The Global Warming Challenge

Evidence-based forecasting for climate change

Archive for the ‘kesten green’ Category

Who would win the ‘Climate Bet’, Al Gore or Scott Armstrong?

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In his talk on March 9, 2009 at the International Climate Change Conference in New York City, Wharton Professor J. Scott Armstrong will announce the launch of a prediction market on the outcome of the „Climate Bet‟ he proposed to Mr. Gore in 2007. Prediction markets are a structured scientific approach to eliciting and summarizing peoples‟ opinions. The Climate Bet prediction market is part of a project led by Andreas Graefe, a researcher at the Karlsruhe Institute of Technology (KIT) in Germany, to examine the use of prediction markets for controversial public policy issues. Are prediction markets useful in aiding the democratic process? Read the rest of this entry »

Written by mzfeldm

February 23, 2009 at 11:24 pm

Test Your Climate Change IQ

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Take this one-question quiz and see how well you can forecast global average temperatures (Available for download here) Read the rest of this entry »

Written by mzfeldm

February 19, 2009 at 9:48 pm

Uncertainty, the Precautionary Principle, and Climate Change

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The precautionary principle is a political principle, not a scientific one. The principle is used to urge the cessation or avoidance of a human activity in situations of uncertainty, just in case that activity might cause harm to human health or the natural environment. There is an interesting discussion of the history of the term in Wikipedia.

In practice, the precautionary principle is invoked when an interest group identifies an issue that can help it to achieve its objectives. If the interest group is successful in its efforts to raise fears about the issue, the application of the scientific method is rejected and a new orthodoxy is imposed. Government dictates follow. People who dissent from the orthodox view are vilified, ostracized, and may have their livelihoods taken away from them.

Consider the case of “climate change”. Warnings of dangerous manmade global warming from scientists, politicians, and celebrities have received much publicity. They admonish us to dramatically reduce emissions of CO2 in order to prevent disaster over the course of the 21st Century. Efforts have been made to stifle a scientific approach to the issue. In an article titled “Veteran climate scientist says ‘lock up the oil men’“, James Hanson, who heads the NASA Goddard Institute for Space Studies, was quoted as suggesting that those who promote the ideas of global warming skeptics should be “put on trial for high crimes against humanity.” The skeptics themselves have been ejected from, for example, State Climatologist positions and prevented from publishing research in mainstream journals, and they and their views are routinely attacked.

Much complexity and uncertainty surround climate change. The cumulative empirical evidence on proper forecasting procedures suggests that the most appropriate method in this case is naïve extrapolation. In simple terms, this means to forecast no change. Of course there will be change, but with current knowledge there is no more reason to expect warming than to expect cooling.

As we describe in our paper, we have been unable to find any forecast derived from evidence-based (scientific) forecasting methods that supports the contention that the world faces dangerous manmade global warming.

Appeals for urgent curtailment of human activity “just in case” are often couched in ways that imply that industrial societies are inherently sinful, rather than that there might be a problem to be dealt with. Indeed, interpretation of the precautionary principle is subjective and it is arguable that it is being misapplied to the issue of climate change.

Firstly, even if forecasts of increasing temperatures turned out to be accurate, predicted temperatures and other conditions are within the range of variations that have been experienced in the past. There is no evidence that the natural environment “prefers” relatively cool to relatively warm average temperatures. In fact, life in general prefers warmth.

Secondly, curtailing human activity would harm people’s health by making them poorer than they would otherwise have been. This is likely to be the case even if curtailing human activity happened to reduce global average temperatures. When the situation is framed in this way, the precautionary principle dictates that it is policies to curtail economically efficient human activity that should themselves be curtailed.

The outlook for the climate over the 21st Century is highly uncertain. There is a word in the English language to express high uncertainty. That word is “ignorance”. And ignorance is not a basis for responsible government action. We should expect our politicians to have the courage to resist interest groups’ calls for action in the face of ignorance.

The precautionary principle brings to mind the slogan on the Ministry of Truth building in George Orwell’s 1984: “Ignorance is Strength.” Instead of this political principle, we hope that politicians will turn to scientific principles for making public policy.

Written by mzfeldm

September 1, 2008 at 12:15 am

Skeptics Speak Out: Dr. Kesten Green

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The Competitive Enterprise Institute presented three videos by climate and forecasting specialists. Among the three are: Dr. Joseph D’Aleo, a former meteorology professor at Lyndon State College in Vermont and the first director of meteorology at The Weather Channel; Dr. Kesten Green, of the Business and Economics Forecasting Unit at Australia’s Monash University, and: Dr. Jim O’Brien, State Climatologist of Florida and director of the Center for Ocean Atmospheric Prediction Studies.

All three videos are available at GlobalWarming.Org. Kesten Green, adviser to this website, is featured below.

Kesten Green claims that the IPCC climate models incorporate just 15% of the principles and procedures appropriate to scientific forecasting. Many IPCC scientists seem to be unaware of forecasting methodology as a scientific discipline, he adds. Instead, the Monash University specialist charges that the models’ elaborate mathematical formulas reflect the IPCC staff’s own opinions at both the input and output stages.

