A study from the University of Exeter on species decline declares “climate change warnings not exaggerated.”
However the press release leaves one singularly unimpressed with the raw activism of the lead researcher, who says: “It is time to stop using the uncertainties as an excuse for not acting. We need to act now to prevent threatened species from becoming extinct. This means cutting carbon emissions.”
The paper is in press, but it mentions “existing responses to climate change.”
Decreased ice cover in the Bering Sea reduced the abundance of bivalve molluscs from about 12 to three per square metre over a very short period of time (1999-2001). These shells are the main food source for species higher up the food chain, such as Spectacled Eider.
Arctic sea ice cover is mostly a function of the winds. It’s a shame the molluscs have declined, but it was not caused by global warming, anthropogenic or not.
Climatic warming and droughts are causing severe declines in once-common amphibian species native to Yellowstone National Park in the United States of America. Between 1992-1993 and 2006-2008, the number of blotched tiger salamander populations fell by nearly half, the number of spotted frog populations by 68 per cent, and the number of chorus frog populations by 75 per cent.
So the recent amphibian virus infections widespread through North America have nothing to do with these reductions?
In Antarctica, few animals exist on land, but one of the most abundant, a nematode worm living in the soil in dry, cold valleys experienced a 65 per cent decline between 1993 and 2005 as a result of climate change.
First, so what? Second, there’s no evidence of warming temperatures in Antarctica except Steig’s deprecated paper using the peninsula data “smeared” over the rest of the continent. Quite naughty. Third, there are few scientists even in the dry valleys; I demand a recount.
Next, we’re treated to examples of “predicted responses” to climate change. How insulting is this? “We found some guys who made these forecasts. Be afraid, they could happen.”
This is not science!
On Tenerife, an endemic plant, the Caňadas rockrose has a 74 to 83 per cent chance of going extinct in the next 100 years as a result of climate change related droughts. [Who “calculates” these odds?]
In Madagascar, climate warming is predicted to cause endemic reptiles and amphibians, often found in mountain ranges, to retreat towards the summit of the mounts. With a warming of just two degrees Celsius, well within current projections, three species are predicted to lose all of their habitat.
Birds living in northern Boreal Forests in Europe are expected to decline as a result of global warming. Species such as Dotterel are predicted to decline by 97 per cent by 2100 and species such as Two-barred Crossbill and Pine Grosbeak could lose their entire range within Fenno-Scandia.
Gosh.
Views: 116
More research needed. Send more funding. And a bigger computer.
…. Gosh indeed. Scream loud enough and long enough “The End is Nigh” and someone, somewhere will pay you money, if not just for the entertainment value alone.
Actually, your last point RT causes me to rephrase – they are actually shouting “The End might be Nigh – about a 74 to 87 percent chance…. for a plant on some island somewhere… we think… perhaps. (mumble)…. (shuffle)… could I have that grant now?”
As for the molluscs in the Bering Sea… Now, I’m not a commercial fisherman or marine biologist so I wouldn’t know, but I am a sceptic when I hear that changing ice cover caused the bivalve mollusc population to crash to just 25% in 2 years. To me, that is saying A happened and B happened, therefore A caused B.
I am reminded of Richard Lindzen’s famous dirt-kicking analogy:
Is there a boilerplate programme for this sort of nonsense, possibly filed in university libraries?
It ticks all the boxes for environmental advocacy, not science.
The certainties we see reported – and taken as true certainties, that of an action happening – are the certainties of the outcome of model runs, as far as I can see. Given specific assumptions, the climate models give a specific range of outcomes, regardless who runs the models. This appears to be the basis for warmists such as the fellow here. They mistake certainty of actual outcome with certainty of model results.
I suppose the warmists can be forgiven this error, for they are told the science is “settled”. If so, then the model runs are not based on assumptions-in-dispute, but truths. Perhaps that is the reason some can say that “observations are not very useful” as they promote computer models. Observations contain error and natural variability, while computer models deal with the essential elements only, and to great precision (precision vs accuracy, note).
The nature of nature is now like the words of the Koran, the specific words of God not subject to interpretation, modification or dispute. The arbiter of truth has spoken; nothing is left to do but obey. This essential base for the warmists – skeptics would call it an assumption – is the point of divergence of all CAGW debate. As any point can be questioned in theory, but for the believers of, for example the Koran or the Bible, makes no sense as an absolute is said to be a non-absolute, what skeptics see as a disconnect in a chain of logic is to a warmist a smooth movement from known to known.
The Suzuki-Gore followers are just like the Exeter writers. Models ARE reality, and in fact describe it better than observation. Cognitive dissonance, wilful blindness and esteem for the morally righteous authority: how far have we come since a note on a map that said, “Here Be Monsters”, stopped travel to far-off lands?
I think these assumptions, that Doug correctly points out are set in stone for the warmists, are what are referred to as strong priors in Bayesian probability theory that often gets bandied around in these discussions.
This is often used in a subjective sense, rather than a purely objective hard-science sense. You have to watch for this.
http://en.wikipedia.org/wiki/Strong_prior
From here:
http://en.wikipedia.org/wiki/Prior_probability
A prior is often the purely subjective assessment of an experienced expert.
My point being that you often need to tease out these weasel words which sound impressive to the layman, but in reality mean:
“Trust us, we are experts. All these scenarios are based on our collective wisdom, and very little else”
Doug, Andy, What assumptions do you consider to be in dispute?
The assumption that the net effect of water vapour feedback on the climate system is positive, leading to high climate sensitivity, is one thing I would consider “in dispute”, given that there is no empirical evidence to support this.
However, my general observation is that a lot of assumptions are made on the basis that the underlying models of climate are correct.
This caveat is never, or rarely, explained. It is taken as a given, which it is clearly not.
On this very topic (of climate sensitivity), there is a recent article by Roy Spencer
http://www.drroyspencer.com/2010/05/strong-negative-feedback-from-the-latest-ceres-radiation-budget-measurements-over-the-global-oceans/
Andy, the most recent peer reviewed evidence is that water vapor is a positive feedback. Chang and Coakley (2007), Eitzen et al. (2008), Clement (2009) and Dessler (2010). So I would not say that water vapor is assumed to be positive but rather that it has been observed and measured to be positive.
As for Roy Spenser’s blog post on climate sensitivity it will be more convincing when it has been published in the peer review literature, (if this has already happened I would enjoy reading it, please link).
I don’t have a link to a peer-reviewed version of Spencer’s article, but Lindzen and Choi 2011 is a paper suggesting low sensitivity.
Real world observations are tracking below the lowest IPCC projection.
Nick, to say that “positive feedback has been observed and therefore climate sensitivity is high” seems a little simplistic for my liking.
There may well be positive feedbacks in the climate system, but we also observe negative feedbacks. Clouds are an obvious example of this.
The key thing is, what is the net feedback, and what do real-world observations tell us?
The IPCC’s models assume high sensitivity and adjust them using aerosol fudge-factors to fit the real-world observations. At least, this is the message that Richard Lindzen has been telling us for a while.
The real world tells us that the total warming for the last 150 years is around 0.8 degC max.
If we are going to get these thermageddon scenarios then the temps have a lot of catching up to do.
Sorry Andy I want to stay on track with the question of what assumptions in the models you think are questionable. Since the models generally calculate climate sensitivity (from observations, measurements and fundamental assumptions no doubt) I would rather discuss the issue of total sensitivity another time (although I can think of some interesting points for debate if you can be patient). Thanks
Andy, do you have any opinion on Kaufman et al. 2011? I find the theory that increased particulate emissions from China over the last decade have (temporarily) masked AGW very compelling. I’m guessing that you (or someone here) will dismiss this but I would like to understand your reasoning.
My understanding is that many people who dispute AGW do so on the basis of insignificant warming over the last few years. This paper explains that fairly well (seems to at least) so I would appreciate your take on it.
Cheers
Kaufmann paper addressed here:-
https://www.climateconversation.org.nz/open-threads/climate/global-warming-general-001/#comment-62166
Nick, Eitzen, Clement and Dessler were looking at clouds (liquid) – not water vapour (gas). See:-
http://www.weatherquestions.com/What_is_water_vapor.htm
WV is falling in the GHG critical pressure zones contrary to AGW but consistent with Miskolczi. See: Solomon et al (2010), Paltridge et al (2009) and Pierce et al (2006). WV plots here:-
http://climate4you.com/ (click “Greenhouse Gasses”)
Assuming that you meant clouds, the feedback has certainly NOT “been observed and measured to be positive”. Just read the papers that you cite. Eitzen and Xu, a modeling exercise, doesn’t nor do they find a net positive effect in the modeling. Table 6 shows a net NEGATIVE CRF. This is consistent with other SP-GCM studies e.g. Bretherton 06 and Wyant 06.
Clement, Bergman and Norris is speculative (“appeared to be linked”), regionally specific (more work needed) and runs into the Aarhus and CERN CLOUD experiments.
Dessler ran into instant rebuttal:-
The Dessler Cloud Feedback Paper in Science: A Step Backward for Climate Research
http://wattsupwiththat.com/2010/12/09/the-dessler-cloud-feedback-paper-in-science-a-step-backward-for-climate-research/
I haven’t got the time for Chang and Coakley right now but maybe Sunday.
Re this: “As for Roy Spenser’s blog post on climate sensitivity it will be more convincing when it has been published in the peer review literature, (if this has already happened I would enjoy reading it, please link).”
See Spencer – Braswell (2010) ‘On the diagnosis of radiative feedback in the presence of unknown radiative forcing’
http://www.drroyspencer.com/wp-content/uploads/Spencer-Braswell-JGR-2010.pdf
[19] We find that considerable physical insight into the covariations between radiative flux and temperature can be gained through phase space plotting of the data. Using the 1 month comparisons between CERES radiative fluxes and TMT in Figure 1a as an example, if we connect the data points in time sequence (Figure 3a), we can visualize the time evolution or “trajectory” of the system. In this case, we see evidence of linear striations having a steeper slope than a linear regression fit using all of the data together. Those striations are approximately parallel to the dashed line, which is drawn to have a slope of 6.2 W m−2 K−1.
And,
[60] Striations in 9 years of global average CERES radiative fluxes from the Terra satellite have a slope around 6 W m−2 K−1 in net (LW + SW) radiative flux variability. This is similar to the feedbacks diagnosed by Lindzen and Choi [2009] from interannual variability in recently recalibrated Earth Radiation Budget Satellite data, as well as that diagnosed for a composite of 15 strong tropical intraseasonal oscillations analyzed by Spencer et al. [2007].
The “6.2 W m−2 K−1” found in SB10 and LC09 (confirmed LC11) is a strongly negative feedback.
