Assessment of the reliability of climate predictions based on comparisons with historical time series by Koutsoyiannis et al. explore: “How well do the models capture the scaling behaviour of the real climate, by assessing standard deviation at different scales.” By their results they specifically throw down the gauntlet of “falsifiability” challenging IPCC to its very foundations. (Is it “scientific” or poltical.) Thought provoking on the role of science and verifiability in the public sphere. (Emphasis added) ———————
Abstract
As falsifiability is an essential element of science (Karl Popper), many have disputed the scientific basis of climatic predictions on the grounds that they are not falsifiable or verifiable at present. This critique arises from the argument that we need to wait several decades before we may know how reliable the predictions will be. However, elements of falsifiability already exist, given that many of the climatic model outputs contain time series for past periods. In particular, the models of the IPCC Third Assessment Report have projected future climate starting from 1990; thus, there is an 18?year period for which comparison of model outputs and reality is possible. In practice, the climatic model outputs are downscaled to finer spatial scales, and conclusions are drawn for the evolution of regional climates and hydrological regimes; thus, it is essential to make such comparisons on regional scales and point basis rather than on global or hemispheric scales. In this study, we have retrieved temperature and precipitation records, at least 100?year long, from a number of stations worldwide. We have also retrieved a number of climatic model outputs, extracted the time series for the grid points closest to each examined station, and produced a time series for the station location based on best linear estimation. Finally, to assess the reliability of model predictions, we have compared the historical with the model time series using several statistical indicators including long?term variability, from monthly to overyear (climatic) time scales. . . .
20. Conclusions
All examined long records demonstrate large overyear variability (long?term fluctuations) with no systematic signatures across the different locations/climates.
• GCMs generally reproduce the broad climatic behaviours at different geographical locations and the sequence of wet/dry or warm/cold periods on a mean monthly scale.
• However, model outputs at annual and climatic (30?year) scales are irrelevant with reality; also, they do not reproduce the natural overyear fluctuation and, generally,
underestimate the variance and the Hurst coefficient of the observed series; none of the models proves to be systematically better than the others.
• The huge negative values of coefficients of efficiency at those scales show that model predictions are much poorer that an elementary prediction based on the time average.
• This makes future climate projections not credible.
• The GCM outputs of AR4, as compared to those of TAR, are a regression in terms of the elements of falsifiability they provide, because most of the AR4 scenarios refer only
to the future, whereas TAR scenarios also included historical periods.
——————
European Geosciences Union General Assembly 2008
Vienna, Austria, 13?18 April 2008
Session IS23: Climatic and hydrological perspectives on long?term changes
——————
See also discussion at: ClimateAudit
The author is obviously a Global Warming Denialist!
Duvenoy:
More accurately, global warming has happened; there is little or no evidence than any warming has occurred since 1998, and little or no evidence that changes in climate before or after were substantially due to increases in atmospheric CO2.
The cited study would indicate CO2 levels have little or nothing to do with it.
See articles at ICECAP.us and “Global Warming and Nature’s Thermostat, Roy Spencer.
The question is not if anthropogenic climate change exists. The question is the magnitude, and even the sign (warming or cooling.)
The challenge is how to distinguish and quantify anthropogenic CO2 warming from major El Nino/La Nina and Pacific Decadal oscillations, and North/South oscillations, sun spot cycles etc.
The Relationship of the PDO to El Nino and La Nina Frequency
Ignoring a Natural Event to Blame Humans”John McLean October 2007
Trends in Pacific Decadal Oscillation Subjected To Solar Forcing” Dr Theodor Landscheidt
etc.
SCheeseman:
9 of the 10 hottest years on record have occurred within the last decade.
Of course, you could take the view that this increase along with the rapid increase in the release of gases from human activity are simply a coincidence. I can see how that view is highly desirable. Of course, you must then face the fact that none of the other posited causes for global warming (natural variation, changes in solar activity or volcanic eruptions) explain the data collected in the real world (http://www.timesonline.co.uk/t.....516033.ece) . Perhaps the warming is due to some mystical supernatural force? Perhaps it was intelligently designed!
