Anderson and his Tyndall colleagues to report on it. That is exactly what Friends of the Earth did.
Prof Anderson is a CAGW zealot and he operates the Tyndall Climate Scaremongering Centre and Tipping-Points-R-Us business. He is so hopelessly compromised he can't see it.
.......... and he runs a campervan. I rest my case.
'In other words, we think that CO2 emissions are going to be higher than expected therefore we need to look at higher temperature rises.'
I would be more impressed by papers contemplating the effects of a fall in temperature of 2 degrees by 2100. Much has been debated about the effects of a rise in temperatures but for risk analysis one must consider and prepare for all eventualities.
Of course any reputable climate scientist could publicly state that this eventuality is not even worth contemplating which may ensure that their name goes down in the annuls of history, but not for the reason that they would presume!
Prof Mike Lockwood of the department of meteorology at the University of Reading.
Nominee for the December calendar spot.
http://www.irishtimes.com/newspaper/ireland/2010/1130/1224284431435.html
'WE ARE likely to experience several years of colder winters with more frequent cold spells similar to the current conditions, according to a UK climate expert.'
Lord B @ 9.04.
I was going to say the same thing. I am more worried about a 2degC fall.
Ah well, back to snow-shovelling here in Devon. Cut-off from civilisation for the third winter!
Bish
Thanks for the above. Too full of a cold and too tired last night to get it straight in the comments.
The 100 trillion dollar question is this. Why are these people lying ?
The 100 trillion dollar question is this. Why are these people lying ?
Err the reward of 100 Trillion dollars if we saps fall for it !!!!!
Not that it looks like we will, these cold winters are having the desired effect.
No point except as part of a PR campaign. The evidence is that the medieval warming was as much as 2 degres warmer, to humanity's benefit & that the climate optimum pre 5,000 BC was perhaps as much as 4 degrees, with significant effects like the hippopotamii in the central Sahara. If 2 degrees is not harmful then the frame must be shifted to 4. In fact, since plants grow faster in high CO2 atmospheres, absorbing more CO2 there is a significant negative feedback which would probably prevent such a CO2 rise.
Why four degrees??
Because otherwise the Arctic Ice wouldn't melt, and the CAGW persons wouldn't know how to explain the snow we're having, that's why!
I heard a female say on the Beeb breakfast this morning (sorry, didn't get the name) that we're having this cold snap, and the previous cold winters because the ice is melting at the North Pole, thus the ocean is cold, thus we get snow.
You couldn't make it up ...
It si PR and that really is the point , itsa felt that 2 is not worrying enough so they make it 4. The fact that there no basis to believe that 4 is any more likely then 3.3 or 5.1 makes no difference its nice round number and double the last one.
[Re-posted from comments in Competing interests? thread:]
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Just so there's no confusion, the current average of HADCRUT3, GISTEMP, and the UAH vs RSS take on the satellite data gives a decadal trend of +0.15C (eg here: http://woodfortrees.org/plot/wti/mean:12/plot/wti/trend - see the Notes tab for detail).
Assuming a constant level of warming (which I don't), that gets us to +1.5C by 2100.
But according to the Gray article:
So the trend must increase immediately to 0.8C/decade (in other words more than a five-fold jump) and hold steady for the next 50 years.
Or it can rise at an increasingly steep rate, but unless it gets up close to 0.8C/decade fast it will have to accelerate at fantastic speed over the coming decades.
==================================
Even the worst-case IPCC A2 emissions scenario only gets us to ~+1.8C by 2060, rising to +3.6C by 2100.
This assumes a climate sensitivity of ~+3C per doubling of the atmospheric fraction of CO2 over the pre-industrial level.
The multi-model GCM ensembles project a lower bound of +0.2C/decade, and observations show ~+0.15/decade. The implication, at least to me, is that the models are demonstrating that the value for climate sensitivity is lower than assumed.
This is surely an unsound basis from which to be extrapolating a +4C rise by 2060 or 2100.
As the Bish said, to do so is suggestive of advocacy rather than scientific rigour. Even in the light of the dawning understanding by activists that 'our' emissions policies are going to fail in the face of emissions from the newly-industrialising economies of China, India and the rest.
The point of looking at it is to generate research funding and stay in a job where there is no requirement for rigorous thought or useable output. £60,000 does not sound excessive until you realise how utterly useless his work is.
You are missing the whole point. If you check any GCM output, you'll see that they mostly find a 2 degree per century trend in the beggining of the century, and when we reach the 2030s, the trend rises to 4/7ºK per century, due mostly to feedbacks.
To say that the current 2 degree celcius is almost falsified, therefore future trends of 4/7º are falsified is illogical on your part. For what is worth, they are not "concerned" about present trends, but mostly about future trends due to present "wrongdoings".
You'd have a better point naming out that there is no real evidence of how and why should these trends accelerate so much in the 21st century. Because there isn't any. Zero. Zilch. It's all guesswork.