Richard C, I take your point about clouds being liquid. I had not made that connection thanks for clarifying my understanding. However if we discount clouds from the equation then I don’t think there is any question that the feedback of water vapor is positive, as far as I know water vapor is unquestionably the strongest greenhouse gas, whichever side of the debate you stand on. Feel free to correct my understanding however.
Clouds have been more controversial and I have provided several peer reviewed papers that show that the feedback is positive. As you rightly point out none of them are 100% convincing on their own and they all use different methods but taken together they make a reasonable case (I think).
The single peer reviewed paper from 2006 that you present which deals explicitly with clouds is less convincing as a body of evidence (Wyant & Bretherton is one paper unless I’m mistaken).
As far as I know, most of the GCMs don’t model clouds (Richard C?)
This seems to be a fairly major oversight, as intuitively we know that clouds have a huge effect on air temperature.
Conventional GCMs do model clouds albeit statically at a coarse resolution and without low cloud detail. These include all AR4 simulations and they return a positive feedback.
Superparameterized (SP) GCMs use a dynamic cloud resolving module (CRM). These newer configurations return a negative feedback. AR4 knew about this because it had been reported in 2006 but they gave it a solid ignoring.
The problem now is to get finer resolution for low cloud but the computing requirements are massive and there’s nothing that will handle it.
Nick, my reply here, this threads too skinny:-
https://www.climateconversation.org.nz/2011/07/species-decline-or-scaremongering/#comment-62910
Nicely explained, Doug, thank you.
A few weeks ago Willis Eischenbach posted an excellent article titled ‘Turtles All The Way Down’ to explain (and eviscerate) the quaint belief in untested and untestable models that is so widespread in Climate Science. The title comes from a very brief story about a village wise man who was asked by an elderly woman “What holds up the turtle our world is balancing on?” The answer was “It’s turtles all the way down, madame!”
When one replaces ‘turtles’ with ‘models’, some idea of the fatuity of the Warmist doctrine is exposed for what it is – models all the way down!
“… on average the declines that have already happened match predictions in terms of the relative risk to different species”.
This is put forward as evidence that the countless predictions must be taken seriously. Because the current models are accurate with 20:20 hindsight so, therefore, the fortune-tellers are likely to be right in future.
But who would publish a model/paper with results that have already been proven wrong? The models are tweaked and curve-fitted to match any known (past) data. It would be stupid to omit this step. But that now tweaked model is the same wrongly programmed matrix it was before, except with some manually-entered data. It is probably probably less capable than ever of foretelling the future.
OT but check out this sensationalist headline from the Dom-Post this morning.
http://www.stuff.co.nz/environment/5287638/Climate-change-evidence-undeniable
Kevin Trenberth leads the charge of the ‘Flight Brigade.’
Once again alarmists get the headlines based on mis-truths touted as facts.
Cheers
Coops
Disastrous floods, heatwaves, storms and droughts are becoming more frequent because of climate change, and will continue to do so.
Ok, so there’s no distinction between natural climate change and human induced.
So we could summarise this thus:
climatic changes are being seen because the climate is changing.
This is a problem with the media. They associate all climate change with human caused climate change
Even the IPCC and the UNFCCC can’t agree on a definition of “climate change”
Coops, Trenberth is one of those Kiwis who makes the rest of us Kiwis collectively look like utter prats on the world stage. All of his alarmism has little to do with actual science as we know it.
Check out the current threads on Bishop Hill and Climate Audit – the cover-up post Climategate is just starting to unravel in spectacular fashion. Fascinating stuff!
On the subject of scaremongering, I found this great comment on Bishop Hill which I will cut and paste here.
It shows a timeline of scaremongering on climate over the last century:
————————————————————————————–
A reminder about all the climate scares in the past 114 years
Climate Change Timeline – 1895-2009
NEW: 5th Year of Global Cooling, NOAA Says <- Read!
There is most certainly a pattern to climate change…
…but it’s not what you may think:
For at least 114 years, climate “scientists” have been claiming that the climate was going to kill us…but they have kept switching whether it was a coming ice age, or global warming.
33diggsdigg
• 1895 – Geologists Think the World May Be Frozen Up Again – New York Times, February 1895
• 1902 – “Disappearing Glaciers…deteriorating slowly, with a persistency that means their final annihilation…scientific fact…surely disappearing.” – Los Angeles Times
• 1912 – Prof. Schmidt Warns Us of an Encroaching Ice Age – New York Times, October 1912
• 1923 – “Scientist says Arctic ice will wipe out Canada” – Professor Gregory of Yale University, American representative to the Pan-Pacific Science Congress, – Chicago Tribune
• 1923 – “The discoveries of changes in the sun’s heat and the southward advance of glaciers in recent years have given rise to conjectures of the possible advent of a new ice age” – Washington Post
• 1924 – MacMillan Reports Signs of New Ice Age – New York Times, Sept 18, 1924
• 1929 – “Most geologists think the world is growing warmer, and that it will continue to get warmer” – Los Angeles Times, in Is another ice age coming?
• 1932 – “If these things be true, it is evident, therefore that we must be just teetering on an ice age” – The Atlantic magazine, This Cold, Cold World
• 1933 – America in Longest Warm Spell Since 1776; Temperature Line Records a 25-Year Rise – New York Times, March 27th, 1933
• 1933 – “…wide-spread and persistent tendency toward warmer weather…Is our climate changing?” – Federal Weather Bureau “Monthly Weather Review.”
• 1938 – Global warming, caused by man heating the planet with carbon dioxide, “is likely to prove beneficial to mankind in several ways, besides the provision of heat and power.”– Quarterly Journal of the Royal Meteorological Society
• 1938 – “Experts puzzle over 20 year mercury rise…Chicago is in the front rank of thousands of cities thuout the world which have been affected by a mysterious trend toward warmer climate in the last two decades” – Chicago Tribune
• 1939 – “Gaffers who claim that winters were harder when they were boys are quite right… weather men have no doubt that the world at least for the time being is growing warmer” – Washington Post
• 1952 – “…we have learned that the world has been getting warmer in the last half century” – New York Times, August 10th, 1962
• 1954 – “…winters are getting milder, summers drier. Glaciers are receding, deserts growing” – U.S. News and World Report
• 1954 – Climate – the Heat May Be Off – Fortune Magazine
• 1959 – “Arctic Findings in Particular Support Theory of Rising Global Temperatures” – New York Times
• 1969 – “…the Arctic pack ice is thinning and that the ocean at the North Pole may become an open sea within a decade or two” – New York Times, February 20th, 1969
• 1969 – “If I were a gambler, I would take even money that England will not exist in the year 2000″ — Paul Ehrlich (while he now predicts doom from global warming, this quote only gets honorable mention, as he was talking about his crazy fear of overpopulation)
• 1970 – “…get a good grip on your long johns, cold weather haters – the worst may be yet to come…there’s no relief in sight” – Washington Post
• 1974 – Global cooling for the past forty years – Time Magazine
• 1974 – “Climatological Cassandras are becoming increasingly apprehensive, for the weather aberrations they are studying may be the harbinger of another ice age” – Washington Post
• 1974 – “As for the present cooling trend a number of leading climatologists have concluded that it is very bad news indeed” – Fortune magazine, who won a Science Writing Award from the American Institute of Physics for its analysis of the danger
• 1974 – “…the facts of the present climate change are such that the most optimistic experts would assign near certainty to major crop failure…mass deaths by starvation, and probably anarchy and violence” – New York Times
Cassandras are becoming
increasingly apprehensive,
for the weather
aberrations they are
studying may be the
harbinger of another
ice age
• 1975 – Scientists Ponder Why World’s Climate is Changing; A Major Cooling Widely Considered to Be Inevitable – New York Times, May 21st, 1975
• 1975 – “The threat of a new ice age must now stand alongside nuclear war as a likely source of wholesale death and misery for mankind” Nigel Calder, editor, New Scientist magazine, in an article in International Wildlife Magazine
• 1976 – “Even U.S. farms may be hit by cooling trend” – U.S. News and World Report
• 1981 – Global Warming – “of an almost unprecedented magnitude” – New York Times
• 1988 – I would like to draw three main conclusions. Number one, the earth is warmer in 1988 than at any time in the history of instrumental measurements. Number two, the global warming is now large enough that we can ascribe with a high degree of confidence a cause and effect relationship to the greenhouse effect. And number three, our computer climate simulations indicate that thegreenhouse effect is already large enough to begin to effect the probability of extreme events such as summer heat waves. – Jim Hansen, June 1988 testimony before Congress, see His later quote and His superior’s objection for context
• 1989 -”On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but – which means that we must include all doubts, the caveats, the ifs, ands and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climate change. To do that we need to get some broad based support, to capture the public’s imagination. That, of course, means getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This “double ethical bind” we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.” – Stephen Schneider, lead author of the Intergovernmental Panel on Climate Change, Discover magazine, October 1989
• 1990 – “We’ve got to ride the global warming issue. Even if the theory of global warming is wrong, we will be doing the right thing – in terms of economic policy and environmental policy” – Senator Timothy Wirth
• 1993 – “Global climate change may alter temperature and rainfall patterns, many scientists fear, with uncertain consequences for agriculture.” – U.S. News and World Report
• 1998 – No matter if the science [of global warming] is all phony . . . climate change [provides] the greatest opportunity to bring about justice and equality in the world.” —Christine Stewart, Canadian Minister of the Environment, Calgary Herald, 1998
• 2001 – “Scientists no longer doubt that global warming is happening, and almost nobody questions the fact that humans are at least partly responsible.” – Time Magazine, Monday, Apr. 09, 2001
• 2003 – Emphasis on extreme scenarios may have been appropriate at one time, when the public and decision-makers were relatively unaware of the global warming issue, and energy sources such as “synfuels,” shale oil and tar sands were receiving strong consideration” – Jim Hansen, NASA Global Warming activist, Can we defuse The Global Warming Time Bomb?, 2003
• 2006 – “I believe it is appropriate to have an over-representation of factual presentations on how dangerous it is, as a predicate for opening up the audience to listen to what the solutions are, and how hopeful it is that we are going to solve this crisis.” — Al Gore, Grist magazine, May 2006
• Now: The global mean temperature has fallen for four years in a row, which is why you stopped hearing details about the actual global temperature, even while they carry on about taxing you to deal with it…how long before they start predicting an ice age?
The actual Global Warming Advocates' chart, overlayed on the "climate change" hysterics of the past 120 years. Not only is it clear that they take any change and claim it's going to go on forever and kill everyone, but notice that they even sometimes get the short-term trend wrong…
Worse still, notice that in 1933 they claim global warming has been going on for 25 years…the entire 25 years they were saying we were entering an ice age. And in 1974, they say there has been global cooling for 40 years…the entire time of which they’d been claiming the earth was getting hotter! Of course NOW they are talking about the earth “warming for the past century”, again ignoring that they spent much of that century claiming we were entering an ice age.
