No cause for alarm at five-year mid-point of the Armstrong-Gore climate “bet”
By J. Scott Armstrong
In 2007, University of Pennsylvania Professor J. Scott Armstrong’s attention was drawn to former VP Gore’s concerns about global warming. Having spent five decades studying the science of forecasting, Armstrong decided to examine the basis for the forecasts of global warming. He was unable to find a single scientific forecast to support the claim that the Earth was becoming dangerously warmer or colder.
Instead, he found that some scientists were using improper forecasting methods to make forecasts. Professor Armstrong alerted Mr. Gore to this fact and suggested that they cooperate in a validation test of dangerous global warming forecasts. He suggested a 10-year bet for which he would forecast no long-term trend in climate, while Mr. Gore could chose forecasts from any climate model.
After a series of emails, Mr. Gore declined, apparently sticking with his claim that no time could be devoted to further study, because we were near a “tipping point,” a position backed by James Hansen of NASA. Professor Armstrong claimed that nothing new was happening, so there was neither cause for alarm nor need for government action.
Professor Armstrong nevertheless determined to pursue his proposed test of the alarmist forecast. By using the commonly adopted U.N. Intergovernmental Panel of Climate Change forecast—3°C of warming per century—to represent Mr. Gore’s position, the theclimatebet.com has tracked the Armstrong-Gore “bet” with monthly updates.
Mr. Gore should be pleased to find that his grave concerns about a “tipping point” have turned out to be unfounded. As shown on theclimatebet.com, Professor Armstrong’s forecasts have been more accurate than Mr. Gore’s for 40 of the 60 months to date and for four of the five years. In fact, the latest global temperature is exactly where it was at the beginning of the “bet.”
Professor Armstrong was not surprised. With some minor exceptions, his forecast was consistent with evidence-based forecasting principles. In contrast, the IPCC’s forecasting procedures have been found to violate 72 of the 89 relevant principles.
When he proposed the bet, Professor Armstrong expected to have a somewhat less than 70% chance of winning given the natural variation in global mean temperatures for a ten-year period. In light of the results to date, he expects an even better chance of winning, but as Yogi Berra said, “It’s not over till it’s over.” Furthermore, policy decisions will require validations testing for hundreds of years, not for just one decade. At the time of writing, there has been no trend in global mean temperatures for 16 years.
January 19, 2013