The Global Warming Challenge

The Gore-Armstrong climate bet has now completed four-tenths of its ten-year race with Scott Armstrong in the lead. The latest graph and data are available to the right. Click on the graph to show a larger version of the graph with the data. You will see that we finished 2011 with average global temperatures for the year slightly lower than the bet benchmark year of 2007.

While Professor Armstrong is confident that his no-change forecasting method is better than Gore and the IPCC’s +0.03C per annum unscientific extrapolation, ten years is short in climate terms, and Mr Gore is still in with a chance. To provide some perspective, climatologists sometimes use seven years as the duration of a climate period. Over the last seven years, the UAH global temperature anomaly series has trended upwards at a rate of 0.008C per year. The solar magnetic activity cycle has a period of about 11 year. Over the last 11 years, the temperature series has had a trend of +0.019C per year. The former trend is much closer to Prof Armstrong’s no-change forecast than it is to Mr Gore’s extrapolation, but the latter is somewhat closer to Mr Gore’s extrapolation. The trend for the entire 33 year period of the UAH temperature series, at +0.0138C per annum, marginally favors Prof Armstrong’s forecasting method and suggests that there is no reason for alarm.

Theclimatebet.com will continue to report monthly results on The Climate Bet, assuming that Mr. Gore took the bet. Professor Armstrong maintains that changes in temperature are natural variations that occur over time. He expects the scientific approach to forecasting will win in the long-run, though he realizes the 10 years of the bet may not be long enough. When he proposed the bet, simulations of temperature changes over the previous 157 years indicated that his chances of winning would be somewhat greater than 62%.

An article by Kesten Green, Scott Armstrong, and Willie Soon in the International Journal of Forecasting explains the reasons behind Professor Armstrong’s choice of the no-change model for forecasting global average temperatures. It is available here.

With November’s temperature anomaly at 0.12, the Global mean temperature was below the 2007 benchmark for The Climate Bet, and Armstrong’s forecast, for a second month running. See the graph updated with November data on the right.

After three months of cooling, the global mean temperature anomaly for October was lower than the Climate Bet benchmark 2007 average. Atmospheric carbon dioxide levels have continued to rise.

We have now, belatedly, updated the Armstrong-Gore Bet Graph (to the right). The four month spell of increasing global temperature anomalies earlier in the year petered out and we have now had two months of global average temperature decline. Since the beginning of 2007, temperatures have declined relative to the previous month 52% of the time. The longest run has been 6 months of declining temperatures, while the longest run of increasing temperatures has been 4 months.

The last three months have seen a revival of Mr Gore’s hopes of winning the notional Climate Bet, with global mean temperatures more than 0.3 degrees Centigrade warmer than the 30-year average. We’ve seen higher, and lower, temperatures before in the  course of the bet however and, with more than six years to run and with the actual temperature close to Armstrong’s forecast for 25 out of the 43 months to date, the bet is still very much alive.

Global temperatures are back up to the level they were at the beginning of 2007… before they dropped below the 1981-2010 average for most of 2008. We don’t know where average temperatures (anomalies) will go next, but we do know that the Gore-Armstrong Bet is still very much alive.

We didn’t post this story at the time, but it is too good not to share more widely. On March 31, Scott Armstrong gave testimony to the U.S. Congressional Subcommittee on Energy and Environment on research to date on forecasting for the manmade global warming alarm. The event drew comment from New York Times columnist and Nobel Economics Laureate Paul Krugman on April 3. Professor Krugman made a play of finding it humorous that a leading expert on forecasting would be asked to testify on forecasting climate.

Our favorite quote from Krugman’s column is “… let’s talk a bit more about that list of witnesses, which raised the same question I and others have had about a number of committee hearings held since the G.O.P. retook control of the House — namely, where do they find these people?”

Perhaps Professor Krugman should get out more and meet some of the many scientists and the majority of voters who have realized that the dangerous manmade global warming alarm is simply not credible.

The New York Times published our letter of response on 10 April. Here is the text:

A Forecasting Expert Testifies About Climate Change

To the Editor:

In “The Truth, Still Inconvenient” (column, April 4), Paul Krugman begins with a “joke” about “an economist, a lawyer and a professor of marketing” walking into a room, in this case to testify at a Congressional hearing on climate science.

I am the marketing professor, and I was invited to testify because I am a forecasting expert. With Dr. Kesten C. Green and Dr. Willie Soon, I found that the global warming alarm is based on improper forecasting procedures. We developed a simple model that provides forecasts that are 12 times more accurate than warming-alarm forecasts for 90 to 100 years ahead.

We identified 26 analogous situations, such as the alarm over mercury in fish. Government actions were demanded in 25 situations and carried out in 23. None of the alarming forecasts were correct, none of the interventions were useful, and harm was caused in 20. Mr. Krugman challenged 2 of the 26 analogies, “acid rain and the ozone hole,” which he said “have been contained precisely thanks to environmental regulation.” We are waiting for his evidence.

“What’s the punch line?” he asked. I recommended an end to government financing for climate change research and to associated programs and regulations. And that’s no joke.

J. SCOTT ARMSTRONG

Philadelphia, April 6, 2011

The writer is a professor at the Wharton School, University of Pennsylvania.

After five months below the no-change forecast, temperatures have crossed the Al Gore forecast line. See the graph of actual temperature to June 2011 and the history of the bet with Scott Armstrong, to date, in the column on the right. Remember, you can click the graph to get a bigger image for closer inspection.

Global mean temperatures (more correctly, global mean temperature anomalies) for April and May 2011 have been added to our bet chart at top right. After three months at or below the 1981-2010 baseline, April and May were 0.12°C and 0.14°C above the baseline. Temperatures remained below the 2007 mean that Scott Armstrong offered to bet on, however, as they have done since the beginning of 2011. As a consequence, the errors to date from the forecasts that represent the pronouncements of Al Gore and the IPCC are in total 1.8% larger than those from the Armstrong forecasts.

As we have pointed out before, while Armstrong’s bet is based on evidence-based principles and Gore’s is not, 10 years is a short time period for bets about the climate and so the chance of a reversal are not much less than 50%.

In a response to environmentalist Bill McKibben’s assertion in the Washington Post that severe weather was becoming more common and more severe as a consequence of human CO2 emissions, Donald Boudreaux of GMU pointed out in the Wall Street Journal that there has been no clear trend in severe weather and, more importantly, deaths in the U.S. have declined in recent decades despite an increasing population.

Boudreaux argues that the trend of fewer deaths is consistent with economic theory and much evidence that people are creative and resourceful in market economies and that this creativity and resourcefulness drives adaptions that result in people living longer.

So confident is Boudreaux in extrapolating this trend, that he has offered to bet McKibben, or Al Gore or Paul Krugman, $10,000 that “the average annual number of Americans killed by these violent weather events from 2011 through 2030 will be lower than it was from 1991 through 2010″. Boudreaux’s WSJ column is here.