The fact is that the mean temperature of the planet is, and should be, always wavering up or down, a bit, because this is a natural world, not a climate-controlled office. So there will always be some silly bureaucrat, in his air-conditioned ivory tower, who looks at which way it’s going right now, draws up a chart as if this is permanant, realizes how much fear can increase his funding, and proclaims doom for all of humanity.
• 2006 – “It is not a debate over whether the earth has been warming over the past century. The earth is always warming or cooling, at least a few tenths of a degree…” — Richard S. Lindzen, the Alfred P. Sloan professor of meteorology at MIT
• 2006 – “What we have fundamentally forgotten is simple primary school science. Climate always changes. It is always…warming or cooling, it’s never stable. And if it were stable, it would actually be interesting scientifically because it would be the first time for four and a half billion years.” —Philip Stott, emeritus professor of bio-geography at the University of London
• 2006 – “Since 1895, the media has alternated between global cooling and warming scares during four separate and sometimes overlapping time periods. From 1895 until the 1930′s the media peddled a coming ice age. From the late 1920′s until the 1960′s they warned of global warming. From the 1950′s until the 1970′s they warned us again of a coming ice age. This makes modern global warming the fourth estate’s fourth attempt to promote opposing climate change fears during the last 100 years.” – Senator James Inhofe, Monday, September 25, 2006
• 2007- “I gave a talk recently (on fallacies of global warming) and three members of the Canadian government, the environmental cabinet, came up afterwards and said, ‘We agree with you, but it’s not worth our jobs to say anything.’ So what’s being created is a huge industry with billions of dollars of government money and people’s jobs dependent on it.” – Dr. Tim Ball, Coast-to-Coast, Feb 6, 2007
• 2008 – “Hansen was never muzzled even though he violated NASA’s official agency position on climate forecasting (i.e., we did not know enough to forecast climate change or mankind’s effect on it). Hansen thus embarrassed NASA by coming out with his claims of global warming in 1988 in his testimony before Congress” – Dr. John S. Theon, retired Chief of the Climate Processes Research Program at NASA, see above for Hansen quotes
Next time you see the usual "global warming" chart, look carefully: it is in tiny fractions of one degree. The ENTIRE global warming is less than six tenths of one degree. Here is the Global Warming Advocates' own chart, rendered in actual degrees like sane people use. I was going to use 0-100 like a thermometer, but you end up with almost a flat line, so I HELPED the Climate Change side by making the temperature range much narrower, and the chart needlessly tall to stretch the up-down differences in the line.
End of the list.
In c100 years from now, the population of Earth are going to be asking themselves what the hell was going on back in the 20th/21st century!!
"Were they all mad?" will be one of the questions. What kind of voodoo science were they adhering to? will be another.
Nick, you’re getting to the core tenet of AGW here:-
The mere presence of WV does not make it a feedback or forcing, positive or negative, it’s the incremental change that does. AGW hangs on the thread of amplified WV levels in the GHG critical pressure zones in the upper troposphere (300 hPa, 400 hPa) after which heat is free to dissipate to space. However, AGW falls flat on it’s face at the first hurdle because WV levels are falling there and immediately above and below. See: Vonder Haar et al (2005), Solomon et al (2010), Paltridge et al (2009) or see for yourself
It gets worse because as Miskolczi found: “the total effective amount of greenhouse gasses in the atmosphere has not significantly increased over the last 60 years” i.e. it doesn’t matter how much CO2 is pumped into the atmosphere (levels have been much higher in the past BTW) because the hydrological cycle compensates.
You cite a paper that finds net negative cloud radiative forcing (CRF) and you think that’s a “reasonable case” for positive cloud feedback? More thinking required don’t you think?
Meanwhile, Spencer and Braswell’s rebuttal to Dessler 2010 has been accepted for publication:-
http://www.drroyspencer.com/2011/07/our-refutation-of-dessler-2010-is-accepted-for-publication/
As far as I’ve checked you’ve cobbled together a highly speculative paper that has been gazumped by recent science, one you’ve misunderstood completely and a rebutted paper (plus one other). Your case wouldn’t make it past a preliminary hearing before a judicial officer.
You’re very much mistaken and this is a huge body of evidence. Bretherton 06 is a report:-
“The Climate Process Team on Low-Latitude Cloud Feedbacks on Climate Sensitivity”
By Christopher S. Bretherton 2006
Studiously ignored by IPCC AR4 2007
Wyant06 is a GRL paper:-
“Climate sensitivity and cloud response of a GCM with a superparameterization”
Matthew C. Wyant,1 Marat Khairoutdinov,2 and Christopher S. Bretherton1
Received 12 December 2005; revised 14 February 2006; accepted 17 February 2006; published 29 March 2006.
ftp://128.95.176.42/pub/breth/papers/2006/SPGRL.pdf
The Eitzen and Xu 2008 paper that you cite, corroborates this finding.
Richard C, You are absolutely correct WV acting as a positive feedback is a fundamental part of my belief in dangerous global warming so I will have a look at the links you provide with interest.
As an aside however how do you reconcile the fact that climate has been highly variable in the past but that all the feed back are negative? Am I misrepresenting your position or do you believe is there an extremely powerful (and undetected) forcing that overcomes all this negative feedback?
Nick,
I think that the simple answer to the question “what caused the previous climatic events” is – we don’t know
Nir Shaviv, for example, has postulated that the ice ages were caused by the passages through the Milky Way spiral arms.
Svenmark’s theories on cosmic ray flux also provide another external forcing. The CERN experiments being undertaken at the moment will hopefully shed some light on this.
I’m not trying to answer on behalf of Richard C, but that’s not how feedbacks work. The “forcing” acts, and the feedback attenuates (negative) or accentuates (positive) the forcing. Almost all feedbacks in nature are negative, otherwise a small forcing will cause a runaway situation. If a positive feedback exists (eg nuclear detonation) it plays itself out quickly as it expends its potential energy.
I understand what you’re saying, that previous forcings must have been very large then if they were attenuated and still had the effects they did.
But bear in mind that you are used to discussions around GHG forcings (eg: 2-3 W/m2), which are very small. A change in (for example) TSI at around 1360 W/m2 can have a very large effect on the climate, and there will be few feedbacks to temper it (less energy entering the system will cause rapid cooling, and it’s difficult to imagine a feedback that will stop this occurring quickly).
The same is true for cloudiness. More cloud (even a few percent) will dominate climate systems for a while, simply because the effect is similar to a reduction in TSI – less energy reaches the oceans because more SW radiation is reflected away. In this case however the increased cloudiness may attenuate the forcing slightly (negative feedback) by slowing some radiative heat loss going back out, but considering that less energy was received in the first place this effect will presumably be minor.
Bob, just to be clear are you saying that positive feedback in our planets climate cannot exist because it would result in runaway warming?
A positive feedback (as I understand the term when used by climate scientists) is a force multiplier. So some initial warming increase causes a water vapour increase, which blocks LW radiation and causes more warming. This extra warming in turn causes more water vapour which causes more warming, which causes more water vapour which causes more warming, etc. In a closed system one would eventually expect a steady state position to result (at a higher temperature), since each increment is increasingly smaller than the preceding one (assuming the feedback value < 1 of course). In an open system, such as our planet, the incoming energy continues to build unabated, and as a result there is theoretically no end to the warming. Hansen believes this is what happened on Venus (he's actually an astrophysicist I believe) until all the Venusian oceans evaporated away.
See:
Kasting J.F. (1988). "Runaway and moist greenhouse atmospheres and the evolution of earth and Venus". Icarus 74 (3): 472–494.
http://www.sciencedirect.com/science/article/pii/0019103588901169
Now in theory any warming forcing would have the same effect. It is therefore a valid question to ask why this cycle has not happened in the past on Earth when temperatures were much warmer.
Why in an open system does incoming energy continue to build unabated? This is the exact opposite to what I would expect.
According to GHG theory, it can’t escape. There is nothing in the warmer environment stopping the SW solar energy from coming in to the oceans – ie: no negative feedback. It just can’t get out again. So the warming continues, and drives further evaporation, water vapour etc. The characteriestic emission level increases further and further, and because of the lapse rate, surface warming builds up, while generating more water vapour. All the while (every day) more SW energy is coming in.
If you can’t get rid of the energy, it has to go into the system. If, by going into the system, it reduces further the ability of the system to get rid of its energy, any further energy added to the system will repeat the loop.
In the case of Venus, what apparently stopped the process was the loss to space of the water vapour. The remaining CO2 doesn’t of course have positive feedback on its own, hence the stable, albeit very high, temperatures.
By the way, I’m not saying I believe this, it’s just that it’s the argument as I understand it.
There are two things, as I understand it, that modify this situation a bit. The first is that as the ocean temperature rises, it radiates energy away at a faster rate (4th power). However, it makes no real difference, as this radiation is blocked just the same as the previous radiaiton. Technically, one expects the wavelength to change due to the higher temperature, but I don’t think this makes any difference in reality (I haven’t checked).
The second is of course convection. This is the main flaw in the logic, since most GHG arguments seem to focus just on radiation. Of course convection (or advection I suppose) allows the water to gather heat at the ocean surface via evaporation (a very powerful heat ‘absorber’, if you like) and transport it high up into the atmosphere where it loses it again and falls back to the ocean. This ‘lost’ heat is then easily able to radiate away from this higher altitude. Effectively the heat has by-passed most of the opaque atmosphere. The higher the surface temperature becomes, the more this process transports heat. Energy will always find the easiest path.
The good news is that this appears to be the reality of the situation. There appears to be a net negative feedback process occurring to reduce the forcing as warming occurs, or an efficient heat transport process is operating (or of course a mixture of the two). Over the past decade direct solar forcing has been fairly steady, and GHG forcing has been high, yet there has been no accumulation of heat in the oceans. This has been acknowledged in the peer-reviewed literature.
Does Hansen believe the same could happen on Earth as happened on Venus (according to him)?
Bob, I think you misrepresent GHG theory when you say (energy) can’t escape from the system. No GHG models show runaway heating due to small increases in temperature. Rather an amplified increase that levels off as a new equilibrium is found between retained heat and heat being radiated into space (at the 4th power as you say).
I make this point because the idea that positive feedback will result in run away warming is not correct.
If your hypothesis that advection (new concept for me thanks!) is preventing the recent warming wouldn’t we expect to see the radiative imbalance between incoming and out going radiation disappear?
Bingo! Collect your prize, finally someone from the other side gets it.
