Mr. Armstrong vs Mr. Gore

Scott Armstrong of the Wharton School challenges Al Gore $20,000 that he will be able to make more accurate forecasts of annual mean temperatures than those that can be produced by climate models. Scott Armstrong’s forecasts will be based on the naive (no-change) model; that is, the forecasts would be the same as the most recent year prior to the forecasts.

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Environmental Forecasting and the Policy Process

There are many weaknesses in current climate models. Current models do not provide forecasts; they provide the modeler's own speculations or scenarios. Given the complexity and uncertainty involved, it is unlikely that these models will prove to be a useful guide. Scientific forecasts are derived from evidence-based models. To create a scientific forecast, several principles apply: it is important to avoid complex models and unaided expert judgment and to be conservative when uncertainty is high. In order to have an accurate forecast for global warming, there are several contingencies. First of all, there must be accurate forecasts in long-term temperature change, the effects of that change, and the effects of feasible policy changes. Climate modelers claim that their models are scenarios, not forecasts, but continue to refer to them as forecasts or predictions. Climate "experts" use models to present their own opinions and make adjustments to suit their assumptions. When making forecasts for complex and uncertain future events, experts have no advantage over nonexperts. Processing facts is most important.

After auditing the current climate change models, most of the forecasting principles were contravened, and there is not a single scientific forecast to support global warming. Forecasts by climate experts are of little value. Climate may change in the future, but because of the uncertainties that exist, the most sensible forecast right now is no change. To produce accurate results, modelers need to use scientific approaches to climate forecasts, avoid alternative sources of bias, consider alternative explanations, examine empirical evidence, use valid empirically based methods, provide full disclosure, present findings clearly, and obtain peer review.

Al Gore refuses to gamble on the environment