Dr Peter Stott is now head of climate monitoring and attribution at the UK Met Office Hadley Centre. He was in Hobart in mid-January for the IPCC’s WG1-AR5 fourth Lead Author Meeting, with 254 other scientists from 39 countries. They met to “consider comments received during the Expert and Government Review of the Second Order Draft”.
Stott: “You can’t say that a particular event - a particular heatwave or particular drought was definitely caused – or not caused – by climate change [ie: DACC, DAGW]. But what you can do is look at how the odds of events has changed. Is CC changing the odds, or making particular types of weather events more or less likely?”
ABC: You say event-attribution is an emerging science. How do you quantify how much is due to AGW as opposed to natural climate variability?
Stott: “You need to look very carefully at the observations. Then you need to use climate models to calculate the contribution which can be attributable to human influence, as opposed to natural variability. So what you are really trying to do is to detect the fingerprint of human influence and to distinguish it from other factors….
…What you are seeking to do is to compare the probability of having a heat-wave in a particular region as it exists at present with the probability we would have had if we had not changed the climate….
…It is also important to point out that not all of these EWEs will be shown to have had a significant contribution from climate change [ie: DAGW, DACC]. Many of them will, but some of them also will be attributed more to the natural variability of the climate.”
But can climate models ever determine accurately the AGW contribution attributable to human influence, as opposed to natural variability? Is there something fishy going on here? What is the probability that climate changes all by itself?
Stott: “What we have done in this brand-new report is to gather analyses; to have looked at some EWEs of the previous year and put them in the context of climate variability and change.”
Stott’s “brand-new report” — a research paper in the Bulletin of American Meteorological Society, Explaining Extreme Events of 2011 from a Climate Perspective — had received, he said, “a very, very positive response from the scientific community … the first example of near-real time attribution of a number of important extreme events occurring in one year.”
Stott did not mention the uncertainty monster during the interview, but he did admit that “to carry out such analyses and to make sure they are peer-reviewed and robust, this is really stretching the ability of the science and the scientists.”
His BAMS paper was more emphatic, stressing that “explaining the causes of specific extreme events in near-real time is severely stretching the current state of the science.” Nevertheless, he hoped this would the first of many annual EWE reports.
The IPCC, not surprisingly, agrees with him: “Extreme climate events can cause widespread damage and have been projected [not predicted] to become more frequent as the world warms”. But even it admitted last year that “it is often not clear which extremes matter the most, and how and why they are changing” (IPCC interdisciplinary workshop, 2012).
Another joint-authored paper — Attribution of Weather and Climate-related Extreme Events — presented to the 2011 World Climate Research Programme (WCRP) conference, gives a revealing glimpse inside the EWE sausage – and it sure ain’t pretty. Event attribution, we learn, is a very tricky business. Yet despite big challenges, such as whether “causal factors [for climate events and extremes] can be identified and model deficiencies addressed,” Stott insists that further ACE research “could lead to improved predictions of such events in the future.”
Attribution seems to come down to a dodgy three-way bet — and a loaded dice.
Here’s the bet: “Human influences have increased the risk of some extreme weather- and climate-related events, reduced the risk of others and, for some may not have affected the risk substantially”. Whatever the outcome, Team ACE can explain it away.
Here’s the dice: “A finding that human influence has not contributed substantially to the magnitude of a particular EWE may not be incompatible with a finding that human influences substantially altered the odds of such an event happening (especially a particular threshold exceedence).”
Heads I win, tails you lose.
Stott does admit, however, initial studies “highlight many of the challenges still to be faced”, the “considerable uncertainties that remain”, the uncertainty around alleged “causal links” and “whether relevant processes are captured adequately” by models.
One of them will be required reading in the “de-biasing” gulags proposed by pro-AGW social psychologists and purveyors of what might be called Lewandowsky Logic. It argues that “some cold events are consistent with the inter-play of on-going global warming and internal variability”.
A research group (Perlwitz et al) studied the “very cool 2008 climate conditions” in North America that “diverted strongly from the long-term warming trend observed over previous years”. Their “suite of model experiments” apparently “showed that an anthropogenic warming of North American temperature was overwhelmed by a particularly strong bout of naturally induced cooling resulting from the continent’s sensitivity to widespread coolness of the tropical and north-eastern Pacific sea surface temperatures.”