For confirmation, see here:
http://www.pas.rochester.edu/~douglass/papers/KD_InPress_final.pdf
By radiative imbalance I refer to the difference between incoming and outgoing energy. Trenberth et al. (2009) uses measurements from space to determine that the imbalance to be 0.9W/m^2 +/- 0.5
Excellent answer. By Trenberth et al. (2009), I presume you mean this paper?
http://content.imamu.edu.sa/Scholars/it/net/trenbert.pdf
(It of course references Fasullo & Trenberth (2008a), but the content is the same.)
If so, the stated imbalance is in fact 0.85 ± 0.15 W m−2 at TOA, but you’re close enough.
However, there’s a small detail that almost everyone overlooks. Note the following:
Changes things a bit, doesn’t it? I bet up to now you thought they had actually measured that pesky imbalance. Not a sausage, it comes from Hansen (2005), from a model.
The measured CERES imbalance of 6.4W/m2 was clearly wrong, so they imposed their own modelled number, and proceeded as if it was the measured value. Is it any wonder the ‘measured’ value exactly matches the theoretical value?
Would you like to go further down the rabbit hole? I have more.
“I have more”.
KD10?
“The measured CERES imbalance of 6.4W/m2 was clearly wrong”
And by extension, the same 6.2 W m−2 K−1 found in SB10 (using CERES) and LC09/11 were wrong too?
It is the same flux isn’t it?
Oops, wires crossed. the “6” is coincidence. It’s the feedback parameter in SB10 and LC09/11 – not imbalance.
I see SB11 has net radiative flux (Fig 2) shown as an anomaly fluctuating approx +1 to -1 about zero. The T&F net flux should have been something like that?
And now that I have your attention, let me ask you just one question (this is very important, it’s at the heart of everything):
From where exactly do we get the radiation imbalance, and what is its magnitude?
I didn’t mean energy can’t escape, I meant the earth can’t get rid of the excess (imbalance) energy before more energy pours in from the sun. My apologies for the poor wording.
The excess heat is supposed to stay in the oceans, warming them.
Yes, at some point a new equilibrium will theoretically be reached, unless the feedback is > 1.
Hmm, I wonder where Nick’s disappeared to. Perhaps he decided he preferred the blue pill.
Are you able to estimate the magnitude of your unknown forcing required to account for past variability given a zero or negative feedback effect?
How do you account for the scale of the global temperature response to know forgings such as solar cycles and volcanic eruptions?
Nick, You appear to be asking questions that not even climate researchers know the answer to
Well most climate researchers subscribe to CO2 induced global warming theory and have very good estimates for the magnitude of forcings, what causes them and why temperatures reacted the way they did historically.
The general hypothesis of skeptics seems to be more along the lines of climate variability (of unknown magnitude) is caused by (unknown) natural effects of (unknown) magnitude great enough to overcome negative feedback (also of unknown magnitude). I don’t think it is unreasonable for me to ask you to fill in the blanks a little
So you subscribe to the view that all past climatic events were driven by CO2?
No, only the current warming. The same view as held by the majority of climate scientists
I think it is an incorrect assertion that a sceptic of the CAGW theory needs to find an alternative hypothesis.
The theory can be falsified using empirical observations without finding another theory, much in the way that I could find someone not guilty of a murder whilst the actual murderer gets away.
But Andy your various arguments against CAGW (It’s natural, it’s GCR climate sensitivity is low, it’s the milky way) are alternative hypothesis . I’m not asking you to present a hypothesis I’m asking you to demonstrate that the hypothesis you have already presented is internally consistent.
I thought that Bob D and Richard C had already presented this case.
Are you expecting me to present my own case?
This is starting to feel like a cross-examination in a court.
Well done Nick, you have them on the run!
I haven”t presented an hypothesis. You have created a strawman.
We are proposing that the CAGW hypothesis is internally inconsistent, not that we have an alternative hypothesis.
Science advances by creating falsifiable theories. If a theory is falsified, then we look for another theory.
If the IPCC claim that most of the 20th Century warming was likely caused by human generated CO2 emissions, then how come it has stopped for 10+ years and we can find no trace of the “missing heat”?
I have to admit I am a bit of a Karl Popper aficionado, having read his stuff decades ago
Conjectures and Refutations: The Growth of Scientific Knowledge is a book written by philosopher Karl Popper. Published in 1963 by Routledge,[1] this book is a collection of his lectures and papers that summarised his thoughts on the philosophy of science. Popper suggested that all scientific theories are by nature conjectures and inherently fallible, and that refutation to old theory is the paramount process of scientific discovery. Should any new theory survive more of such refutations, it would have a higher verisimilitude and therefore, Popper concluded, closer to truth.
http://en.wikipedia.org/wiki/Conjectures_and_Refutations
Cite a peer-reviewed scientific paper that shows that warming has stopped. Be careful, you are claiming that a previous trend of warming has stopped so the null hypothesis must be that the slope of the temperature versus time series is not positive. If the calculated slope – within its associated error – overlaps any positive value, then the hypothesis that warming has stopped must be rejected. The lack of statistically significant warming trend over some time period does not necessarily indicate that a previous pattern of warming has stopped.
Mike, the papers (Scafetta, Akasofu etc) don’t show that warming has stopped, just that we are in a cooling phase of a natural warm-cool-warm-cool cycle overlaid on a rising quadratic curve that started long before anthropogenic attribution.
The anthropogenic attribution only occurs during the last 70s – 90s warm phase. The question is: did anthro forcing accentuate that cycle? And if so by how much?
OHC warming has stopped though, what will cause that to resume?
Mike:
Trenberth admits it in Trenberth (2010), and it’s also stated as fact in Katsman and van Oldenborgh (2011):
Of course there’s also Knox & Douglass (2010):
See also Kaufmann et al (2011). First sentence of the abstract:
So we agree that Andy’s statement that global warming “has stopped for 10+ years” is not correct.
So we agree that Andy’s statement that global warming “has stopped for 10+ years” is not correct.
Do we?
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1995/plot/hadcrut3vgl/from:1995/trend/plot/hadcrut3vgl/from:2000/plot/hadcrut3vgl/from:2000/trend
http://rankexploits.com/musings/wp-content/uploads/2011/05/Since20011.jpg
Good job Andy – you have them on the run with those flat-liners!
Mike, at this point I’m not sure whether you’re playing thick or actually thick. This is not an ad hominem attack, let me explain:
You asked for peer-reviewed citations. I gave four of them. One of them specifically states “it has been unclear why global surface temperatures did not rise between 1998 and 2008”.
Andy plotted the trend since 2000, and showed Lucia’s excellent analysis graph since 2001. All showing the same thing – no warming over the past 10 years. And then you ask whether we are all happily agreed that Andy’s statement is incorrect!
Remember (and I really shouldn’t have to point this out) the null hypothesis in this case is that the warming trend that we’ve been measuring since 1850 or so will continue at about 0.45°C/century. Any decade-level warming above this can be regarded as supporting AGW, any rate below this is not.
Bob, it is you who have moved the goalposts by pulling out a 0.45°C/century warming trend as a given. Perhaps he meant to write that, but that’s not what he did write. If use of precise language makes me thick, then so be it.
Not just sceptics Nick and not a hypothesis either, just empirical science.
First to fill in the blanks: climate variability of magnitude sufficient to cause the recent hiatus in warming is caused by internal and external phenomena (known “natural effects” e.g. ocean oscillations, multi-decadal scale cloud cover changes, cosmic ray-sunspot-magnetism effects, solar/lunar/celestial cycles) of potential magnitude to produce an ice planet in the past or temperatures in the past that were warmer than present (see Bob D’s explanation of feedback re your irrelevant blank in this case).
The internal system modulator is the hydrologic cycle. It speeds up or slows down as required to maintain balance in response to external phenomena e.g. the global average time for precipitable water vapour to remain in the atmosphere is 9 days. But the strata within troposphere and stratosphere behave differently and while TPW may be increasing at near surface altitude as it has recently, TPW has been decreasing in the upper troposphere and stratosphere. The total averaged effect has been a decrease in total column water vapour prior to about 2000 and relatively stable levels this century.
AGW is a hypothesis on the other hand and it postulates a positive feedback from water vapour causing accelerated warming. The hypothesis is falsified simply by empirical measurement of water vapour and temperature measurement where it matters most in the upper troposphere above the tropics but the effect has failed to eventuate. One of the prime reasons that sceptics identify as the root of the false hypothesis is the failure to adequately account for cloud cover effects and to ascribe a physical mechanism to cloud nucleation along with pollution. This is where Svensmark comes in along with others with alternative climate driver hypotheses and in the case of Svensmark, experimental support from Aahus and CERN CLOUD.
What we see now is recognition that natural variability has overridden what was previously thought to be an unassailable anthropogenic forcing and an odd scramble to “explain” the hiatus (e.g. Kaufmann et al) that allows the appenditure of “but scientists expect warming to resume soon”. because it is all in terms of AGW and STILL studiously avoids attribution of the natural phenomena described above to climate except for a cursory nod to “natural variability” This is the official position of the Ministry for the Environment (Climate Change):-
They cite Easterling and Wehner 2009 (a rather simplistic analysis) who state:-
Loehle and Scafetta 2011 (a more complex analysis that assumes an anthropogenic forcing for their exercise) show that the present period is more likely to be 30 years of hiatus or cooling. This is obviously problematic for the notion of anthropogenic “forcing” if natural variation holds sway now and did prior to anthropogenic forcing attribution when the “longer-term warming” commenced i.e. AGHG emissions are an impotent forcing of insufficient magnitude to produce the predictions of catastrophic sea level rise etc and empirically the predictions are not on track.
BTW, just because [some climate] “scientists expect warming to resume soon” does not mean that is a fait accompli. Some astrophysicists expect a cool phase for the next 70 years as a result of a predicted solar grand minimum – it’s climate science vs astrophysics but we will have to wait and see which group is correct. I’m picking it will be the astrophysicists because their empirical correlations are vastly superior to those of climate (AGW) science but in both cases, correlation does not imply causation and neither are the projections of each a future certainty. See for example the obvious basis for Loehle & Scafetta 2011:-
EMPIRICAL EVIDENCE FOR A CELESTIAL ORIGIN OF THE CLIMATE OSCILLATIONS AND ITS IMPLICATIONS
Scafetta, Submitted May 2010
http://www.fel.duke.edu/~scafetta/pdf/scafetta-JSTP2.pdf
Then there’s:-
De Jager and Duhau. 2011
Niroma, 2009
Laken, Kniveton, and Frogley 2010
H Svensmark, Bondo, and J Svensmark 2010
Shaviv and Veizer, 2003
Kirkby 2008
Holton, 2010
Akasofu 2010
Abdussamatov 2009
Beer, Mende, Stellmacher 2000
Nuzhdina 2001
Swingedouw, Terray, Cassou, Voldoire, Salas-Mélia and Servonnat 2010
Borchert, 2010
McLean, de Freitas, and Carter 2009.
