Tuesday, January 16, 2007

Frequency of record weather events shows randomness

Post below lifted from Lubos Motl

Charles Tye has pointed out the following article:
The subscription at physicsweb.org is free. Sidney Redner from Boston University and Mark Petersen from Los Alamos studied the question how frequently you expect record-breaking weather events to occur:
The qualitative lessons of their comprehensible work are not hard to swallow. If one assumes that a quantity - such as the temperature "anomaly" - is a random function of time without any autocorrelation and with an arbitrary fixed distribution, the probability of creating a new record will be dropping inversely proportionally with time. Why? If you have 78 random temperatures from the 13th of January of previous years, they are random uncorrelated numbers, by the assumption. The probability that the highest number in this set will be the new one from 2006 is simply equal to 1/79 because every competing day has the same chance. This decrease with time is called the inverse proportionality law.

However, if you have a long-term trend, a specific kind of autocorrelation, the decrease of the record weather events implied by the inverse proportionality law will stop. Instead, the rate of creating record events will approach a constant. If you have a wiggly curve that can however be approximated by an increasing linear function in the long term, it is clear that the numbers from the far past will have a low probability to be records. Only a smaller and fixed number of recent years will have a significant chance to compete as potential record-makers which will lead to an asymptotic time-independent probability of a new record.

On the other hand, the probability of a new record low temperature will go to zero in the presence of a warmind trend - faster than 1/T.

Redner and Petersen have looked at the data from Philadelphia - 126 years of data - and they found no statistically significant deviations from the inverse probability law i.e. no evidence of approaching a constant rate. As far as the frequency of measured record weather events in Philadelphia goes, there exists no climate change.

More recently, their best additional idea was to look at a city with a longer history and tradition than those of Philadelphia, namely Prague that offers records from the last 231 years. And they did find a signal in this case. Their (so far unpublished) analysis led them to the conclusion that it takes about 130 years for the rate of new records to approach a constant. The precise value of 130 years sounds a bit vague to me because the crossover from the inverse proportionality law to the constant regime is surely not sharp and discontinuous.

Nevertheless, you should believe that assuming the existing size of the trends, one needs more than one century of data to be able to recognize noise (weather) from a trend (climate change) in the frequency of record weather events. Equivalently, if someone cares about the "climate change" because it could increase the frequency of extreme events, the analysis shows that it can only do so measurably after more than a century. If someone predicts a huge amount of extreme weather events in 13 years, he seems to exceed the crackpot threshold by an order of magnitude.

Moreover, in 130 years, we may be able to measure a difference; a significant impact on our lives is a completely different level.

Their conclusion also allows us to disqualify all comparisons of record temperatures based on a 100-year timescale or shorter as noise or hysteria. Whoever uses these weather events to prove a long-term trend is a charlatan. The same conclusion, however, also implies that the same warming trend in Prague has existed before 1900 because the constant regime wouldn't be reached if the trend didn't exist before 1900: you need more than 130 years of the trend.

So it is unlikely that the bulk of the warming observed in the Prague data can be explained by the influence of the global industry that was negligible 100 years ago in comparison with its current size. Instead, the 19th century data from the Czech lands played an important role for them to reveal the underlying trend which means that according to their analysis, the bulk of the post-Little-Ice-Age warming should be of natural origin.


Air pollution is estimated to have killed nearly 10,000 people in Tehran over a one-year period, including 3,600 in a month, Iranian officials say. Most of the deaths were caused by heart attacks and respiratory illnesses brought on by smog, they said. The scale of the problem led one senior official to say living in the Iranian capital was like "collective suicide".

Cheap fuel encourages car use in Iran, correspondents say, and many vehicles do not meet global emissions standards. "It is a very serious and lethal crisis, a collective suicide," the director of Tehran's clean air committee, Mohammad Hadi Heydarzadeh, told an Iranian newspaper. "A real revolution is needed to resolve this problem." He said air quality had worsened and was linked to some 3,600 deaths in October. Many of the deaths were caused by heart attacks brought on by the air pollution.

New figures showed a sharp rise in pollution-related deaths in Iran, where 9,900 people died of pollution in the previous Iranian year (March 2005 to March 2006).




By Robert M. Carter, C. R. de Freitas, Indur M. Goklany, David Holland & Richard S. Lindzen


The Stern Review includes an introductory chapter that summarises the present state of climate science and, in Part II, an analysis of the physical and environmental impacts of prospective future paths of climate change. The credibility of the document as a whole thus rests in large part on how far the material presented under these two science headings is accurate and balanced.