One senior scientist and author with the IPCC ducks the charge of unscientific methodology, according to Green, by saying the UN climate models do not constitute forecasts or predictions. However, the specific words “forecast” and “prediction” reoccur many times in IPCC reports and they’re viewed that way by the public. If the IPCC in fact hasn’t made scientific forecasts, the Australian queries, what reason is there to be worried about climate change at all?

(From DOB Magazine Online)

Written by climatebet

April 29, 2008 at 10:37 pm

Polar bear fears groundless

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The U. S. government commissioned studies to support the listing of polar bears as a threatened or endangered species. Polar bear numbers are currently high and the population has been increasing rapidly in recent decades. Everyone likes polar bears, so this is good news. A decision to list would require forecasts that the current upward population trend will reverse. The government studies concluded that polar bear populations would decrease substantially.

Decision makers and the public should expect people who make forecasts to be familiar with the scientific principles of forecasting just as a patient expects his physician to be familiar with the procedures dictated by medical science. Three scientists, J. Scott Armstrong of the University of Pennsylvania, Kesten Green of Monash University, and Willie Soon of The Harvard-Smithsonian Center for Astrophysics, audited the government studies to assess whether they were consistent with forecasting principles. Their paper, “Polar Bear Population Forecasts: A Public-Policy Forecasting Audit,” has been accepted for publication in the management science journal Interfaces. It is the only peer-reviewed paper on polar bear population forecasting that has been accepted for publication in an academic journal.

They concluded that the government forecasts were based on false assumptions and their polar bear population forecasts contravened many principles for scientific forecasting. Indeed, the reports followed fewer than one-sixth of the relevant principles. Given the importance of the forecasts, all principles should be properly applied. In short, the government reports do not provide relevant information for this decision.

Research shows that for issues such as the population of polar bears—situations that are complex and where there is much uncertainty—the best forecast is that things will follow a “random walk;” in effect, this model states that the most recent value is the best forecast for all periods in the future. Because the polar bear population has been increasing over recent decades, however, a continuation of that trend over the short term is possible.

Copies of Armstrong, Green and Soon’s forthcoming paper are available at

Written by climatebet

March 31, 2008 at 6:25 pm

2008 International Conference on Climate Change: Green, Watts

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Track 2: Climatology (4:00-5:30pm)

Kesten C. Green, Ph.D.
Senior Research Fellow
Business and Economic Forecasting Unit
Monash University, Australia
Scientific Forecasting and Climate Change

In connection with J. Scott Armstrong’s earlier talk on polar bear population forecasting, Kesten Green focused broadly on the scientific forecasting of climate change, and the forecasting principles that should be applied to better forecasts. As shown in the audit of Chapter 8 of the 2007 IPCC report, the work repeatedly “contravenes” key forecasting principles that have been established over 70 years of forecasting work shown to improve forecasting. Perhaps the overarching principle as applied to climate change is that one should be conservative when uncertainty is high, or choose to the naïve no-change model as Armstrong has done in his Global Warming Challenge. Public policy should be based on scientific forecasting, and Green referred to Monckton’s words “we should have the courage to do nothing.”

Anthony Watts
Chief Meteorologist, KPAY-AM Radio
A Hands-On Study of Station Siting and Data Quality Issues for the United States Historical Climatology Network


Anthony Watts introduced to the audience his work on documenting the inconsistencies of surface stations across the United States and the world – the same surface stations that measure local temperature. A wide variety of issues plague these surface stations, from the changing of paint used to coat the outside, to surface stations being placed on roofs, near sewage treatment plants, next to cars and air conditioners. Only 12% of these surface stations recorded so far have been placed in areas that meet all the guidelines. With nearly half of all the surface stations already documented and listed on the site, the data from Watts’ work certainly puts the very measurement method under question.


Written by climatebet

March 7, 2008 at 5:52 am

2008 International Conference on Climate Change

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Kesten Green is giving a talk titled “Scientific Forecasting of Climate Change” at the 2008 International Conference on Climate Change, which is being held in New York City Marriott Marquis Times Square hotel from March 2 to 4. Sponsored by the Heartland Institute.

Global Warming: Crisis or Scam?

The debate over whether human activity is responsible for some or all of the modern warming, and then what to do if our presence on Earth is indeed affecting the global climate, has enormous consequences for everyone in virtually all parts of the globe. Proposals to drive down human greenhouse gas emissions by raising energy costs or imposing draconian caps could dramatically affect the quality of life of people in developed countries, and, due to globalization, the lives of people in less-developed countries too.

The global warming debate that the public and policymakers usually see is one-sided, dominated by government scientists and government organizations agenda-driven to find data that suggest a human impact on climate and to call for immediate government action, if only to fund their own continued research, but often to achieve political agendas entirely unrelated to the science of climate change. There is another side, but in recent years it has been denied a platform from which to speak.

The 2008 International Conference on Climate Change promises to be an exciting event and the point of departure for future conferences, publications, and educational campaigns to present both sides of this important topic.

Written by climatebet

February 27, 2008 at 7:45 pm

Posted in kesten green