Probably plenty others to ignore as well.
Nick, did you ever answer this question re Trenberth’s claim?
“From where exactly do we get the radiation imbalance, and what is its magnitude?”
Yes he did, but up here.
The indenting is getting confusing.
This conversation needs a separate thread. I’ll pick a title from the first three suggestions, unless there’s a consensus to use one of the open threads. Nested indenting of comments is now reduced to four levels to help reduce confusion. When answering a comment, preface with something like commenter@time,date.
Or make a better suggestion. 🙂
Mike Palin says:
August 4, 2011 at 9:25 am
When I say “global warming stopped for 10+ years”, what I mean is that the rate of increase over this period is zero. (with the usual caveats about statistical significance etc)
Similarly, if I accelerate along a road and then maintain a constant velocity for an hour, it is reasonable to state that “acceleration has stopped” over this period. It says nothing about what will happen next, nor does it contradict the fact that the linear trend is one of increasing speed from the point at which I started the journey.
I’m not moving goalposts. My “null hypothesis” comment was an addendum to my main point which was that there has been no warming (at all, not just over and above the 0.45/century average) over the last 10 years.
So what we have is:
1) No warming over the past 10+ years (Andy was correct)
2) On top of that, obviously no warming above the 0.45°C/century, which is the actual null hypothesis.
Brilliant stuff Bob. This is the best show in town. I got my popcorn and armchair….
Andy, if you take a look at the plots of temperature-time series that you linked to in your comment at 10:11 am, you’ll see that the slopes overlap positive values within their stated margins of uncertainty. That means the hypothesis that a warming trend has stopped is falsified and must be rejected. This is a subtle, but important point. Trends over short time intervals have slopes with larger envelopes of uncertainty. To resolve the trend in a statistically meaningful way (i.e. reduce the uncertainty in the slope), a longer time period must be used and you know what happens then.
The uncertainties on the derivative of the slope (= acceleration of the temperature-time trend) are even larger, so that will not help either.
Dr. Palin, I call your response pedantic claptrap. How many decimal places of a degree are you suggesting is relevant?
“If you take a look…” Did you think he hadn’t yet taken a look? Supercilious CO2 venting.
(from the guy in the back in an armchair with popcorn …. and beer)
One decimal place is sufficient to falsify the hypothesis that warming has stopped in this case. Looking at a plot and understanding it are not necessarily equivalent.
OK, so you could have said “If you comprehend…”. Either way it is supercilious.
Now, back to the matter of the point of a degree. ARIMA trend = Negative 0.111
Can you supply a reference which describes a warming trend of 0.1 degree C or greater for the past decade?
Mike, I not really making an hypothesis that the warming has stopped. I am merely stating that the linear trend over the last 10 years shows no increase in GAT, with the caveat I stated previously about statistical significance.
Of course, Phil Jones famously said (in his interview with Roger Harrabin of the BBC) that there has been no statistically significant warming since 1998. He has since changed his mind on this (which has raised some questions on what his understanding of statistics is).
Doug Keenan recently published an Op Ed in the WSJ on statistical significance, arguing that all of the warming in the 20th Century has no statistical significance.
Speaking as someone with a Maths degree who never really fell in love with Stats (lies, damn lies, etc) I am actually more interested in the Maths behind it that the actual data, and so I do appreciate that you might find my previous language sloppy.
This is why I also get irritated by statements using terms like “warmest year on record”, that have no scientific meaning, in the sense they say nothing about trends, which is what we are really interested in.
Andy, I accept that you used a turn of phrase that was not precisely what you meant to communicate. It happens to the best of us.
Phil Jones was precise in his language. The warming trend from 1998 to the time of the interview lacked statistical significance, but only very slightly. When data for subsequent years became available, the warming trend from 1998 became significant.
To this:-
“When data for subsequent years became available, the warming trend from 1998 became significant”
This should be added:-
but only if the series is terminated during the last El Nino event and not during the subsequent La Nina event.
Mike Palin,
You say:
I know next to nothing about what you’re saying, except that your conclusion is significant. Would you help me understand this, please? Although I will quite understand if you’re too busy to cover such elementary topics.
1. Which time series? I think Andy cited two.
2. Which slopes are overlapping?
3. What does overlapping mean?
4. Overlapping which positive values?
5. No margins of uncertainty are stated. What are they?
6. How does this falsify the cessation of a warming trend?
I have seen graphs similar to the Wood for Trees graph Andy cites, some with slightly cooling trends, beginning around the same time. Whether it’s slightly warming or slightly cooling, there’s no doubt that the strongly warming trends we’re told to expect have not materialised, so natural factors are overpowering the anthropogenic factors, which tells me we’re not so powerful after all.
I am not led to conclude, with Hansen, that “… if we burn all reserves of oil, gas and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty”. [Storms of My Grandchildren]
Now, where did I put that seminal paper describing the CAGW theory?
Richard, I’ll answer your questions to the best of my ability and recognising that I have a day job.
First, let’s get on the same page with some fundamentals. Do you agree that “warming” in a temperature time series is defined as a trend with a positive slope? (Let’s leave the potential causes out of the discussion.) Do you also agree that calculation of a slope for any set of real data that is not perfectly linear will entail some uncertainty? Do you agree that the appropriate statistic to estimate this uncertainty is the standard error of the slope?
I have a day job, too.
To your first two questions: yes and yes. Let me answer your third when I’ve found out what standard error means. I keep forgetting.
Thanks for your patience.
1. Which time series? I think Andy cited two.
Both the WoodforTrees trend of Hadley Centre data from 2000 to 2011 here:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1995/plot/hadcrut3vgl/from:1995/trend/plot/hadcrut3vgl/from:2000/plot/hadcrut3vgl/from:2000/trend
and the plot of NOAA data here:
http://rankexploits.com/musings/wp-content/uploads/2011/05/Since20011.jpg
2. Which slopes are overlapping?
Let’s consider the plot of the Hadley Centre data first. The plot data can be downloaded from the WoodforTrees link. I calculate a slope of +0.021C/decade with an uncertainty of +/- 0.025C/dec. This uncertainty can be calculated using Excel – it is the standard error of the slope (= standard deviation of the slope divided by the square-root of the number of data). The statistically valid slope therefore falls between +0.046C/dec and -0.004C/dec. This range significantly overlaps (includes) positive values.
For the plot of the NOAA data, the uncertainties in the slope are shown as dashed curves. The figure caption gives the ranges in brackets. For the trend shown in red, the slope is -0.003C/dec with a bracket of +0.094C/dec and -0.100C/dec so the uncertainty is +/- 0.097C/dec. Again, the statistically valid slope significantly overlaps positive values.
3. What does overlapping mean?
I take “overlapping” to mean “include” or be” indistinguishable from”.
4. Overlapping which positive values?
Any positive value. As we have agreed, any temperature-time series with a positive slope defines a warming trend. Both of the slopes shown in the plots are statistically indistinguishable from positive values up to +0.046C/dec and +0.094C/dec, respectively, and therefore falsify the hypothesis that “warming has stopped” over the time period plotted.
Do they exhibit statistically significant warming trends? No. Why? Because they are also statistically indistinguishable from zero and negative values down to -0.004C/dec and -0.100C/dec, respectively, but this is irrelevant to the point I was arguing.
5. No margins of uncertainty are stated. What are they?
See 2 above.
6. How does this falsify the cessation of a warming trend?
See 4 above. In summary, the rejection of a hypothesis depends as much on the statement of the hypothesis as the data used to test it. The temperature-time plots shown have slopes that – statistically speaking – are indistinguishable from being positive (= warming trend) and, therefore, falsify the hypothesis that “warming has stopped”.
Mike,
What the results show is that there has been no statistically significant warming or cooling over the past decade.
Now you can spin this as meaning that this doesn’t prove that warming has ceased, and yes, you are technically correct, since we don’t have a statistically significant cooling either.
However, considering that the previous warming trend was 0.045°C per decade, one might be excused for being a little disappointed to discover that what was normal is now the upper limit of the uncertainty band. After all, the IPCC was “projecting” about 0.21°C per decade at this point, as per their A1B scenario.
Bob D, I agree with your first two sentences. As to your third, I’m not at all disappointed that the amount of warming is less than one of several projections that the IPCC presented. I hope that they are wrong about the amount of warming, sea level rise, and ocean acidification in the long term. I also hope the All Black win the World Cup. Based on past trends, I won’t hold my breath for either.
Mike,
Thank you for your informative answer, and thanks for describing the standard error. Your comment that there’s been no statistically significant warming this century stands in contrast to other prominent statements to the effect that this decade has been either the warmest or the second warmest decade ever. Of course, there is a difference between warmth and warming. But forgive me if I don’t start believing the (wholly undefined) CAGW story just yet. It’s just so undramatic.
On that point, you seem to speak with a voice both accurate and moderate, yet stand with those who speak inaccurately and immoderately, yelling insults and calling for increased restrictions and higher taxes. Sometimes I hear them when you speak, but I never hear you when they shriek.
Richard,
The most recent decade could well be the warmest on record, even though the warming trend through the decade may not have been statistically significant. The two statements are not necessarily contradictory. As I have tried to demonstrate, calculating the slopes of decade-scale temperature-time series inevitably entail large uncertainties that limit their value as definitive tests of just about anything. Comparing average temperatures between decades may or may not be valid.
Mike,
I’d be grateful if you (or anyone else!) could have a look at this time series from WoodForTrees.
http://www.woodfortrees.org/plot/hadcrut3vgl/from:2001/trend/plot/hadcrut3vgl/from:2001
There is a clear negative slope in this ten-year time series, which absolutely falsifies the hypothesis that warming has continued. Do you agree?
Actually, even from 1997 the warming slope is pretty insignificant, but I can’t measure it.
woodfortrees.org is a great site to have a play with data. Using it does not replace the thorough analysis that would accompany such data through the peer review process. Nonetheless, your choice is illuminating because, although it looks damning, once again the uncertainty (+/- 0.0504C/dec) on the calculated slope (-0.0502C/dec) of the temperature-time series is just large enough that it does not permit a warming trend to be falsified.
The data from 1997 to present give the same story: +0.022C/dec with an uncertainty of +/- 0.039C/dec.
Bob D @ August 3, 2011 at 10:43 pm
Hi Bob, sorry for the delay in response, like us all I’m a little busy.
I accept that you don’t like the result found by Trenberth et al. but that doesn’t make it wrong, it is supported by a number of observations (and models) but if you have an alternative calculation (peer reviewed) of the radiative imbalance I’b be please to have a look at it.
