The Global Warming Challenge

Evidence-based forecasting for climate change

Archive for the ‘scientific approach’ Category

June 2015 temperatures edge up; remain below Gore line

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An up-tick in temperature anomalies in June saw Mr Gore and the warming scenario score the first win against the no-change forecast since January of 2013, nearly two-and-a-half years ago. The outlook for the dangerous warming scenario remains bleak, however. Over the 7.5 years of the Armstrong-Gore Bet so far—we have now past the ¾ mark—the errors that have arisen from projecting temperature to increase at a rate of 3°C per century are more than 50% larger than the errors from the no-change forecast.

Is it really possible that the simple no-change forecast of 21st Century temperatures is better than the IPCC projections from expensive and complex computer models? Yes, it is. That conclusion is consistent with the evidence presented by Kesten Green and Scott Armstrong in their recently published review of evidence on the effect of complexity on forecasting. They found that using complex methods increases forecast errors relative to the forecasts from simple methods that decision makers could understand by 27% on average. We expect that the results of The Climate Bet will increase that average.

For the latest data from UAH and the progress of the bet, see the new chart to the right.

Tenth International Conference on Climate Change

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The Heartland Institute’s Tenth International Conference on Climate Change (ICCC 10) took place in Washington D.C. on the 11th and 12th of June. Scott Armstrong presented a talk based on research with Kesten Green. Slides of their talk can be downloaded by clicking here. A flyer, summarising their evidence on climate forecasting, with links to relevant papers is available, here.

For this who missed the conference or would like to catch talks that they missed, videos of the ICCC 10 talks are now available online here. Scott gave his talk in a session with Anthony Watts and Roy Spencer. Video of their excellent session is here.

May 2015: Now 28 months straight of surprisingly low temperatures for Mr Gore

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While Mr Gore with his expectation of a “tipping point” and the IPCC with their dangerous warming projection will no doubt be surprised at how low global temperatures have been running, Professor Armstrong with his scientific forecast of no long-term trend in temperatures will not.

The Armstrong-Gore bet has now been running for 7 years and 5 months (89 months) now, and the average global temperature anomaly as calculated from satellite measurement by the UAH team has been 0.12°C. That figure compares with the 0.17°C average for the base year of the bet, 2007. That’s right, the average global temperature over the nearly 90 months since the beginning of the bet has been lower than the average for year the bet is based on.

The non-tipping point that we have been experiencing for more than seven years leaves Mr Gore’s bet out in the cold. His average absolute error to date is 0.22°C. That figure is 55% greater than the error of Professor Armstrong’s scientific forecasts. Yes, the scientific method does work, and can be relied upon ahead of the opinions of experts (even those of scientists) every time!

For the latest temperature data, click on the chart to the right of the screen.

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June 11th, 2015 at 3:02 am

Why is the Arctic ice still there, Mr Gore? Another failed prediction

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Al Gore predicted the Arctic ice cap would be gone by 2014 due to dangerous manmade global warming. The evidence is in: ice extent is up somewhat compared to the extent when satellite monitoring began in 1979. Professor Armstrong reminds readers of a May 20 article in The New American that there are no scientific forecasts that give credence to claims that dangerous global warming will occur. The article, titled “NASA’s own data discredits its predictions of Antarctic Doom”, is available here.

If Mr Gore really wants to make forecasts that are more accurate, he should learn the Golden Rule of Forecasting. By following the guidelines in the Golden Rule Checklist, he can avoid biased forecasting procedures that can cause forecasts to be less accurate than guessing. For more information on the Golden Rule, and to get a copy of the checklist of guidelines, see

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May 21st, 2015 at 4:47 am

Climate consensus? What climate consensus?

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An oft repeated climate forecasting claim is that 97% of scientists agree that there is a problem of dangerous manmade global warming and that human emissions of carbon dioxide must be drastically curtailed in order to avoid disastrous consequences. If that claim sounds unlikely to you, as well as being irrelevant, you are right. Professor Ross McKitrick—a scientific Toto to the climate-alarmist Wizard of Oz—dissects the claim and exposes its lack of substance in his May 11 article in the Financial Post titled, “The con in consensus“.

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May 17th, 2015 at 4:34 am

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.