The Global Warming Challenge

Evidence-based forecasting for climate change

Archive for the ‘forecasting’ Category

Who is more accurate, the global coolers or the global warmers?

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Kesten Green and Scott Armstrong tested the predictive validity of the United Nations’ IPCC global warming hypothesis of +0.03°C per year due to increasing CO2 against the relatively conservative hypothesis of natural global cooling at a rate of -0.01°C per year. The errors of forecasts from the global warming hypothesis for horizons 11 to 100 years ahead over the period 1851 to 1975 were nearly four times larger than those from the global cooling hypothesis.

Forecasts from the no-change model, however, were substantially more accurate again than those from the global cooling hypothesis. Findings from their tests covering a period of nearly 2,000 years support the predictive validity of the no-change hypothesis for horizons from one year to centuries ahead (Green and Armstrong, 2014). A pre-publication draft of their “Forecasting global climate change” chapter is available, here.

Reference
Green, K. C. & Armstrong, J. S. (2014). Forecasting global climate change. In Moran, Alan (ed.). Climate Change: The Facts 2014, pages 170-186. Published by the Institute of Public Affairs, Melbourne, Victoria 3000, Australia.

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January 28th, 2015 at 3:02 am

Global temperatures: Seven years of Sideways

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It may be hard to believe with the rhetorical bombardment of the warming alarmists and their supporters in the media that we are exposed to, but global average temperatures over the last seven years averaged less than the 2007 base year of the Armstrong-Gore bet. Yes, you did just read that!

The average of the monthly temperature anomalies in 2007—as calculated by the University of Alabama at Huntsville scientists from satellite observations—was 0.21°C. The average for the seven years since then was 0.20°C.

That doesn’t seem like a tipping point, Mr Gore!

The updated graph, to the right, shows not a tipping point, but lots of turning points. The net result? You guessed it, a sideways drift that is just what followers of this site and the evidence-based Green, Armstrong, and Soon no-trend forecast would expect.

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January 16th, 2015 at 12:03 am

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 Amazon.com 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 goldenruleofforecasting.com. 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 Amstrad 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 polarbearscience.com site, here.

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December 7th, 2014 at 12:05 pm

With November data in, 2014 looks warmer than 2013, but much cooler than 2010

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Looking only at the nearly 7 years of The Climate Bet, with one month of 2014 to go any talk of record warmth looks to be a big stretch. For the average temperature anomaly for 2014 to exceed the relatively warm 2010 average,  December’s anomaly would need to come in at an unprecedented 2°C or higher. We think Mr Gore and the IPCC should not count their chickens before they’ve hatched. For the latest graph and numbers on the Bet, see the updated chart to the right.

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December 6th, 2014 at 7:02 am

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.

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October 27th, 2014 at 2:31 am

August 2014 fails to warm

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We’ve updated the Climate Bet graph on the right with the global average temperature for August. The picture seems clear to us: there is no trend. Not surprisingly then, the projected 0.03°C per year increase that the IPCC and Mr Gore (who expected a tipping point and dangerously warming temperatures) thought was likely on the low side has been equaled or exceeded only sixteen times in the 80 month life of the bet, so far. In contrast, monthly temperatures have come in lower than Professor Armstrong’s bet on no-change for 55% of months.

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September 9th, 2014 at 4:47 am

July temperatures sideways as Gore error trajectory continues upwards

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For 21 months straight, global mean temperatures have been below the 3°C per century increase projected by the IPCC, and Mr Gore’s forecast turning point is nowhere to be seen. We wonder whether Mr Gore’s investment predictions in his August 6 op-ed in the London Financial Times are of the same caliber. For the latest temperature data and progress on the Climate Bet, see the updated chart to the right.

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August 16th, 2014 at 2:33 pm

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