The study’s implications:
“…that the cool year in 2008 did not indicate that the climate was likely to embark upon a prolonged period of cooling and, on the contrary, the pace of North American warming was more likely to resume in coming years.”
As they say, go figure!
Stott’s concluding comments are also revealing: “While it is possible for an attribution service [such as ACE] to provide quantitative results, it is much harder to provide carefully validated results that include sufficient well-calibrated information that would enable a user to fully understand the capabilities and limitations of the information provided.” Needless to say, “in the interim it will be important to manage expectations."
In other words, don’t expect too much from us anytime soon.
Future “progress” apparently depends on – inter alia – “effective communication of attribution results, including remaining uncertainties”. Given we are told they are considerable, why do we rarely hear about them? It may be “effective” for ACE, but is it being economical with the truth?
No surprise, then, to discover even the UN-funded WCRP describes the quest for an atmospheric El Dorado – a “science underpinning the prediction and attribution of extreme events” – as a "Grand Challenge". Indeed, so much of a challenge that for David Karoly – who was at Team Ace’s foundation meeting four years ago in Boulder, Colorado – WCRP’s ambitious “climate information service” concept is only at "first draft" stage and still “needs consultation and feedback” from the CLIVAR, ETCCDI, GEWEX, WGSIP and WGCM model groups.
We learn something else from Karoly, too: there are “conceptual difficulties in validating model results against observations, first of all associated with (but not limited to) co-location in space and grid-cell data versus point measurements.”
Furthermore, any “improvements in longer term predictions of changes in the frequency and intensity of EWEs” will require “improved representation of key processes in climate models” and resolution of other complex issues.
When did the orthodoxy’s “authoritative” voice ever stress – or mention publicly – there are “conceptual difficulties” with the very models being used to determine EWE “probabilities”?
When did it reveal that “little is currently known about the predictability of the frequency of daily extremes at long lead times”? Does the political class know – or care – that “much work is needed to take careful account of uncertainty when delivering forecasts of extremes [EWEs] to users”? (Karoly, WGSP, 2012, white paper, I3).
When the word “mystery” appears in a peer-reviewed paper, it is time to sit up and pay attention. Did the 255 scientists in Hobart last month do so? Did they discuss the implications of this paper -The mystery of recent stratospheric temperature trends — during their one-week IPCC lead author meeting?
If not, they should; for it challenges the orthodoxy’s “settled science” mantra. As blogger Doug Hoffman explained here last month: Imagine part of the atmosphere
“that is literally only 10km from anywhere on Earth, a component of our environment that science thought it understood quite well. Now imagine the embarrassment when a major review in a noted journal finds that previous datasets associated with this component are wrong – and have been wrong for more than a quarter of a century. Yet that is precisely what has happened. The area is the stratosphere. The impact of this report is devastating for climate scientists and atmospheric modellers everywhere.”
Even worse, the paper’s authors concluded “the new data call into question our understanding of observed stratospheric temperature trends and our ability to test simulations of the stratospheric response to emissions of greenhouse gases and ozone-depleting substances.”
Seeking laws of climate-change and attribution? Prepare yourself for a long wait. Some (funded) studies can go on forever. How many climateers can dance on the head of a pin, or tango on the hot-plate of uncertainty? How many other “mysteries” are lurking in the belly of the catastrophist beast?
EWE attribution for some is like a magic pudding, delivering preferred outcomes in any situation. But for others, it is a stinking stew comprised of “X” parts of an atmospheric human fingerprint, “Y” parts of natural variability and “Z” parts of the orthodoxy’s secret ingredients; with X, Y and Z determined by the chef’s mood on the day (and availability of goat entrails for climatic devination).
Meanwhile, the fight for credibility is warming up, for the stakes have never been higher. EWE peer-reviewers are becoming more pugnacious and pugilistic. Some are throwing away their dice and putting on the gloves. Will there be a bare-knuckle brawl in the Year of the Snake – and AR5?