“The cited study would indicate CO2 levels have little or nothing to do with it.”
[Duvenoy:] And yet the glaciers continue to retreat as do the polar ice caps. Go figger.
“In 2005 data from NASA’s Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide “ice caps” near Mars’s south pole had been diminishing for three summers in a row.”- National Geographic
“It’s not every day you get to watch a planetary ice cap vanish, but this month you can. All you need are clear skies, a backyard telescope, and a sky map leading to Mars.”- “Mars is Melting”, (science.nasa.gov)
Breaking: Warming On Jupiter, Mars, Pluto, Neptune’s Moon & Earth Linked to Increased Solar Activity, Scientists Say – Canada Free Press
Freemind: I repeat (wearily), there is no evidence that any warming has occurred since 1998. There is no contradiction in this and having several (not 9 in 10) of the hottest years in the last decade, or in have the ice caps continue to retreat. If a car stops accellerating, it continues moving at the same speed, right?
The same logic applies to retreating ice caps. Its warmer now. Sure. It was also warmer when the vikings landed in Greenland, but we had no measurements of arctic ice back then to worry about. The earth warms up and cools down. Read some of DLH’s links.
SCheeseman:
While the Climatic Research Institute’s figures do show 1998 as being the hottest year on record, NASA’s figures (which include polling stations in the Arctic unlike other surveyors) actually show it to be 2005. While 1998 was a freak (way out of pattern), overall trends show that the noughties have been significantly hotter than the nineties (here’s a graph http://www.ncdc.noaa.gov/img/c.....bar-pg.gif .)
I point out (wearily) that of course there are all types of complexities, freak results, exceptions, and feedback processes. But it takes a special kind of ignorance to be able to see past such an obvious overall trend. Climate scientists look at general patterns. Have you never taken a Geography lesson?
Of course your first position (it’s not any warmer) contradicts directly with your second point (it is warmer, but it’s all part of the natural pattern.) But what else should I expect? It’s a fallback argument constructed not for it’s truthfulness, but to prevent any action being taken:
1. Global Warming isn’t happening.
2. And even if it is, it’ll probably be beneficial
3. And even if it won’t, there’s nothing we can do about it, because it’s all part of a natural cycle entirely beyond our control
4. And even if it isn’t, it’s effect won’t be significant enough to justify the damage to our economy that any attempt to prevent it will cause
5. And even if it wont, there’s nothing we can do about it now, it’s too late. Now lets all go gas up the Hum-Vee and roll on the rapture.
Oh, and I was wrong. It’s only 8 out of 10 of the hottest years on record in the last 10. Boy, does that kill my argument!
Most studies suggest that this current increase can only be explained by taking into account human activity. But hey, we can’t trust all those science types with their academic persecution of dissent and liberal delusions. Pressure group spokesmen (paid for by our good friends at Exxon), scientists from un-related fields, scientists no-longer practicing, mavericks, and right-wing politicians are a much better measure of reality.
”A man hears what he wants to hear, and disregards the rest”
freemind
But do you support science sufficiently to look at the full range of data? Perhaps you might consider a global rather than US centric perspective. In particular compare NASA vs UK and Satellite evidence.
A tale of two thermometers
4 sources say “globally cooler” in the past 12 months WattsUpWith That January 2008
Note tomorrow’s presentation: Stephen McIntyre will present: “The Question of Global Warming: What do we really know?”
The warming trends just don’t seem to be holding up anymore.
DLH, add this one to your list:
ice cap levels
also, some newer satellite temps
satellite records
DLH:
I should point out that the Hadley figures still show the 8 hottest years on record all occurring within the last decade (they just differ on the order.) The overall trend still stands (see their graph here http://climateprogress.org/wp-.....hadley.gif .) The 1998 figure is explained by an exceptionally strong El Nino effect that year. 2005, in contrast, which NASA ranks as first and the Hadley Centre second in all time records, has no corresponding natural occurrence (from the Met Office’s own site http://www.metoffice.gov.uk/co.....ths/2.html .) Since La Nina has become more frequent again, (the cycle that brings cool water up from the deep Pacific, cooling global temperatures) the trend has become more gradual again.
