Archive for the ‘j scott armstrong’ Category
After 2 months that saw wins for Professor Armstrong’s bet on no long term change in global mean temperatures, the UAH estimate for February came in at 0.35°C. That was 0.1°C cooler than Mr Gore’s “bet” on the IPCC 3°C per century warming scenario, but 0.2°C warmer than Professor Armstrong’s forecast.
While Mr Gore’s bet had a run of wins recently—from October 2015 to November 2016—Professor Armstrong’s scientific no-change forecast has won 80 of the 110 months of the bet so far. So, while Mr Gore’s favoured dangerous manmade global warming scenario is looking more credible than it has done for almost five years, the scenario’s cumulative absolute forecast error to date is still more than 22% larger than that of the no-change forecast.
The Climate Bet now has only 10 months of its 10 year term to run.
From a global average anomaly of 0.71°C for April, temperatures dropped to 0.34°C for June 2016, two months later. The fall in average temperatures of 0.37°C is the largest two-month decline in the history of the Armstrong-Gore Climate Bet, and closely matches the record two-month increase of 0.38°C that occurred between December 2015 and February of this year.
Despite the rapid cooling, June was still relatively warm, and so the month counts as a win for Mr Gore. He needs temperatures to pick up again rapidly, and stay well up, if he is to have a chance of winning the bet, which ends at the end of next year. For the latest data and chart, click on the small chart to the top right of the page.
Advocates of the dangerous manmade global warming hypothesis call for regulations in response to their alarm. Assume for a moment that the alarmists’ feverish scenarios really were going to come to pass… would regulations make the situation better?
The Iron Law of Regulation suggests otherwise. For a new site from Kesten Green and Scott Armstrong that is devoted to experimental evidence on the effects of regulations, see IronLawofRegulation.com.
While, after 99 months of the Climate Bet, Mr Gore’s forecast errors are 37% larger than Professor Armstrong’s, it is mathematically possible for Mr Gore to win. For that to happen, however, the global average temperature anomaly would have to stay around the average of the first three months of this year, +0.7°C. We will keep you posted!
We’ve had to adjust the Climate Bet chart to make room for the February 2016 UAH global average temperature anomaly of +0.83°C above the 1981-2010 average. For five months in a row now, Mr Gore and IPCC’s warming projection was more accurate than Professor Armstrong’s no-change-from-2007 forecast. The last time Mr Gore got such a run was in 2010, when the IPCC warming projection was more accurate for the first 10 months of the year.
Overall, however, the errors of IPPC projection are still as much as 40% larger than the errors from the evidence-based forecast of no change.
Mr Gore’s chances of winning the bet must, nevertheless, have improved with the latest figure. To put the data into perspective, if the temperature anomaly remained at or above .437°C for the last 22 months of The Bet—to the end of 2017—Mr Gore would win.
Perhaps Mr Gore will he change his mind and decide that he would like to put some of his own money at stake. He should be aware that the .437°C figure has only been equaled or beaten 7 times over the 98 months of The Global Warming Challenge to date, but that statistic will presumably carry little weight for those who, like Mr Gore, believe in the coming of a “tipping point”.
See the updated Climate Bet chart to the right.
In a recent (12 February 2016) article, Willie Soon, David Legates, and Christopher Monckton revisited the topic of measuring global temperatures and explained why satellite measurements are superior to terrestrial thermometer measures. For readers who would like a refresher on why it is that The Global Warming challenge adopted satellite temperature data as the criterion for judging the outcome of the Armstrong-Gore climate bet, see the Soon, Legates, and Monckton article “What do we know about CO2 and global atmospheric temperatures”, here.
The UAH global average temperature anomaly spiked in January to the warmest it has been during the 97 months of the bet so far. We have seen similar spikes earlier in the bet period, in early 2010 and January 2013. All three of those spikes were (just) more than 0.3°C warmer than the 2007 annual average, which is the base year of the bet and the no-change forecast that Scott Armstrong is betting on.
The three spikes amounted to 5 months in all of temperatures more than 0.3°C warmer than the 2007 annual average.
A glance at the updated chart (right) shows that there have also been downward spikes in the UAH global average temperature during the period of the bet. In fact there have been six cool spikes amounting to 8 months of temperatures more than 0.3°C cooler than the 2007 annual average.
Not only have warm spikes been less frequent than cool spikes, in the context of the bet the cool spikes have been relatively cooler than the warm spikes have been warm. The average cool-spike temperature was .02°C cooler than the 2007 annual average than the average warm-spike temperature was warmer.
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.)
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.
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.