This is however a bit of a tangent. I’m more interested in the alternative hypothesis that you presented for heat transfer through the atmosphere (advection etc.). Do you have any peer reviewed sources that support this? Trenberth seems to cover it in his paper so if you have any alternative estimates for the scale of this effect that would be interesting.
Finally you asked why if Venus has had a run away green house effect why hasn’t it occurred on earth. The answer is of course that Venus is closer to the sun (as described in the paper you sited in the same post).
Nick,
Wow, were you even listening? You say I “don’t like the result found by Trenberth”! Please try to comprehend the following:
The result found by Trenberth is not an observed result. It is, in its entirety the modelled result of Hansen (2005).
As for a peer-reviewed alternative calculation based on observations (not models), nothing is easier, since I’ve already provided one:
http://www.pas.rochester.edu/~douglass/papers/KD_InPress_final.pdf
Knox & Douglass find -0.15W/m2 Ftoa. This figure is backed up by three other peer-reviewed sources.
You should actually read the paper one day, it’s only three pages long.
Bob, Knox does not measure the radiative imbalance either. It only uses (cherry picks) data from OHC which shows cooling between 2003 and 2008 and then uses a model to estimate radiative imbalance.
Perhaps you could link your supporting papers.
Nick,
I gather from this that you have completely misunderstood the paper. They measure the actual ocean heat content change during the full lifetime of the ARGO network (not cherry-picked). They find negative trends. They check with other papers which also all show a negative trend, except one which used early data without correcting for known pressure problems (see Willis 2007 and 2008).
They then calculate the Ftoa from this negative trend, not by a model, but by simple arithmetic (J/year converted to W/m2).
So we have a measured negative imbalance. This, as they point out, is in direct contrast to the modelled positive imbalance claimed by Hansen and copied by Trenberth.
See the References in the Knox & Douglass paper.
This is textbook stuff. It’s just the water cycle.
I thought the heat transfer you were proposing was far higher than what is accepted in mainstream climate literature. As I say Trenberth includes it in his model so why do you think the effect is larger than what he attributes to it?
Nick,
Two reasons:
1) If you read Trenberth (2009) you can’t help but be struck by the huge uncertainties in all his values. The imbalance we’re looking for is less than 1W/m2. This amount is easily swamped by the uncertainties in his assumed numbers.
2) There clearly is no imbalance. The earth has been shedding heat quite easily. I’m suggesting that simply assuming that the earth cannot get rid of its excess heat except via radiation is a flawed assumption. The ‘excess’ heat has been shed. Now it’s up to Trenberth etc. to tell us why the system is able to shed its heat so easily, and where their models went wrong.
Nick,
It doesn’t have to be far higher. It only has to be 0.85W/m2 higher to completely cancel out the assumed imbalance. That’s a tiny amount compared to the uncertainties in Trenberth’s assumptions. Remember, the models don’t simulate the water cycle very well.
Nick, I think you missed the point of my statement. You say:
I’m well aware that Venus is closer to the sun. However, the runaway greenhouse effect, if you read it carefully, doesn’t depend on distance from the sun. Any incoming solar radiation that is prevented from leaving by increased GHGs will raise the temperature. In the presence of water-filled oceans, this will cause increased water vapour in the atmosphere (ie: increase GHGs) which will trap more heat, raising the temperature, producing more water vapour and so on.
In the case of Venus, the process only stopped (apparently) when all the oceans boiled away and the water vapour escaped to space, which allowed the system to stabilise.
“However, the runaway greenhouse effect, if you read it carefully, doesn’t depend on distance from the sun” Actually Bob, it does. From the paper you cited
“For fully saturated, cloud-free conditions, the critical solar flux at which a runaway greenhouse occurs, that is, the oceans evaporate entirely, is found to be 1.4 times the present flux at Earth’s orbit (S0). This value is close to the flux expected at Venus’ orbit early in solar system history.”
You may like to refer to http://en.wikipedia.org/wiki/Positive_feedback and go down to the section on Climatology. This describes why the earth has not suffered from runaway temperatures (but is still subject to positive feedback effects)
Nick,
You have got to love your Wiki reference to positive feedback
The image of the sheep running around in a state of alarm is just classic!
Nick,
The article cites the S-B law as the reason that runaway warming can’t occur. So explain to me, please, why would the S-B law provide a limit at higher temperatures?
Richard C @ July 17, 2011 at 5:38 pm
Hi Richard, regarding atmospheric water vapor levels what is your reaction to Dessler & Davis (2010) which finds Paltridge et al (2009) to be an outlier compared to the other research in this field. Probably due to their use of radiosonde (which they admit is problematic).
Vonder Haar et al (2005) say they find no significant trend and Solomon et al (2010) only find a decrease in WV after 2000 and that WV is an important driver of decadal global surface climate change.
Just to clarify are you claiming that increasing temperature does not increase the level of WV in the atmosphere?
Nick, just look at the WV metrics for yourself, you will always be able to find papers that appeal to your confirmation bias I’m sure but there’s nothing like looking at the empirical evidence (not modeled) for youself :-
http://climate4you.com/ (click “Greenhouse Gasses)
Over a period when temperature has been increasing and then stabilized, WV was decreasing (with fluctuations) and then stabilized. The positive WV feedback from AGW has not eventuated, instead there’s a negative feedback and the total effective amount of greenhouse gases in the atmosphere has not significantly increased over the last 60 years. The changing water vapour level offsets almost all of the warming effect of CO2. i.e. WV is a natural modulator and of course “WV is an important driver of decadal global surface climate change”
It’s clearly laid out here, see “The Saturated Greenhouse Effect”
http://www.friendsofscience.org/assets/documents/The_Saturated_Greenhouse_Effect.htm
Take a good long look at Global Relative Humidity 300 – 700 mb 1948 -2008. This is the critical AGW pressure zone where the WV amplification is supposed to be taking place but it isn’t (and no “hotspot” either).
And no, I don’t claim that “increasing temperature does not increase the level of WV in the atmosphere?” It does but it’s transitory (hence the temporary fluctuations) and WV levels do not necessarily change in the same way at all the different pressure levels as can be clearly seen in the metrics above.
Richard, thanks for the link to the NOAA data, it is however the same data as is used in Paltridge et al. and refuted in Dessler & Davis.
In fact climate4you explicitly mentions the Dessler & Davis paper as follows “It has, however, recently been suggested that it that the negative long-term specific humidity trends shown by the above data series are doubtful, and that instead the trend is towards increasing specific humidity (see, e.g., Dessler and Davis 2010).”
The full text is here http://geotest.tamu.edu/userfiles/216/Dessler10.pdf and is worth a read as it explains exactly why the data set you linked seems to be different (and less reliable) from the other four data sets that show increasing humidity.
Garth Paltridge comments on the Dessler and Davis paper here, see:-
Dessler 2010: How to call vast amounts of data “spurious”
Scroll down to:-
Guest Post by Garth Paltridge
Re The Dessler and Davis Paper
http://joannenova.com.au/2010/11/dessler-2010-how-to-call-vast-amounts-of-data-spurious/
Also you might like to read the following account of the handling (and rejection) of Paltridge, Arking and Pook’s article at Journal of Climate. See:-
A Peek behind the Curtain
Garth Paltridge writes: LOADED DICE IN THE CLIMATE GAME
http://climateaudit.org/2009/03/04/a-peek-behind-the-curtain/
This bit is for you Nick:-
“Of course Dessler and Davis are entitled to their opinion, and may even be proved right one day. But at the moment it won’t do the discipline much good if people assume simply on the basis of the existence of their paper that the issue is now resolved.”
Nick, don’t forget the ISCCP column water vapour (top graph Climate4you).
It’s also worthwhile looking at what D&D try to characterize as “old” and less reliable. It’s near real-time :-
NCEP/NCAR Reanalysis I (1948-present)
This reanalysis was the first of it’s kind for NOAA. NCEP used the same climate model that were initialized with a wide variety of weather observations: ships, planes, RAOBS, station data, satellite observations and many more. By using the same model, scientists can examine climate/weather statistics and dynamic processes without the complication that model changes can cause. The dataset is kept current using near real-time observations.
http://www.esrl.noaa.gov/psd/data/gridded/reanalysis/
Remember it’s a model like all the other D&D reanalyses, only the inputs are different (radiosonde vs satellite for WV, both have reliability issues) but it is a relatively long series:-
Overview of current reanalyses
http://reanalyses.org/atmosphere/overview-current-reanalyses
D&D have a problem this century though (see Figure 3). None of the reanalyses show a rising trend in spec humidity at 300hPa, they are either flat or decreasing.
D&D are also wrong about the 1998 El Nino spike. That can clearly be seen in Paltridge Fig 3 tropics.
I also question D&Ds reproduction of the NCEP/NCAR time series data (Figure 3). They have it dropping from 0.5 g’kg to 0.4 1980 – 2009 but Climate4you shows a drop 0.35 – 0.3. That’s not a lot different than the others in Fig 3. The NCEP series only starts at 0.375 in 1948. Plus the shape is nothing like the Climate4you plot and the latest Climate4you update is 0.3 g’kg June 2011 whereas D&D stops at 0,4 2009.
I think the D&D Fig 3 plot of NCEP is bogus, meaning Figures 1 and 2 (same data?) and the analysis as a whole is probably bogus as well. I’ll be getting in touch with Garth Paltridge about this.
Thank’s Nick, you’ve done the sceptics a huge favour by putting the spotlight on D&D.
Bob D, the reason the Stefan–Boltzmann law limits positive temperature feedback is that it is a 4th power law. As explained in the Wikipedia article. If you are trying to lead me to a specific conclusion how about you just state it?
All right then, explain to me how radiant energy that is unable to escape at T1, is able to escape at T2, where T2>T1, even though the only difference is the energy is greater by a power of 4, but still at the same frequency?
If the radiation is blocked by the GHGs in the atmosphere, how does it escape in a situation where there are more GHGs blocking it, just simply because there’s more energy? After all, the atmosphere is effectively opaque in these ranges. Now you could argue that the higher temps shift the mean wavelength, but I doubt it’s enough to cater for it.
And if it’s true that an increase in temperature means the energy is suddenly able to escape where it was blocked before, why does this not happen for small increments? In other words, the earth heats up due to an increase in CO2, but loses it immediately due to the S-B law.
What is the mechanism that allows the energy to escape at higher energies with higher GHGs, but stops it escaping at lower energies and lower GHGs is the question.
By the way, I’m not trying to trick you, I’ve just never heard a good reason before.
Bob D, reading back through the comments your original point was that climate models neglect convection.
“This is the main flaw in the logic, since most GHG arguments seem to focus just on radiation”
This is clearly not the case as evapotranspiration it is specifically measured in Trenbreth’s paper. Sorry for getting sidetracked.