As the Hadley Centre’s own release put it ”another way of looking at the warming trend is that 1999 was a similar year to 2007 as far as the cooling effects of El Nina are concerned. The 1999 global temperature was 0.26 degrees C above the 1961-1990 average, whereas 2007 was 0.41 degrees C above that average, 0.15 degrees C warmer than 1999.”
Another graph from the Met Office shows that the 17 warmest years on record have all occurred within the last 20 http://climateprogress.org/wp-.....adley2.gif , again showing the overall trend.
All this stuff about Greenland being green when the Vikings settled there should be treated with a huge dollop of skepticism. It was named thus by Erik the Red, an exile who wanted to attract followers to his new colony. It may well have been warmer when they arrived than when the colony collapsed, but it was never lush. The animals that they farmed had to be kept in barns for a full 24 hours a day, 7 days a week, for five months in every year.
Estimations of past temperature are based on numerous indicators, such as tree rings, corals, ice cores, sediments, boreholes, glaciers, etc. None of them are infallible. Again, it’s all about building up a general picture. The graph shown here (the lower one http://environment.newscientis.....-2_752.jpg ) shows the vast range of differing estimations for the past 1000 years. And yet all show an overall sharp upsurge within the last century. The warming we are seeing is unprecedented in recorded human history, and there are no obvious natural explanations like those we can provide for similar past events. The Greenhouse effect is scientifically proven. We know that Greenhouse Gases trap certain frequencies of radiation. We know that there has been a marked increase in certain Greenhouse gases within the last 150 years. We know this is attributable to human activity. We know that there is a precise match between the distribution of heat and the intensity of manmade emissions (see Tim P. Barnet et al., ‘Penetration of Human-induced Warming into the World’s Oceans’, Science, Vol. 309 (8 July 2005), pp. 284-7.)
Unless you want to appeal to some supernatural power or magic, then go figure.
Duvenoy (or whomever):
A couple of questions:
1) When you read about the increase in C02, it is always expressed as a percentage, “…C02 levels have increased by a staggering 27% in the last 150 years…” These alarmist pieces never mention that in actual quantities the increase has been from roughly 3 parts per 10,000 in the atmosphere to 4 parts per 10,000, for the obvious reason that no one could intuitively understand how such a minuscule increase in anything could have the dire consequences being attributed to it. Its a natural gas we exhale, that plants exhale, and increasing it by 1/10,000 in the atmosphere causes horrifying environmental consequences for all life? Look at a human body and how flexible it is in adjusting to all sorts of drastic, varying and harmful environmental factors – actual toxins, changes in oxygen level due to elevation, and a myriad array of stresses and assaults on our system which are all merely part of daily life. What other situation in nature can we point to where varying some naturally occurring compound by 1/10,000 results in catastrophe? So my first question is, an its an honest one, do you yourself intuitively understand or can explain clearly why varying C02 by this negligible amount will have the horrifying consequences attributed to it.
2) Just presuming that there is an actual causal link between the industrial age and changes in the planet’s temperature, what is the conceivable solution? It is always said that the temperature has been increasing steadily for the last 150 years. If human are to blame, what would decreasing industrial output by even say, 20% accomplish (which would take us back to what – 1980 levels?) So then you would be saying if we can just decrease the C02 by 1/50,000 that would help the planet A LOT. But wouldn’t a decrease in industrial output by even 20% equate to genocide – wouldn’t a few million people die directly as a result of such an action? The world population is seven times what it was in 1850. If we are to blame for the temperature rise, it seems only genocide would accomplish anything – actually decreasing world population by a couple of billion or so, at least.
These are the arguments of a layman, admittedly. I do actually think global warming is occurring (and after a certain point could certainly be harmful). I don’t think C02 or human activity has anything to do with it. Though I could be wrong.
OK I’ll modify what I just said. If its judgment from God then humans do have something to do with it. Maybe decreasing abortions, sexual promiscuity and drug use by 20% would help.
