Abstract
These empirical results suggest that overly pessimistic predictions of global warming precede large falls in global temperature. Thus, the level of alarmist sentiment has the potential to be a useful predictor of global temperatures. The rational null expectations hypothesis is tested against the alternative hypothesis that extremes of sentiment signal turning points in global temperature.
Introduction
Sentiment models are based on the idea that extreme sentiment levels signal turning points. These points occur at rare times, when irrational emotional responses lead to temporary extremes that are unsustainable. If you are indeed near the peak of an extreme, it is more likely that levels will fall away, thus contradicting the extremes up to and at the peak. Being aware of sentiment models can help you identify when levels of sentiment are at unrealistic, alarmist extremes.
The figure below shows the correspondence between landmark studies in global warming in the last 10 years and sudden falls in global temperatures. The first and largest fall was after the publication in 1998 by Mann et al. of the (now discredited) Hockey Stick showing temperatures flat for the last 1000 years and suddenly spiking up in the 20th century. The start of the most recent fall in temperature coincides with the 4 May 2007 publication by Rahmstorf et al. (Science Brevia) concluding that “The climate may be responding faster than IPCC models suggest”. The onset of other major falls in the last ten years is marked by other landmark studies in climate alarmism. The publications numbered in the figure are listed below.
Figure: Dates of publications indicating extremes of global warming sentiment precede sudden falls in global temperature (UAH MSU for lower troposphere).
1. April 1998 Paleoclimatology
“Global-scale temperature patterns and climate forcing over the past six centuries“, by Michael E. Mann, Raymond S. Bradley & Malcolm K. Hughes. The origin of the famous hockey stick graph claiming temperatures are the highest experienced in 600 (and then 1000) years. The view has been reversed by a number of more rigorous studies.
2. January 2004 Biodiversity
“Extinction Risk from Climate Change,” by Chris D. Thomas, Alison Cameron, Rhys E. Green, Michel Bakkenes, Linda J. Beaumont, Yvonne C. Collingham, Barend F. N. Erasmus, Marinez Ferreira de Siqueira, Alan Grainger, Lee Hannah, Lesley Hughes, Brian Huntley, Albert S. van Jaarsveld, Guy F. Midgley, Lera Miles, Miguel A. Ortega-Huerta, A. Townsend Peterson, Oliver L. Phillips8 & Stephen E. Williams, Nature, stating “we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15–37% of species in our sample of regions and taxa will be ‘committed to extinction’.”
2004 has been described as the year global warming got respect. A number of significant reports of alarmist sentiment appeared throughout the year (as temperatures plummeted) including the Climate Impact Assessment (ACIA) report by an international team of 300 researchers for the Arctic Council, predicting the Arctic will lose 50% to 60% of its ice distribution (ice extent has since returned to long term averages). In December “The Scientific Consensus on Climate Change” by Nancy Oreskes found of papers published between 1993 and 2003 with the words “global climate change” in their abstracts that “Not one of the papers refuted the claim that human activities are affecting Earth’s climate”.
3. May 2006 Hollywood
The movie An Inconvenient Truth by Al Gore released
(soon as an opera).
4. May 2007 Global Climate Models
“Recent Climate Observations Compared to Projections” by Stefan Rahmstorf, Anny Cazenave, John A. Church, James E. Hansen, Ralph F. Keeling, David E. Parker, and Richard C. J. Somerville expressed the view that the IPCC (the consensus view on climate change) was too conservative and that “The climate may be responding faster than our current generation of models suggest” (temperatures have plummeted once again).
Results
With a rational expectation of no bias, publications marking extremes of sentiment would be correct half of the time. The probability of the four publications would precede large falls in temperatures is 0.5×0.5×0.5×0.5=0.0625 or 6.25%. The null hypothesis is thus rejected at the 90% level but not at the 95% level. It is thus ‘very likely’ (according to IPCC terminology) that extremes of global warming sentiment mark turning points in global temperatures. Further work on development of an index of extreme global warming sentiment is in progress, and would be an important contribution to the emerging science of global warming error theory.
24 responses so far ↓
sorry, but the column with “recent pots, “links2, et. covers half uour graph…
OK I scaled it down. Is that better?
Looks OK to me now.
Fascinating hypothesis, David. Skeptics might query the causality (do the papers you cite precede or follow the temperature peaks?) But that quibble aside (who cares about the physics when we have a confidence interval to admire?), I note that there is marked variation in the amplitude of the reversals with the famous ‘Gore gulf’ being the smallest, using the OET (ordinary eyeball test). Is this significant? Could there be another factor lurking under the surface here? Total lunar irradiation (TLI), for example?