Nick,
I’m referring of course to the excess energy apparently retained in the system by GHGs. And Trenberth hasn’t measured the evapotranspiration, he’s assumed it, within large error bars. Error bars easily big enough to swallow the entire “imbalance”.
What I’m saying is that the climate system is significantly more complex than their simple models make out. We do not understand the subtle changes nearly well enough to be able to state categorically that a radiative imbalance of 0.85W/m2 actually exists on good old planet earth, and that we understand exactly how any perturbation plays itself out.
Yet that is precisely what the whole AGW assumption stands on.
Richard, your original comment was that: “AGW hangs on the thread of amplified WV levels in the GHG critical pressure zones in the upper troposphere (300 hPa, 400 hPa) after which heat is free to dissipate to space. However, AGW falls flat on it’s face at the first hurdle because WV levels are falling there and immediately above and below.”
Given that:
– The authors of the study you cite say ”…radiosonde-derived humidity data must be treated with great caution, particularly at altitudes above the 500 hPa pressure level”
– And admit that “It is of course possible that the observed humidity trends from the NCEP data are simply the result of problems with the instrumentation and operation of the global radiosonde network…”
– And four reanalysises of satellite data find the opposite to what you contend
Do you not think that your conclusion “AGW falls flat…” is possibly a little extreme?
Ignored the ISCCP column water vapour huh?
Yes I don’t dispute that there are uncertainties with balloon data but (as Jo Nova puts it) “satellite channels have equally large (if not larger) uncertainties. They can’t pick out humidity specifically, and they can’t resolve say, 10 km from 11km. They cover thick slabs of the atmosphere (Channel 12 gets results from the region that is 8 -12 km up). In the end the only thing we know for sure is that it’s hard to measure humidity 12 km off the ground.”
The NCEP series though, is a contigious 63 year (and counting) series and cannot be discounted despite Dessler and Davies attempt to disparage 28,000,000 soundings and the work that goes in to retrieval of that data. The satellite series that D&D look at are 29 years at most and 7 years at least (a similar situation exists in sea level series – tide guage vs satellite). The D&D ERA40 series has a falling trend 1979 – 1996 (during a planetary warming phase and up to the 1998 El Nino event), The JRA series is flat from 1979 -1996 (during a planetary warming phase and up to the 1998 El Nino event). Only the MERRA and the very short and interim ECMWF series are rising up to the 1998 El Nino event. All series pivot about the 1998 El Nino event and all are either flat or falling after that event (despite a continuing rise in CO2 levels).
D&D have also made a gross error (possibly intentional) in that they have not plotted tropical 300 hPa NCEP data i.e. they are not comparing like-for-like. What they have plotted will be very interesting to find out, it looks suspiciously like global average data – not tropical, and far too choppy e.g. why the 1990 peak higher than the 1980 peak? That does not occur in the Climate4you plot of 300 hPa data. The D&D NCEP plot looks like a summation of several pressure levels, so what data did they really use for the 300 hPa plot?
Vonder Haar et al (2005) is based on the NASA water vapor data set called NVAP and states:- “By examining the 12 year record [1988-1999], a decrease of TPW [total precipitable water vapor] at a rate of -0.29 mm / decade is observed. This relationship is significant at the 95 % but not at the 99 % level”. The NASA NVAP data set (more comprehensive than any other) has (controversially) not been released since then (I wonder why)
So no, I don’t think that my conclusion “AGW falls flat…” is possibly a little extreme. My conclusion is consistent with the multiple lines of evidence, the others being the absence of the predicted AGW hotspot and the other being that the total effective amount of greenhouse gases in the atmosphere has not significantly increased over the last 60 years.
Miskolczi’s theory on the other hand implies that adding CO2 to the atmosphere would reduce relative humidity, (contrary to climate model assumptions) so when I see this 60 year series of global relative humidity 1948 -2008 (yes NOAA ESRL again) trends all reducing at 300, 400, 500, 600 and 700 hPa (mb) except flat from1988 onwards for 500 and 600 in this plot:-
http://www.friendsofscience.org/assets/documents/GlobalRelativeHumidity300_700mb.jpg
the picture is consistent with theory and other lines of evidence and I have no reason to think that the 60 year trends should somehow be a mirror image of what has been plotted.
Since as you admit there are uncertainties with the radiosonde humidity data then you must accept that they cannot disprove AGW, just as the satellite data does not prove it.
You may well consider that the radiosondes support Miskolczi’s theory but even Dr Roy Spencer (author of The Great Global Warming Blunder) thinks he is on the wrong track saying of the theory “I know of no one else who believes this, and it seems to fly in the face of common sense.” and “…few people believe long-term trends in radiosonde humidities.”
http://www.drroyspencer.com/2010/08/comments-on-miskolczi%E2%80%99s-2010-controversial-greenhouse-theory/
I apologise for the departure from peer reviewed sources but I understand that you might respect Dr Roy’s opinions more than those of Dessler and Davis.
Nick, Scepticism 101.
I’m someone who, being afflicted by a natural disposition to confirmation bias from time to time and acceptance of missives from those of more lofty stature than myself when I really should be activating my BS detector, must actively cultivate a discipline of scepticism of my own and other interpretations, and statements emanating from preeminent scientists i.e. respect – yes, unquestioning acceptance – no..
For this reason (unlike almost all of the unsceptical who seem to gravitate to the AGW side) I do not accept all statements at face value from preeminent scientists or identities whether they are in the luke-warm camp (e.g. Spencer, Watts) or radically anti-AGW (e.g. Claes Johnson) even though I would place myself between the two.
Given that Spencer and Miskolczi are at loggerheads (and resolution of the issues is a long way off) and huge egos are at play (I followed their tetchy debate – see, AGW sceptics don’t just accept each others opinion without question), I’m not surprised at Spencer’s statement (it’s to be expected from a luke-warm AGW disposition) but what you quote is his opinion, not mine by default (see above). I very much doubt that Spencer did a survey for his “few people” quote and just because he personally doesn’t know anyone who subscribes to Miskolczi’s theory or aspects of it, doesn’t mean there aren’t any people who do and besides, it’s the empirical aspect that is significant to me. His numerical theory needs a peer reviewed rebuttal (none yet) from someone whose grasp of mathematics is orders of magnitude better than mine and a response from Miskolczi for me to ponder and so on (i.e. as with AGW, it will take some time to play out – the normal scientific process in action).
I accept there are uncertainties with radiosonde AND satellite humidity data but I don’t accept that the uncertainties in radiosondes are enough that if rectified would turn a 60+ year trend from negative to positive. In this respect, the radiosondes disprove AGW and support the Saturated Greenhouse Effect until if and when fundamental systemic and/or technological errors (or whatever) are found, documented and rectified etc. I’m still waiting for your countervailing scenario. It doesn’t have to be technical, just plausible reasoning. If you can’t come up with something, your condemnation of radiosondes is just an arrangement of pixels on a blog page.
Do you also extend your condemnation to ARGO data trends Nick?
Richard C I assume you are aware of http://www.realclimate.org/docs/Rebuttal_Miskolczi_20100927.pdf even though it is not part of the peer reviewed literature, do you know if Miskolczi has responded to it?
As for my countervailing scenario it is the same as that generally accepted among climate scientists:
As CO2 rises in the atmosphere it traps heat and causes the earths temperature to rise. This triggers positive feedback in the form of water vapor causing further temperature rises until a new equilibrium temperature is reached.
The CO2 emitted by humans if unchecked is likely to increase the global temperature to dangerous levels.
Given the uncertainties of the radiosonde readings and the conflicting measurements from satellites that we have discussed I don’t think their data is sufficient do disprove the theory I have presented above.
There’s plenty of “rebuttals” in the blogosphere but the real science will play out in the literature (and the climate) over time. Given the Spencer – Miskolczi showdown, I don’t think RC will get any traction with him until they put it in press.
The countervailing scenario I am looking for is specific to radiosondes and is a plausible explanation of what the systemic error actually is that causes a 60+ year (starting way before satellites) trend to be negative instead of positive for such a large number of separate soundings. Randel and Wu speculate on “jumps” causing a cool bias but how does such a cool bias actually happen over the course of 60+ years from so many separate soundings.
It’s the radiosonde operators that you will ultimately have to convince with your reasoning not me but you may as well work it out via me first because until you have it perfected the radiosonde data still stands and AGW is disproved (and it will have nothing to do with satellites – that’s just the basis of your speculation, there’s no root cause there).
The data (as I have detailed – see up-thread) is not as conflicting as you make out. There is only 2 that conflict prior to 1998, 1 of those is interim and all are in sync after the 1998 El Nino. The D&D plot of 300 hPa NCEP looks highly suspect so until I’ve checked with the database and Garth Paltridge I don’t put much stock in their speculation or analysis
BTW, I see you citing Mears et al 2005 in support of the hotspot. If it’s Mears and Wentz, they study LOWER troposphere temperature. The hotspot should be in the UPPER troposphere (300 hPa). See this article that takes RC to task by referencing the IPCC diagrams of the predicted hotspot:-
http://rankexploits.com/musings/2008/who-expects-a-tropical-tropospheric-hot-spot-from-any-and-all-sources-of-warming/
The Effect of Diurnal Correction on Satellite-Derived Lower Tropospheric Temperature
1. Carl A. Mears and
2. Frank J. Wentz
http://www.sciencemag.org/content/309/5740/1548.short
Re this:-
“As CO2 rises in the atmosphere it traps heat and causes the earths temperature to rise. This triggers positive feedback in the form of water vapor”
Lot’s of problems with this. I suggest you join me on this thread (nobody else is) where I’m taking this scenario to task:-
https://www.climateconversation.org.nz/2011/08/just-one-fact/#comment-64413
I’m investigating heating effect by radiation including evaporation (solar SW vs GHG DLR) in respect to Trenberth, Fasullo and Kiehl’s Earth’s Energy Budget which seems to be the de-facto AGW paper that we must address in lieu of a falsifiable hypothesis. I’ll be pursuing the topic on an on-going basis even if no-one else is. I’ve got much more to add BTW
Nick, I’ve checked the Climate4you spec. humidity plot and discovered that it is for 90N – 90S, not 20N – 20S (tropics as in the D&D Fig 3 plot) so I’m wrong to compare one to the other. However I still don’t know what radiosonde data D&D have plotted in Fig 3 now that I’ve checked the ESRL database here:-
http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl
Here’s the raw data for these parameters:-
300mb Pressure Level Specific Humidity (gr/kg)
Latitude Range used: 20.0 to -20.0
Longitude Range used: 180.0 to 180.0
Weighted area grids = yes
http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Specific+Humidity+%28up+to+300mb+only%29&level=300&lat1=20&lat2=-20&lon1=180&lon2=180&iseas=0&mon1=0&mon2=0&iarea=1&typeout=1&Submit=Create+Timeseries
And the plot of that data:-
http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries.pl?ntype=1&var=Specific+Humidity+%28up+to+300mb+only%29&level=300&lat1=20&lat2=-20&lon1=180&lon2=180&iseas=0&mon1=0&mon2=0&iarea=1&typeout=2&Submit=Create+Timeseries
This plot from 1979 – 2009 does not look like the D&D plot. If we take 1980 for example, the annual average of the 12 ESRL monthly datapoints is 0.6 g/kg.but the D&D plot shows 0.5. Similarly 1990 ESRL 0.62 D&D 0.51, 1995 ESRL 0.54 D&D 0.45, 1998 ESRL 0.488 D&D 0.45, 2000 ESRL 0.4 D&D 0.4, 2005 ESRL 0.48 D&D 0.4, 2009 ESRL 0.49 D&D 0.4.
