Gore Refuses Global Warming Prediction Challenge

Published July 1, 2008

Al Gore, one of the world’s leading proponents of the theory that global warming is an imminent crisis, missed a deadline to meet a global warming challenge issued by a leading expert in forecasting.

Scott Armstrong, a professor at the Wharton School at the University of Pennsylvania, issued the challenge to the former vice president in June 2007. Gore initially indicated interest in the challenge, but later expressed some concerns.

Armstrong said he could forecast global temperature change over the next 10 years more accurately than any climate model Gore might nominate.

Armstrong’s forecast was to be that the global mean temperature would not change over the 10 years. His forecast is based on the so-called “naive model” that has been shown by prior research to be appropriate for complex situations with high uncertainty.

Armstrong proposed each man would put $10,000 into a charitable trust fund, and the one with the most accurate forecast would designate a recipient.

Backed Down Repeatedly

Gore indicated he was busy when the bet was first proposed, so Armstrong extended the deadline to March 26, 2008 and simplified the bet so Gore merely needed to put a checkmark beside a climate model that would produce forecasts for him. Gore then came back and said he did not believe in money wagers–so Armstrong proposed they forget the money and just conduct the challenge for scientific purposes.

Nothing more was heard from Gore, and the deadline passed.

On March 28, Armstrong sent a message to Gore, asking him, “When and under what conditions would you be willing to engage in a scientific test of your forecasts?”

Armstrong said, “Validation of forecasting methods is a key issue in climate change because, although we know that climate varies, we have been unable to locate a single scientific forecast that supports global warming. If Mr. Gore or anyone else is aware of such a forecast, they should reveal the source to the scientific community. Claims that science supports global warming forecasts have, to date, failed to provide sources.”

A history of Armstrong’s Global Warning Challenge to Gore is provided at http://theclimatebet.com. It includes all correspondence between Scott Armstrong and Al Gore.


Dan Miller ([email protected]) is executive vice president of The Heartland Institute.