The Global Warming Challenge

Evidence-based forecasting for climate change

Archive for the ‘scientific approach’ Category

Inquiry into global temperature data integrity announced

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The London-based think-tank the Global Warming Policy Foundation  announced on 26 April 2015 a major inquiry into the integrity of the official global surface temperature records. Questions have been raised about the reliability of the surface temperature data and the extent to which apparent warming trends may be artefacts of adjustments made after the data are collected.

The inquiry will review the technical challenges in accurately measuring surface temperature, and will assess whether the adjustments to the data are biased and, if so, to what effect. For more information, or to make a submission, see here.

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April 27th, 2015 at 1:42 am

La Stampa interviews Armstrong on Gore bet

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The Italian newspaper La Stampa published an Alain Elkann Interview of Scott Armstrong on Sunday April 12 titled “J. Scott Armstrong: “Vi spiego perché le previsioni sul clima sono sbagliate”” here. Alain was particularly interested to know about the subject of Professor Armstrong’s challenge to Al Gore to bet that temperatures will increase dangerously, as Mr Gore has threatened will happen.

Regular readers of this blog will be familiar with the Challenge, but for those of you who are not, or who are interested to read a fresh summary of what scientific forecasting tells us about 21st Century temperatures, you can find the full interview in English on Alain Elkann’s own site here. For those of you who have friends who are struggling to make sense of the dangerous manmade global warming alarm, the interview is a good place to start.

New Book “Climate Change: The Facts 2014″

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The Institute of Public Affairs have published a collection of works on the physics, economics, and the politics of climate change (a.k.a. the alarm that dangerous manmade global warming is and will continue to occur.) The 21 chapters by leading researchers and commentators include Willie Soon’s “Sun shunned”, and Kesten Green and Scott Armstrong’s “Forecasting global climate change”. The book is available, here. We suggest sending Mr Gore a copy.

Update: Kindle versions of Climate Change: The Facts 2014 are now available on Amazon. Either search for the title or click the link to the book on your country’s Amazon site from the following list: US, UK, CA, AU, DE, FR, ES, IT, NL, JP, BR, MX, IN.

Environmentalist predictions gone wrong

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A small pleasure of the passing of time is that another batch of unscientific long-term predictions comes to full term and are exposed for what they always were: worthless. Fox News’s Maxim Lott has this New Year provided the service of reminding us of “Botched environmental predictions for 2015″. The first of the list is “UN overestimated global warming by 2015″. Another treat is “Arctic sea ice will disappear by 2015″. Maxim Lott’s article is available here.

There seems to be an endless supply of unscientific environmentalist alarms, as the Global Warming Analogies Forecasting Project has identified, here. Why? In part because forecasters of environmentalist catastrophes ignore the Golden Rule of Forecasting and assume that things are different now. In other words, they ignore cumulative knowledge about the situation they are making forecasts about, and about forecasting, in order to make extreme predictions. For more information on the Golden Rule of Forecasting, see If you don’t have the time to check out the Golden Rule, remember to treat forecasts of dramatic unprecedented changes in the same way you would treat last week’s newspaper horoscope.

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January 3rd, 2015 at 6:30 am

IUCN finds polar bear scientists’ models unsuitable for population prediction

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We imagine that Barbara Boxer will be particularly pleased that she did not respond to Professor Armstrong’s 2008 challenge to back her belief that the polar bear population was threatened with rapid decline by accepting his bet, based on scientific forecasting in Armstrong, Green, and Soon (2008), that polar bear numbers would remain at current levels or better.

It seems that modellers at the International Union for the Conservation of Nature agree with Armstrong, Green, and Soon that the models of polar bear biologist Steven Amstrup and colleagues, upon which Senator Boxer based her belief, are not fit for the purpose of forecasting the polar bear population. For more on this story see the article titled “Amstrup knows his polar bear predictions are flawed – but continues to promote them” on the site, here.

Are forecasts of a 2014 global temperature record believable?