Thats a very interesting suggestion for further refinement of the model Peter, which I shall acknowledge on submission to the Annals of Improbable Research.
I believe the Gore Gulf may be caused by the Plausibility Factor. The lower the Plausibility of the “author”, the smaller the effect.
Peter G,
if there are questions as to whether the data fits the model, we must adjust the data!!
You mean the gods are playing tricks on us! But what’s the mechanism? Is Nature reading Nature?
But what’s the mechanism?
Perhaps a malicious error model instead of random errors.
Nice observation, David. I have also similar thoughts. Several expert forecasters in Greece predict often catastrophic events for the next season, year etc. As usually the opposite happens, I get anxious when they do not predict catastrophes.
As a good friend has put it, “I sometimes wonder if Mother Nature takes a small-minded pleasure in humbling over-confident scientists.”
I have learnt from sad experience the eternal truth that pride goeth before a fall.
Wow…..four very powerful correlations there, although I’m not absolutely sure that a correlation is proof…..but four in a row, that’s strong; wow!
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Re #9. I’m worried, Hadley et club, in previous years have made a succession of public forecasts that the coming year(s) individually will be the hottest ever……something like that.
They did not forecast doom for 2008 though. Oh dear, this ain’t like Greece is it?
#11, OK, so where are the statistics wrong here?
Re #10
David, the Greek version of “pride goeth before a fall” has the word
“hubris” instead of “pride” (I found it in the Bible, Proverbs, 16,
http://nasb.scripturetext.com/proverbs/16.htm — and the Greek version
in http://sepd.biblos.com/proverbs/16.htm). Perhaps the Greek word
“hubris” (explained in http://en.wikipedia.org/wiki/Hubris) better
describes the state of our current civilization (overexploitation of
environment and natural resources, primarily energy, to cover our
inflating consumer needs) as well as the state of science
(over-confidence in “ability” to predict what will happen in 100 years).
In Greek tragedy, hubris is followed by nemesis (destruction), as in the
Bible.
Quoting Heraclitus, “To extinguish hubris is more needed than to
extinguish a fire”.
Demetris, that is a good writeup about ‘hubris’ from wikipedia, and is probably a much better translation than pride. It describes the disregard for the basic mores of science and statistics that I see in the most alarmist manuscripts. Steve McIntyre’s criticisms of ‘the team’ could be attributed to the teams hubris.
BTW this is getting OT but what is the Greek translations of ‘vanity’ in Ecclesiastes?
Re #14. The Greek for ‘vanity’ is ‘ματαιότης’ (’mataiotes’; but I do not think it exists in English).
Could mataiotes possibly be related to ‘empty’?
Hi David,
“Could mataiotes possibly be related to ‘empty’?”
If taken from Ecclesiastes it’s quite likely the Hebrew is ‘havel’ (Hey beit lamed) vapour or breath perhaps also void (infintive ‘hevel’ = to make void) It’s also the name of Adam and Eve’s second son.
I’m still thinking about where the statistics are wrong but suspect that the probability of climate going up or down at any given time might not be precisely .5 since the wiggles are always going to happen but I’m guessing.
Are you cherry-picking your data? It seems to me that a major alarmist study is announced about once a week, year-in, year-out. Oh, that’s your point, isn’t it?
[...] Bonus: Global warming hype causes global cooling. Posted at 6:57 AM | | [...]
The Hockey Stick publication seems to have had the largest effect. Sort of like Pinatubo or maybe even Krakatoa. Oddly, An Inconvenient Truth had a lesser effect. But who knows what an opera could do.
Lucia,
I don’t think Stefan Rahmstorf’s drop has quite finished yet we might have to wait and see.
I like that. It shall refer to it as Rahmstorf’s drop from now on.
@22 Rahmsdropf ?
[...] I made a submission, along with 4000 others, summarizing the sensitivity testing and conversations with Rahmstorf over a one page article published in science, claiming that the climate was responding at a faster rate than the climate models predict. It turned out the article was eerily prescient, marking the start of an over 12 month decline in global temperatures dubbed ‘Rahmstorf’s drop‘. I think it is supposed to be getting warmer, not colder. We looked at this article in detail here. In a series of exchanges with Rahmstorf documented here, it was apparent that the uncertainty was too large to support the claims made by Rahmstorf et al. 2007, and that he had no idea of how the dubious, ad hoc end-point smoothing procedure worked. Despite its obvious severe limitations, Ramstorf et al. 2007 was the sole basis for the previous Garnaut report’s concern that climate change was an urgent problem that must be hastily addressed. It will be interesting to see how he thinks climate change will affect the Australian economy, if Rahmstorf’s drop continues to bring lower global temperatures. [...]
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