I’m an atmospheric scientist and I’ve mentioned on several occasions here that I have no faith whatsoever in the output of climate models. I work with numerical weather prediction (NWP) models on a daily basis. The IPCC itself says that GCMs are essentially the same as NWP models – just initialized differently (see “The Physical Sciences Basis”, Chapter 8, Climate Models and Their Evaluations, page 626). It appears to me that GCMs are actually simplified versions of operational NWP global models (e.g., GFS).
I am painfully aware of how poorly NWP models do at +7 days, to say nothing of decades in the future. The IPCC also admits that there are potentially large errors in model cloud projections (page 636).
Any outputs years/decades in the future from GCMs are virtually meaningless in my opinion.
LCM
Thanks – then you would appreciate even more Roy Spencer’s models:
Roy Spencer hypothesizes there is an “Internal Radiative Forcing” affecting climate variability. Internal Radiative Forcing And The Illusion Of A Sensitive Climate System,
Global Warming and Nature’s Thermostat” at WeatherQuestions.com
Upcoming publication:
Roy W. Spencer, “Evidence for Internal Radiative Forcing of Climate Change”. (In Review) April 19, 2008)
The warming due to the increase in CO2 is about 1F and is not controversial. The critical issue is whether that causes positive or negative feedback in the climate. All existing climate models assume a positive feedback multiplier. However, Spencer raises the critical issue of which is the cause and which the result. He has identified negative feedback mechanisms that had been assumed to be positive. He finds that cloud variability “noise” is not neutral. He has recently identified “internal radiative feedback” as possibly a critical element that is missing in current models.
SEA LEVEL RISE DISPROVED
My genius 12-year-old nephew has designed an experiment he says conclusively proves that sea levels would not rise “one bit even if all the ice at the North and South poles broke off into the sea and melted in two days.”
He applied the very complex scientific formula known as Archimedes Principle. He put a chunk of ice in a jug, and filled the jug up to the brim with salted water. As expected, about 90 per cent of the ice remained submerged.
He left the jug and its ‘iceberg’ at room temperature for about an hour until the ice melted.
He reported: “There was no water spill over, and that proves that polar ice, most of which is already in the sea causing displacement by volume, can not lead to a rise in sea levels once it melts.
“Water takes up more volume as ice than as liquid.”
He challenges anyone to try his experiment.
Emkay:
Your nephew is right, ice (because of it’s crystalline structure) does take up more space than water. If it was simply a case of ice floating in the sea, we would have nothing to worry about.
But that’s not the case with most of the Greenland ice sheet, or glaciers. We’re talking about run-off from the land. Similarly with much of the Antarctic ice sheet, we’re not just talking about ice bergs floating in the sea here. We’re talking about large land based ice sheets, which are held in place by sea based pack-ice. When that melts, there’s a real danger of whole chunks of the ice sheet becoming de-stabalised and sliding in, adding much more potential liquid to the equation. Your nephew’s experiment doesn’t seem to represent this very well.
Perhaps more appropriate would be if he balanced a huge meters thick sheet of ice at an angle on the edge of a tub of salt water, packing the top layer of the tub with ice to prevent the sheet from sliding in. I suppose the ice sheet would have to be on some sort of tilted funneled platform so that as it melted, the run-off would flow into the tub (which is what happens in the real case.)
If, after all the ice has melted, the level of the water still hasn’t risen, then :
1. I haven’t thought of all the things wrong with your experiment,
2. You didn’t do it right.
3. You(or your nephew) have made a discovery worthy of the nobel peace prize! After all, if that Al Gore douche can get one, you should be a shoe-in!
Emkay: Two more points to add to freemind’s, are: the physical expansion of the water due to the increased temperature, which would serve to increase the water’s overall volume, and thus increase the height; and the second affect, which is much smaller, is isostatic rebound. Areas losing ice tend to rise in elevation (as much of the northernmost part of North America continues to due since the melting of the continental ice sheets), while the oceans would tend to sink (VERY slightly, and VERY slowly) as the weight of water at any point on the ocean floor increased.
Finally; freemind, your sneering is barely disguised (point #3 above). Argue like an civlised adult or find some playground to push kids around in instead.