Luis
If you are responding to me and not the headpost, please read the second half of my comment at 12:08PM above. As you can see, I am familiar enough with the spread of modelled projections to know that even A2 gets us nowhere near +4C by 2060.
I am also well versed in the debate over the assumption of net positive feedbacks and the inherently speculative nature of projecting a sharply rising trend later in the century.
I do appreciate your point, but not the rather dismissive way you made it.
The only positive feedback I know of is thata lot of melting ice slightly lowers the Earth's albedo. Does anybody know any other credibly supported ones?
The negative ones are that higher temperatures mean more water absorbed in air means more clouds & thus higher albedo worldwide. Also that more CO2 in the atmosphere means more plants cutting it.
The fact that the medieval, climate optimum & previous warmings going back for, at the very least, hundreds of millions of years, without positive feedback destroying the ecosphere very strongly suggest the net feedback is negative, I don't know of any evidence ever being produced to dispute this - simply ecofascist assertions.
Neil Craig
The major postulated positive feedback is from water vapour.
Higher ocean surface temperatures mean more evaporation. More water vapour in the air means more (and stronger) absorption and re-radiation of LW radiation - an enhanced greenhouse effect.
This amplifies the ~+1C forcing from increasing the atmospheric CO2 concentration to >550ppmv. More warming causes even more evaporation and bob's your death spiral.
Of course more water vapour in the atmosphere will likely mean more clouds (both positive and negative feedbacks from a radiative perspective) plus accelerated moist convective transport of energy up and out of the atmosphere (negative feedback).
Some claim that warming oceans and tundras will give up significant amounts of methane, itself a potent if short-lived greenhouse gas.
I find it telling that Prof. Anderson deals with the uncertainties in the way that he does (emphasis mine:
He appears to be saying that he already knows the results of the next few years of research and that strongly positive feedbacks are already pretty much settled science.
He will no doubt backtrack and rephrase if he sees this comment, but from my point of view he has made his position – and its bias – abundantly clear.
Thanks BBD. I had heard of water vapour effect & of the theoretical possibility of methane release but had forgotten them. I guers seven I have my subconscious biases that we must fight against..
I share your astonishment at the Professor's open certainty about the results of research not yet done- possibly he doesn't fight his bias very hard or possibly he knows exactly how most "research" in the field is done.
With few exceptions, for someone that doesn't often engage in blogs and then tries to do so openly to begin constructive debate, the level of childish competition and petty ridicule is pathetic. Fortunately there's a way out of it for me - I'll not open the site again - that way you can continue patting each other’s backs and congratulating yourselves on your individual and collective cleverness. And if you get pleasure from thinking you've annoyed me - good for you, but my skins much tougher than that and I receive much more detailed and thorough critiques from those I work with than is evident from the responses here. However, I did have the view that the dismissal of those sceptical of climate change was not generally helpful and that it was necessary for those of us who consider is an important issue to engage - but I can be insulted more substantively by folk I have much more respect for than those purporting to be interested in unveiling the truth behind the climate change here.
As a final comment illustrating the perfunctory nature of what appears here to pass for analysis:
Mac - read what i wrote - not just bits and pieces and then badly paraphrase. I'm not saying anything is dangerous or not in that paper - I'm just making a comment on other's definition of dangerous and a logical extension of that - so next time you read something you think you're going to disagree with, start with a deep breath, put your prejudice in a jar on the mantelpiece, sit down with a dram and read carefully. Then comment before retrieving your prejudice. Reply if you want, your mates here may read it and get a chuckle - and if that satisfies you fine - but you'll not be speaking to me - at least not on this blog (there must me more thorough an constructive sceptic blogs out there).
BBD and Craig - commenting on my comment: “I also think it is likely that higher temperatures will be discussed in the next few years. This is not, at least for most climate scientists, because we want more money, but that some of the issues we can't yet adequately quantify but know the sign off (i.e. make it warmer or cooler) will become more robustly quantified - and with few exceptions these make it warmer.”
Just read this carefully. If we are moderately confident of the sign of a large range of feedbacks and assuming we have the signs broadly right - it is not unreasonable to suggest that once quantified the emissions and hence the temperatures are 'likely' to be higher. How much depends on the relative size of the feedbacks - and yes, it is possible negative feedbacks could outweigh the larger number of positive feedbacks. But from our understanding of the feedbacks this looks unlikely - the methane emissions from tundra alone dwarf the short-term fertilisation etc. Ok, it could be if the quantity of ice melting is sufficient to 'release' sulphur and particularities from previously capped volcanic activity negative feedbacks may win out - but this looks unlikely to happen in the short term (100 yrs here) cos the bigger ice melts take longer - and anyway I get the impression that most of you think the ice won’t melt - so that feedback is kicked into touch anyway. Given I was trying to respond to a point rapidly to facilitate a useful dialogue I stand by what I wrote – if you think it illustrates an agenda to manipulate the science, I can tell you for certain you’re wrong – you may think that’s the case, but only I know – and unless you want to accuse me of lying then you’re simply wrong. And if you do accuse me of lying I’ll not care cos I’ll not know as I’ll not be checking this site again.