Two distinct aspects are relevant here. First, there is the question of whether it can indeed be said, as the Review asserts in its opening sentence, that The scientific evidence is now overwhelming: climate change presents very serious global risks, and it demands an urgent global response. Second, there is the related issue of how far the Stern Review, in the sections that it devotes to them, gives an accurate account of the scientific issues. We consider that the Review is doubly deficient. The scientific evidence for dangerous change is, in fact, far from overwhelming, and the Review presents a picture of the scientific debate that is neither accurate nor objective. We present our argument under three main headings. In Section 1 we consider the Review's treatment of basic issues of climate science, and its over-confident conclusions about the prospective course of 'greenhouse gas' concentrations and global warming. In Section 2 we turn to what the Review says about the prospective impacts of the climate changes that it envisages as possible or likely.

Under both headings, we note two interrelated features of the Review: First, that it greatly understates the extent of uncertainty, for there are strict limits to what can be said with assurance about the evolution of complex systems that are not well understood. Second, that its treatment of sources and evidence is selective and biased. These twin features combine to make the Stern Review a vehicle for alarmism.

Section 3 is concerned with fundamental issues of scientific conduct and procedure that the Review fails to consider. Professional contributions to the climate change debate very largely take the form of published peer-reviewed articles and studies. It is widely assumed, in particular by governments and the Intergovernmental Panel on Climate Change (IPCC), that the peer review process provides a guarantee of quality and objectivity. This is not so. We note that the process as applied to climate science has tolerated gross failures in due disclosure and archiving, and that peer review is both too inbred and insufficiently thorough to serve any audit purpose, which we believe is now essential for science studies that are to be used to drive trillion-dollar policies.

Besides these three main sections and our summary conclusions in Part 4, we comment in an annex on some aspects of the mishandling of data in the Stern Review. Overall, our conclusion is that the Review is flawed to a degree that makes it unsuitable, if not unwise, for use in setting policy.


The alarmist view of climate science

Sir Nicholas Stern made a revealing comment in his OXONIA lecture of January 2006: "in August or July of last year, [he] had an idea what the greenhouse effect was but wasn't really sure". It seems that, starting from a position of little knowledge of the issues, he has swiftly espoused the official view of the Hadley Centre for Climate Prediction and Research, on whose advice the Review relies heavily.

But this Hadley Centre picture of reality, though broadly in line with that of the IPCC, is by no means universally held. Many of the specific claims that are endorsed in the Review have been seriously challenged in the scientific literature, while the text plays down the great uncertainties that remain. The Hadley message, as reflected in the Review, is an alarmist one. It presumes without question that moderate further increases in atmospheric CO2 levels will give rise to major climatic changes and that these are likely to be seriously damaging; that the climatic changes observed over recent decades can be reliably blamed on emissions of 'greenhouse gases' in general, and CO2 in particular; and that climate model projections and forecasts present a sufficiently accurate view of the future at relevant geographic and temporal scales to form a basis for major policy decisions.

The Stern Review itself fails to take proper account of the profound uncertainties and major gaps in knowledge of climate science, and neither does it address the many continuing debates regarding climate change mechanisms and impact assessments. Like its sources, the Review gives unwarranted credence to model projections over firmly established data and findings. By exaggerating climate alarm it focuses on implausible rather than likely outcomes, and thereby fails to provide a sound basis for policy.



We conclude that the Stern Review is biased and alarmist in its reading of the science. In particular, it displays:

* a failure to acknowledge the scope and scale of the knowledge gaps and uncertainties in climate science
* credulous acceptance of hypothetical, model-based explanations of the causality of climate phenomena
* massive overestimation of climate impacts through an implausible population scenario and one-sided treatment of the impacts literature, including reliance on agenda-driven advocacy documents
* lack of due diligence in evaluating many pivotal research studies despite the scandalous lack of disclosure of data and methods in these studies
* lack of concern for the defects and inadequacies of the peer review process as a guarantor of quality or truth.

These and other related problems arise because the Review has relied for advice almost exclusively on a small number of people and organizations that have a long history of unbalanced alarmism on the global warming issue. Most of the research cited by the Review does not, on inspection, make a convincing case that greenhouse warming constitutes a major threat that justifies an immediate and radical policy response. Contrary research is consistently ignored, as are basic observational facts showing that alarm is unwarranted. The Review fails to present an accurate picture of scientific understanding of climate change issues, and will reinforce ill-informed alarm about climate change among the general public, the bureaucracy and the body politic. HM Government will need to look elsewhere for a balanced, impartial and authoritative review of the current climate change debate.


By Ian Byatt, Ian Castles, Indur M. Goklany, David Henderson, Nigel Lawson, Ross McKitrick, Julian Morris, Alan Peacock, Colin Robinson and Robert Skidelsky


The starting point of the Stern Review is that 'The scientific evidence is now overwhelming: climate change is a serious global threat...'. For reasons that are set out in Part I above, we believe that this assertion is not correct, and that the Review's treatment of scientific issues is open to serious question. Here we go on to question its treatment of economic issues.