A small clarification to the above affect of water temperature on volume. The concern, of course, is that with global warming the entire ocean’s water volume would rise in temperature, not just the run-off from melting glaciers.
freemind, SCheesman: I showed the kid your comments. He wonders, since the supposed ‘global warming’ temperatures would be high enough to cause such massive melt, how much ocean evaporation would arise as a result of the same temperatures and neutralize the expected sea level rise?
SCheesman:
I apologise for seeming to be sneering. However, while I admit that the point was made with a certain degree of incredulity, it wasn’t meant viciously, and I think it wasstill valid. I would also point out ‘wearily’ that some of your own comments above could be interpreted as pretty damn snotty. Don’t preach what you can’t practice. I would also note that you have yet to respond to the points I made following that argument. Is Ad Hominem you preferred fall back?
Emkay:
That’s an interesting point. I think evaporation rates might well increase. But I think the time that the water spends in the atmosphere (as water vapour or clouds) would still be limited, so I can’t see it making that much difference overall. I think the more evaporation you get, the more rain, and so although the hydrological cycle might well be affected, you’d still get roughly the same amount of liquid back over a similar time period. I’m not sure about that though.
Also, temperatures wouldn’t have to rise so dramatically as to melt the ice totally. That’s something I should’ve factored into my above comment. It would be enough just to soften the pack ice keeping the whole thing up, allowing the ice sheet to slide in. This would lead to the rise in sea level, but the ice sheet needn’t necessarily be totally melted, as long as it was in the sea. It could be broken up, but not totally melted. Once the reflective surface of the sheet was reduced, a further feedback would follow, from greater ocean absorbtion of the sun’s rays. This would lead to greater warming, greater melting etc. But the temperature really doesn’t have to increase by that much.
See the new post:
Beneficial Natural Warming-31,000 Scientists
especially the related link to the technical review:
Environmental Effects of Increased Atmospheric Carbon Dioxide
See especially their very useful Powerpoint slides.
Emkay: freemind is correct, the amount of water the atmosphere can hold amounts to a few inches, and the incremental amount it would hold due to even a large temperature increase would be small in comparison to the rise in sea level due to increased temperatures, so as a “negative feedback” it is not really effective.
Freemind: Ad hominems and snottiness are not generally my style. If you did not intend snottiness, I am happy to let it go. I do not believe I ever used an ad hominem, and if my “wearily” appeared intemperate, I apologise.
As for responding to the points you raised, was it this one:
I would say no. I expect cosmic ray flux and its affects on cloud formation are the primary factors. So mystical, perhaps yes, but supernatural, no. Intelligently designed, undoubtedly!
Do I deny that CO2 has any role? Of course not. With DLH, I expect it might contribute up to a degree F, but expect that negative feedbacks are operative, including the iris effect in cloud cover.
As for the 9/10 vs 8/10, after I submitted my remark, I thought, after looking at the graph (by gosh, I think it is 9/10), so thank-you for setting me straight about it being 8/10!
DLH: Great Powerpoint!
SCheesman:
Nope, I was rather referring to the stuff in the later post about the trend of warming since 1998 (and explanations for it.)
In terms of Cosmic Ray Flux, one of the more interesting Denialist arguments, I will concede that it’s possible (however speculative) that Cosmic Ray intensity can influence cloud cover, and therefore temperature to some small degree. But it just can’t explain the warming trend of the last few decades. Direct measurements of Cosmic Ray Intensity over the last 50 years show no downward trend coinciding with the recent warming. While indirect measurements of Cosmic Rays (based on the atmospheric isotopes they form) suggest that intensity fell between 1900 and 1950, a lag between a sudden jump in a climate ‘forcing’ and it’s full effects on temperature shouldn’t be longer than a few years, and the effects on temperature of such a jump would’ve tapered off long ago (rather than growing more extreme.)
Regarding the Iris Hypothesis, I see no reason to put any trust in it whatsoever. Considering the only evidence in it’s favour seem to be Spencers’ papers, and Spencers’ past record on interpreting data, it seems like speculative wishful thinking to me. Even if it is proven to be true, I see no reason to attribute to it the significance some do.