“Climate is what a boxer trains for, but weather throws the punches (D Arndt, 2012, Stott pers.com.). Attribution analyses have the potential to inform the necessary training and adaptation options for societies in dealing with the punches weather and climate extremes throw their way” (Stott et al, 2012, p13).
Expect, then, even more promotion – and politicisation – of speculative science, packaged as settled science. For climate researchers have convinced themselves – and their supporters – that the "Grand Challenge" of EWE predictability is achievable some day (soon), and are desperate to convince you. Hence the dodgy claims about “unprecedented accuracy” of model simulations and so on (Karoly, WCRP, 2012, white paper).
But for folk stunned “with irritation at the gaps and limitations still present” (Stott et al, 2012, p14), Team ACE and WCRP’s fantasy of creating an “authoritative attribution service” and “actionable [EWE] science” is an expensive folie de grandeur, a quixotic quest more appropriate in Swift’s Grand Academy of Lagado than our time. Perhaps they should join the professor working on a project for “extracting sunbeams out of cucumbers, to be put in phials hermetically sealed, and let out to warm the air in raw inclement summers”. Or share a lab with the learned gentleman researching a novel method for uncovering political conspiracies?
Professor Cucumber, motivated by an optimism almost comparable to that of folk who believe “while much work remains to be done in attribution science…..the ability to put recent EW or climate events into the long-term context of climate change should improve as each year goes by”; told Gulliver that “in eight years more, he should be able to supply the governor’s gardens with sunshine, at a reasonable rate.” The year was circa 1708.
WCRP’s research program also shines a light on the (lack of) knowledge base here. Despite the orthodoxy’s “authoritative” rhetoric, it needs to “develop better observational datasets, improve methodologies, make further progress in understanding [how] to assess and improve climate models”, and so on.
But models are the elephant in the room. As Professor G. Cornelis van Kooten explained recently in an essay, one “cannot base predictions on models that are not validated [against reality]. Yes, they contain well-known physical equations, but they also include a lot of ad hoc parameters and relationships based on weak empirical relations. Climate models are not validated, except against each other.”
Yet Team ACE has no choice but to use them to “calculate the contribution [“fingerprint”] which can be attributed to human influence as opposed to natural variability.” Has natural variability become merely an explanatory “sink” into which can be tossed any “odd stuff” left-over at the end of attribution process?
The big question, then – one the orthodoxy seems reluctant to ask itself, at least publicly – remains unanswered: Is this “human fingerprint” an artefact of the simulations used to “identify” it? Or is it a real phenomenon derived from, and detectable in, observed “patterns of global warming”? If the latter, where is the real-world empirical evidence for the alleged causal linkages?
As Judith Curry recently emphasised here: “on short time scales (decade to centuries), there is no satisfactory way of sorting out forced climate variability from natural internal climate variability unless you have a really good climate model that can adequately handle the natural internal variability on the range of time scales from years to millennia. Empirical methods have yet to do this in any sensible way…”
Furthermore, “until we better understand natural internal climate variability,
"we simply don’t know how to infer sensitivity to greenhouse gas forcing. The issue of how climate will change over the 21st century is highly uncertain.…Oversimplification and overconfidence on this topic have acted to the detriment of climate science. As scientists, we need to embrace the uncertainty, the complexity and the messy wickedness of the problem. We mislead policy makers with our oversimplifications and overconfidence.”
If the EWE-climate dice is loaded, it is loaded against the sceptical, the confused and the curious. They do not want more deception, more half-truths and speculation. They want clear and frank disclosure of the crucial uncertainties, of the “possible confounding factors”, of “the many scientific challenges to be faced in developing a robust assessment process for EWEs”, and so on.
How much longer will the activist climate change brigade and decarbonising elites be permitted to get away with so confidently dishing up misleading analogies, each-way bets, pseudo-predictions and dodgy attribution statements in a carefully choreographed semantic smokescreen designed to discourage criticism and public scrutiny?
When prognosticating about the planet’s weather-climate future, the voices claiming to be “authoritative” must come clean: more facts and less fiction, please.
© Michael Kile, February 2013
Disclosure Statement: The author does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. He has no relevant affiliations, except as author of the Devil’s Dictionary of Climate Change.