The short answer is, most likely it is too late for Mr Gore to win the bet with Professor Armstrong. Here’s why…
Of the eight years of the bet so far, Professor Armstrong’s no-change forecast has been been more accurate than the Gore/IPCC “dangerous” warming forecast in seven. Looking at individual months, the no-change forecast has been more accurate for 72 of 96, or 75%. Overall, the errors of Mr Gore’s forecasts to date are nearly 42% larger.
To tip the balance of forecast errors back in Mr Gore’s favor, the temperature anomaly would need to average close to the Gore/IPCC +0.03ºC p.a. trend line shown in the updated chart to the right.
For those of you who arrived late or who would like a refresher, brief background to the Armstrong-Gore bet is provided at the link in the right column labelled “Challenge,” or here. (We recently extended the description of the background to the Challenge.)
October 2015 saw the warmest global average temperature for nearly three years at 0.43°C above the 1981-2010 average. November followed with an “anomaly” of 0.33°C.
The put the figures into the slightly longer term context of The Climate Bet’s nearly 8 years to-date, the first three months of 2010 were all warmer than the October just gone. But how consistent are the figures with the IPCC-Al Gore dangerous manmade global warming projection?
While the October figure on its own is consistent with the +3°C per century IPCC “business as usual” projection applied to the 2007 bet base year average—it was 0.02°C warmer—that has only happened in 14 of the 95, or 15%, of the months of the bet, to date. The chance that a warmer than projected temperature would happen so few times by chance with an unbiased forecast is one-in-1,612,577,151,852.
For an explanation of why the IPCC projections are such bad forecasts, see Kesten Green’s guest post “Is climate forecasting immune from Occam’s razor” on the Watts Up With That site, here.
The 93 months of the 120 month (10-year) Climate Bet so far has witnessed 45 months in which the global average temperature anomaly increased from the previous month, and 46 months in which the global temperature fell. This pattern, or lack of it, is of course consistent with the Green, Armstrong, and Soon (2009) evidence-based no-change forecast that is the basis of Professor Armstrong’s notional bet with Al Gore. For the latest data, click on the chart to the right.
You might be forgiven for wondering whether such a difference holds any meaning for you. Not only are the month-to-month and year-to-year variations in global average temperature tiny, the local temperature variations that you are experiencing are quite likely to be opposite in direction. For example, the UAH global temperature anomaly increased from 0.18°C in July to 0.28°C in August. Over Australia the anomaly average stayed the same at -0.22°C, and over the 48 contiguous U.S. states the average fell from 0.16°C to 0.09°C. Both Poles experienced below average temperatures in August of -0.10°C in the northern polar region and -0.61°C in the southern. And these broad regions are hardly local!
At 0.18°C, July’s global average temperature anomaly is very close to the 2007 average of 0.16°C that Scott Armstrong is betting is the better forecast than Mr Gore’s dangerous global warming “tipping point” forecast. The latest chart (click on the small chart image to the right) shows that temperatures have seesawed over the 91 months of the bet so far. An inspection of the vertical (temperature) axis indicates that the seesawing of the monthly global temperature anomaly has been rather gentle, barely exceeding a third of a degree either side of the 2007 annual average.
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.
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.
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.
The benchmark global temperature data from the researchers at UAH-Huntsville have been adjusted to compensate for drifting in the positions of the satellites that take the readings and other improvements in the measurements and calculations. The improvements in the data series must be disconcerting for warming alarmists such as Mr Gore and the IPCC: dangerous warming and a “turning point” are nowhere to be seen. We hope they are relieved that there is (even less) reason to believe the Earth is in danger and that governments will realise the folly of policies to reduce carbon dioxide levels.
Our chart of The Bet to April 2015 is shown to the right of the page, as usual, using UAH’s revised series. The picture is clear, but for this who prefer numbers, here is a very small one: 0.000000000005. That number (which is roughly equal to 1-divided-by 214 billion) is the probability that temperatures would have equaled-or-exceeded Mr Gore and the IPCC’s 0.03°C per annum warming projection as few or fewer times as the 13-out-of-88 months of The Bet so far that they have done so… if their projection were unbiased.
For more information on the UAH data revisions, see the description by Spencer, Christy and Braswell, here.
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 GoldenRuleofForecasting.com.