Related to the above – note Craig’s conversion of my “I also think it likely” into his “astonishment of the Professor's open certainty” – get a grip Craig, ‘likely’ and ‘certainty’ are not the same word – they don’t even look the same or have the same number of letters. Is this indicative of most of your statements posturing as argument? (Rhetorical cos I’ll not be checking).
Anyway enough of this. I’ll finish by saying I knew that most of those on this blog would disagree with my position. I tried to direct, honest and open – to respond quickly to encourage constructive dialogue about our disagreements. But in the end I am saddened by discovering that those amongst my colleagues who dismiss many sceptic blogs and bloggers as not interested in the subject, only their own egos, are broadly right – at least going by my brief experience with Bishops Hill. So have fun and enjoy each other – cos no one out here cares. If I can offer any advice (which I know will be ignored) it would be to keep a mirror next to you when next you contribute to a blog – they can be very revealing!
A very unimpressive performance on a public blog populated by an unselected group of internet browsers who may have no science education. It does little to counter the stereotypical view of social ineptitude and misguided arrogance amongst the climate science fraternity.
My response would be. Who are we meant to believe ? A super intelligent physicist like Freeman Dyson who has worked on climate models and has no financial interest in the matter or ....... you ?
"But from our understanding of the feedbacks this looks unlikely "
Not 10.234 or 10.985, but unlikely. Trillions of dollars in carbon trading loot for a guess !
Hi all – Been reading this blog for a while but first time posting.
Simple question for the Professor (although he’s now departed):
It is widely accepted that the previous interglacial peaked around two degrees warmer than the present interglacial.
At two degrees warmer there were not sufficient positive feedbacks to drive this up to 4 degrees warmer than the present.
How therefore does an increase in temperature of around one degree purely from a doubling of CO2 lead to a total increase of temperature of 4 degrees C when the feedback mechanisms to do this were not there in the previous interglacial?
@ Kevin Anderson in absentia
Good grief.
When I talk about uncertainty in the feedbacks I am referring to the big one – water vapour. Moist convective transport. Cloud formation or lack thereof at different heights and of different optical depths. Interaction with various species of anthropogenic aerosols.
You know perfectly well that massive uncertainty exists as to the net effect on T. You know that the net effects will change with change in global and regional T. Yet you simply re-iterate that we broadly know the sign of (some) feedbacks and that it is therefore safe to assert the amplification will be catastrophic and justifies extraordinary claims of +4K by 2060.
This argument is selective and incomplete and to my eye seeks to distract attention from its own weaknesses. Hence the detouring off into irrelevancies like deglaciation increasing sulphate aerosols from previously capped volcanoes.
Then this:
I am not accusing you of lying; I am accusing you of bias.
You go beyond what is justified by the state of knowledge and you do so because you believe you are right, not because you can prove that you are. Hence the partial aruguments, and, I suspect, some of the evident pique.
It is clear that you are an energy fantasist rather than an energy realist – which makes you very much the enemy in my book.
Furthermore, your on-record comments urging radical policy change in developed economies, including energy rationing, are naïve beyond belief.
Let’s not forget that the hideous impasse in climate and energy policy was in large part created by scientific activism and its hyper-focus on CO2. Yes, the UN FCCC is heavily responsible for this. No it did not achieve it on its own. It required a large number of people like yourself to help.
Such scientific advocacy – both overt and especially the covert -has done more harm than good in the matter of climate change. It continues to be the biggest single obstacle to formulating any kind of effective climate or energy policy
Thanks for your contribution.
Well there goes the possibilty that alarmists wanted "dialogue". Though the professor has emphasised his use, at the other end of the paragraph, of the word "likely" he has given us no actual evidence of whyit should be & decklined to address the fact that history shows that the alleged positive feedbacks don't happen. That is measured evidence & trumps any theory,, particularly the sort of unspecific ones he produced. I know that much science but then I ain't a professor.
@Kevin Anderson
You engage, when detractors highlight issues with your POV, you declare a foul, and run away.
"but my skins much tougher than that"
And there you go throwing your toys out the pram, clearly, as exampled by your post here and your published comments, you see what you want to see, and ignore anything counter to your views as if it didn't exist, or call foul on the presentation avoiding the points made.
I would call this approach blinkered, some call it bias, but that is the only impression you leave us with.
"the level of childish competition and petty ridicule is pathetic."
Indeed!
"it would be to keep a mirror next to you when next you contribute to a blog"
I suggest you take some of your own advice Sir.