The essence of science is testing predictions by comparison with real-world observations.

Al Gore and the IPCC have been saying for years that human emissions of CO2 would cause global warming at a rate of 3C per century. But IPCC’s forecasts violated 72 out of 89 relevant principles of scientific forecasting.

In 2007, Scott Armstrong, professor at the Wharton School and a specialist in forecasting methods, challenged Gore to a bet. They would track changes in global average temperature (GAT) according to satellite data and compare the Gore/IPCC forecast with Armstrong’s own forecast, which was for no change (the simplest forecast possible). After ten years, they’d compare the combined errors for each of the 120 months for each of the two forecasts. Whichever forecast deviated less from the observed GAT would be the winner. Gore rejected the challenge—which might tell us something about how confident he is of his claims. But Armstrong has kept track anyway.

Kestin “So how is the Global Warming Challenge progressing?” Here’s the answer:

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 passed 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.

The chart [above] presents the entire history of the bet, to date, and the table shows the latest three years of data from UAH, and the Armstrong and Gore forecast figures.

But then, who cares about real-world observations. Models rule?!

 

 

 

Featured image copied from “The Global Warming Challenge.”