This is no straightforward task, because of the lack of clarity which characterises much of the Review's analysis. This has been noted by others: in the article of theirs that follows, and which likewise comments on the Review, Richard Tol and Gary Yohe make the point that 'It is impossible for a reader to understand precisely what is in the calculations that underlie' the Review; and in the same vein, William Nordhaus has written that 'It is virtually impossible for mortals outside the group that did the modelling to understand the detailed results of the Review'.

In an after-the-event attempt to clarify matters, a Postscript to the Review, accompanied by a Technical Annex on modelling issues, was published just before this article went to press. But much remains unclear, placing an undue burden on readers to excavate the actual structure of the Review's argument. Our treatment below falls under six headings.

We start in Section 1 by considering the Review's valuation of the possible impacts of global warming. Here our point of departure is Section 2 of Part I above, where our scientific colleagues have assessed what the Stern Review says about prospective biophysical impacts.

With their conclusions as a basis, we move on to consider, and to put in question, the figures that the Review derives for the prospective costs of these various impacts, and hence for the benefits that would supposedly flow from policies to reduce emissions.

From the projected benefits of mitigation, we turn in Section 2 to consider the prospective costs involved. We think that the Stern Review has understated these, probably by a wide margin. The combination of projected benefits that are pitched too high and projected costs that are pitched too low has led to a seriously unbalanced presentation of policy alternatives.

In Section 3, we consider the central issue of discounting the future. Here again we give reasons to question the Review's treatment. Critical issues are not fully explored, the bias towards immediate and far-reaching actions to reduce emissions is reinforced, and the risks and problems that would arise from following the Review's prescriptions for policy are not faced. Under all these headings, a recurrent theme is that the Review positions itself well outside the mainstream of published economic writings on these subjects: in relation to the professional debate, it appears as an outlier.

In Section 4, we consider the choice of policy instruments in the context of climate change, and comment on the treatment of these issues in the Review.

Section 5 deals with further major omissions from the Review-issues, and contributions to the subject, which the document fails to consider. Some of the points that we make here form a counterpart and extension of the argument in Section 3 of Part I above: we draw attention, as our scientific colleagues have done, to an established and officially approved process of inquiry which is not professionally up to the mark.

Section 6 summarises our conclusions. The Review shows serious weaknesses in its treatment and presentation of basic data. The Annex to Part I comments on one aspect of this failing, namely, the mishandling of basic observational data relating to climate change and the factors that bear on it. Here we present a counterpart annex of a similar kind. It deals with the Review's faulty handling of sources which are themselves flawed. The sources in question are the emissions scenarios which form the starting point for the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).



Our main conclusions coincide with, and serve to confirm and reinforce, those reached by our scientific colleagues in Part I above. Like them, we would emphasise in particular two interrelated features of the Stern Review:

* it greatly understates the extent of uncertainty as to possible developments, in highly complex systems that are not well understood, over a period of two centuries or more
* its treatment of sources and evidence is persistently selective and biased. These twin features have combined to make the Review a vehicle for speculative alarmism. We also endorse, from our own analysis, the judgement of our colleagues that the Review:
* mishandles data
* gives too little attention to actual observation and evidence, as distinct from the results of model-based exercises
* takes no account of the failures of due disclosure, and the chronic limitations of peer reviewing, that have been characteristic of work relating to climate change which governments have commissioned and drawn on.

As to specifically economic aspects, we have noted among other weaknesses that the Review:

* systematically overstates projected costs of climate change, partly though by no means wholly as a result of its failure to acknowledge the scope for long-term adaptation to possible global warming
* underestimates the likely cost-including to the world's poor-of the drastic global mitigation programme that it calls for
* proposes worldwide adoption of a specially low rate of interest for discounting the costs and benefits of mitigation, on the basis of inadequate analysis and without regard for the problems and risks that would result.

So far from being an authoritative guide to the economics of climate change, the Review is deeply flawed. It does not provide a basis for informed and responsible policies.

From "World Economics", Vol. 7, No. 4, October-December 2006. FULL PAPER here


Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is generally to promote themselves as wiser and better than everyone else, truth regardless.

Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists

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1 comment:

Anonymous said...


"Paradoxically, . . . the number of hot days
is increasing and the number of cold nights is increasing. We don't know how this latter statement fits with the phenomenon of global warming." -- S. Redner and Mark R. Petersen

My initial reaction is (a) INCREASED sun forcing by day, and (b) more efficient (INCREASED) radiation at night (due, perhaps to decreased cloud cover?). Actually, 'b' could account for both, couldn't it?

Has anyone looked at average cloud cover variations? Is this info., even likely to exist?

Of course, if this were contributing to the effect, I would think that it would probably not be good for the greenhouse gas theories. After all, the increase in temp., is supposed to be due to heat retention, which the increase in the number of record lows suggest isn't happening.