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Based on NOAA figures for August 2014, Discover magazine posted an article online on September 19 with a headline making a dramatic forecast that, “With Summer’s Unequalled Warmth, 2014 is Likely to Finish as the Warmest Year on Record for the Home Planet“. AOL ran a piece on October 20 making the same forecast, this time backed with an extra month of NOAA data and the support of a claim by a NOAA scientist that “it’s pretty likely” that 2014 will see the global average temperature record broken… for the years since records began in 1880.

Climate scientist Roy Spencer begs to differ in his blog post titled “Why 2014 won’t be the warmest year on record“. Dr Spencer prefers the UAH satellite data record, pointing out that it, as opposed to NOAA’s adjusted and patchy thermometer data series, the satellite data provides a truly global and objective measure of temperatures. The Global Warming Challenge uses the UAH series as the measure for determining who will win the Armstrong-Gore bet for that reason.

We will post the outcome of the Spencer-NOAA conflicting forecasts when the data are finalised early in 2015.

Mr Gore’s tipping point forecast either biased, or very unlucky

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Since we started monitoring the Gore-Armstrong bet back in 2008, global mean temperatures have only rarely been as warm or warmer than Mr Gore and the IPCC’s +0.03 °C per year warming forecast would have had us believe. How rarely? Well, roughly one-month-in-five, or 21% of the 77 months to date. As we’ve pointed out before, one would expect the figure to be 50% if the Gore/IPCC forecasts were unbiased. Mr Gore must be very unlucky, because the chances that so few months would turn out to be as warm or warmer than unbiased forecasts is less than one-in-eight-million.

But wait, Mr Gore and the IPCC warned us that there was more chance that temperatures would be higher than their forecasts, than that they would be lower. In other words, they claimed their forecasts were biased toward slower warming than the rapid warming they really believed would occur. We haven’t calculated the vanishingly small odds that global temperatures would turn out to be so uninclined to warm taking into account the declared downward bias in their forecasts, but we suspect that Mr Gore and the IPCC have been feeling that the Earth has let them down.

For keen followers, the latest month of The Bet, May 2014, is shown in the chart on the right.

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June 16th, 2014 at 2:41 am

If “consensus” is evidence for alarm, what evidence its absence?

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Much has been made of the claim that there is an overwhelming consensus of scientific opinion that we will suffer dangerous manmade global warming during the 21st Century. Putting aside the unscientific and rather desparate nature of resorting to a vote to decide how the Earth’s climate will behave during the current century and beyond, is it true? In their Wall Street Journal op-ed of May 26, 2014, Joseph Bast and Roy Spencer examine the evidence, and shred the claim of consensus on dangerous warming in it various forms. Their op-ed is also available here.

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May 29th, 2014 at 5:05 am

March 2014 temperatures: More evidence on Gore warming bias

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The average global temperature for the first quarter of 2014 was less than 0.01°C different from Professor Armstrong’s no-trend forecast. With 75 months of data now in, we wondered whether there was any evidence of bias in Professor Armstrong’s or Al Gore’s forecasts. We found that there was. Both Armstrong’s and Gore’s forecasts appear to have a bias toward forecasting temperatures that are warmer than the measured temperatures. In the case of Scott Armstrong’s no-trend forecasts, they have to date averaged 0.02C warmer than the recorded temperature. In the case of Al Gore’s IPCC alarming warming forecasts, they have averaged 0.12C warmer. We think policy makers should prefer less-biased forecasts. The updated Climate Bet graph is to the right.

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April 10th, 2014 at 6:25 am

Armstrong and Green on climate models in NIPCC’s Climate Change Reconsidered II

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A summary of the critique of the use of complex mathematical models for forecasting long term climate change by Kesten Green, Scott Armstrong, and Willie Soon is published in the Nongovernmental Panel on Climate Change’s Climate Change Reconsidered II: Physical Science (2013).

The reference is as follows, and links to the relevant section and to the entire NIPCC report are available from the Global Warming Audit pages of the site, here.

Armstrong, J. S., & Green, K. C. (2013). Global climate models and their limitations: Model simulation and forecasting – Methods and principles. pp. 14-17 in Idso, C. D., Carter, R. M., & Singer, S. F. (Eds.), Climate Change Reconsidered II: Physical Science. Chicago, IL: The Heartland Institute.

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December 21st, 2013 at 11:32 pm