Except for 2000 where ESRL corresponds exactly to D&D, the other D&D values seem about 0.1 g/kg too low last century and 0.085 too low this century. Note that ESRL 1998 is the same as ESRL 2009 at 0.49 but D&D has 1998 0.45 and 2009 0.4.
Using the above ESRL values for D&D’s linear trend analysis might work in favour of D&D’s case (except for this century) but the difference in data ESRL vs D&D calls into question what data D&D actually used. I’ve probably got my story checked and sorted enough to make a query to Garth Paltridge now.
What you may not have picked up on is that the ERA-40 reanalysis (triangle symbol series) also uses radiosonde data and that ERA-40 is the new ECMWF 40-year reanalysis. Therefore ERA-40 supersedes the “interim” ECMWF series that D&D have plotted (dot symbol series). This leaves only MERRA and JRA in conflict with NCEP trend-wise (and JRA is essentially flat 1979 – 1998). See:-
ERA-40 Project Report Series No. 2
The long-term performance of the radiosonde observing system to be used in ERA-40
August 2000
Kazutoshi Onogi
http://www.ecmwf.int/research/era/_docs/ERA40PRS_2.pdf
Figure 1 page 25 shows radiosonde distribution by manufacturer January 1988
I cant ascertain why there is such a difference between NCEP and ERA-40 absolute values i.e. where are the ERA-40 adjustments to NCEP documented? There’s a number of plots at the bottom of the report that give a clue but that’s as far as I’ve got.
The following article describes radiosondes, their components and the operation of them:-
RADIOSONDES — An Upper Air Probe
http://www.aos.wisc.edu/~hopkins/wx-inst/wxi-raob.htm
The following is the observing requirements for the GCOS Upper-Air Network (GUAN):-
http://gosic.org/gcos/GUAN-spec.htm
Note the Design Principles and Best Practices e.g.
# Changes of bias caused by changes in instrumentation should be evaluated by a sufficient overlapping period of observation (perhaps, as much as a year) or by making use of the results of instrument intercomparisons made at designated test sites.
I note that Paltridge, Arking and Pook says this about satellites:-
“As with radiosonde measurements, satellite observations of upper-level humidity have their own problems and must be treated with caution. Most work to date concerns analysis of the channel 12 data of the High-Resolution Infrared Radiation Sounder (HIRS) of the NOAA polar orbiting satellites. Channel 12 is located near the center of the 6.7-μm rotational–vibrational emission band of water vapor and is sensitive both to the water vapor emission and to the temperature of a broad layer from about 200 to 500 hPa. Soden et al. (2005) find no trend in the global mean channel 12 radiance. Since model simulations with constant relative humidity also show no trend and simulations with constant specific humidity show a positive trend, they conclude that the HIRS observations are consistent with constant relative humidity. A potential practical issue concerns the fact that the positive trend for the constant q simulation appears only in the last 10 years of the 24-year simulation. Perhaps more to the present point, Bates and Jackson (2001) find wide variations in the HIRS-derived RH trend for different latitude zones. The trend is negative in the Southern Hemisphere between 10° and 60° S and negative in the Northern Hemisphere between 10° and 40° N. It is significantly positive only for the tropical zone from 10° N to 10° S.”
And
“There are still many problems associated with satellite retrieval of the humidity information pertaining to a particular level of the atmosphere— particularly in the upper troposphere. Basically, this is because an individual radiometric measurement is a complicated function not only of temperature and humidity (and perhaps of cloud cover because “cloud clearing”
algorithms are not perfect), but is also a function of the vertical distribution of those variables over considerable depths of atmosphere. It is difficult to assign a trend in such measurements to an individual cause.”
It’s a case of two evils but one has been around longer than the other.
Turns out that the MERRA reanalysis (the main satellite input based plank of Dessler and Davis) has problems of its own. See:-
A Comparison of MERRA and NARR Reanalyses with the DOE ARM SGP data
Aaron D. Kennedy, Xiquan Dong, and Baike Xi
Shaocheng Xie and Yunyan Zhang
Junye Chen
2011 (PRELIMINARY ACCEPTED VERSION)
6% is approximately 1 g kg-1 so MERRA is more than 1 g kg-1 too moist at 300hPa RH in the study location.
This effects radiation.
Figure 1. Biases of ARM continuous forcing (black), NARR (red), and MERRA (blue) relative to the ARM Cloud Modeling Best Estimate (CMBE) sounding profiles during the period 1999-2001 for (a) temperature, (b) zonal wind, (c) meridional wind, and (d) relative humidity. (e)-(h) are the same as (a)-(d) except for the RMSE.
MERRA bias @ 300hPa in the study location
Temperature: 0.25 K (positive and warm)
Relative Humidity: 5% (positive and moist)
Figure 8. Monthly total precipitation measured over the ARM SGP domain by ARM (black), NARR (red) and MERRA (blue) during the period 1999-2001.
MERRA is the outlier, not enough precipitation in the study location.
This “Rebuttal of Miskolczi’s alternative greenhouse theory”, an article by Rob van Dorland and Piers M. Forster cites “A more robust analysis of water vapour changes by Mears et al. (2010) shows that total column water vapour is increasing over the oceans in the period 1988-2009 at a rate of 0.27 +/- 0.08 mm/decade”
So what? That’s just TCWV over the ocean. The “more robust analysis” (Mears et al (2010) turns out to be merely a chapter (page 29) in the report “State of the Climate in 2009” headed
c. Hydrological cycle
1) Total column water vapor—C. Mears, J.
Wang, S. Ho, L. Zhang, and X. Zhou
http://www.indiaenvironmentportal.org.in/files/climate-assessment-2009-lo-rez.pdf
Figure 2.11 shows the over-the-ocean-only 0.27 +/- 0.08 mm/decade TCWV trend (NOTE THAT THE TREND IS A FRACTION OF A MILLIMETRE PER DECADE) that van Dorland and Forster describe as “more robust”. But when we look at GLOBAL TCWV it’s a different story entirely. See the following plot:-
Total Column Water Vapor (cm):
21-Year Deviations and Anomalies of Region Monthly Mean From Total Period Mean Over Global
Go to the bottom windows of this page:-
http://isccp.giss.nasa.gov/products/browseatmos.html
Select a variable:[Total Column Water Vapour]
Select a geographic region: [Global]
View Plot
First, the anomaly baseline is 2.41 Centimetres and corresponds with the Climate4you TCWV plot here:-
http://climate4you.com/ (click “Greenhouse Gasses”)
Second, the data is from the file B128B129glbp.dat but I can’t open it from the ftp site and plot it to obtain a trend but eyeballing the plot reveals that over 2 1/3 decades the procession is:-
1984 24.5 mm
1988 25.1 mm
1992 24.1 mm
1996 25.0 mm
1998 26.0 mm
2000 23.0 mm
2004 23.1 mm
2008 22.1 mm
The trend from the 4 yr values is -0.1098x or -1.098 mm/decade (GET THAT? DECREASING ONE WHOLE MILLIMETRE PER DECADE AND THAT INCLUDES OVER-OCEAN DATA).
Note that this is SATELLITE data, see:-
ISCCP OVERVIEW
http://isccp.giss.nasa.gov/overview.html
TCWV is significantly influenced by evapotranspiration from Northern Hemisphere land (land area greater in the NH (70%) than in the SH (30$)). By looking at over-ocean-only TCWV van Dorland and Forster neglect this most important item.
Miklos Zagoni rebuts van Dorland and Forster here|-
http://miskolczi.webs.com/MiklosZagoni_ReplyToRob.pdf
Dear Dr. Dorland, Dear Professor Forster,
Gentlemen
With full respect, I must say that your attempt to understand Miskolczi’s results correctly was only a partial success.
Bob D, the mathematics of how the Stefan-Boltzmann Law limits the positive feedback due to water vapor is explained in detail at http://en.wikipedia.org/wiki/Idealized_greenhouse_model but this does not give a particularly good intuitive feel for the situation.
You could look at it this way, any positive feedback will always be ultimately balanced by a negative feedback if the negative feedback is of a higher power. Increasing the magnitude of the positive feedback will only result in an increase in output until a new equilibrium is reached.
Consider
X(next) = 1 + 0.5*X – 0.1*X^2
Which finds an limit at 1.531129. Increasing the positive feedback term from 0.5 to 0.6 shifts the limit to 1.741657
Is this clear? It might be worth having a play with the numbers in excel to see what I mean
Nick, you still haven’t provided an answer to my question. Simply pointing me to a modelled idealised equation doesn’t show me that the model is based on basic physics as seen in the real atmosphere.
You have another problem here – the foremost scientist on AGW, Dr James Hansen, believes that a runaway greenhouse effect is possible here on earth. And he believes it’s possible not by moving the earth closer to the sun, but simply by increasing greenhouse gas concentrations.
So if you manage to convince me that the 4th power law provides a limiting action on the warming (and you still have to do that) you face a bigger problem – a top NASA scientist disagrees with you.
I’m sorry to hear you are still unconvinced that the Stefan-Boltzmann Law prevents lower order positive feedbacks from running away. I don’t really want to move on to other topics until you understand this point as it is a fundamental expression of well understood physical laws. Perhaps you could explain what part of it you don’t find convincing.
Once we have covered this I’m happy to move on to Dr Hansen’s prediction but you might find a little independent research saves us all some time.
OK, let’s move on. Let’s say I now accept that the S-B law can prevent a rise that triples due to feedback (1°C per doubling becoming 3.3°C as per the IPCC).
Now let’s deal with Dr Hansen. Is he wrong? If so, why? He clearly does not believe that the S-B law prevents a runaway scenario.
Willis has an interesting article on WUWT related to the feedback issues discussed in this thread
http://wattsupwiththat.com/2011/08/14/its-not-about-feedback/