This year’s election demonstrated very clearly that forecasting is fraught with dangers because it is dependent on assumptions, the quality of data, and the structure of models used. And, the lessons from the failure of most pollsters/forecasters to come close to the actual election results should lead modelers and users of model outputs, independent of the field of study, to show a bit more humility. That is especially true about climate and other environmental models.
For almost three decades, climate models have over predicted the affect of greenhouse gases on global temperatures and weather events. That should surprise no one because the climate system is complex, chaotic, and still not well understood. It should be obvious that if the system being modeled is complex, not well understood and requires a very large number of equations, the models built to represent it cannot be accurate, especially when the forecasters use point estimates instead of ranges that reflect uncertainty. That has been the case with climate models and the forecasts that come from them,in spite of the billions of dollars spent on model development and the super computers to run them.
In spite of a very poor records of predictions, those who make predictions based on these complex models are considered experts who must be listened to. In fact, the cult of climate experts who peddle visions of doom are no better that fortune tellers and seers of the Middle Ages who became well knows by their prophecies of the future. Assertions of expertise is no substitute for being right more than half the time.
Whether forecasting economic growth, elections, or future climates, forecasts are no better than the understanding of the underlying phenomena, the data that reflect those phenomena, and the models that process that data. The uncertainties in our understanding of the climate system as documented by the IPCC should disqualify climate models from being used to drive policy.
Professor John Christy in congressional testimony presented a comparison of a large number of models with actual temperature increases over the past few decades. While that is a short time frame for climate, all of the models over predicted actual temperatures. That fact is evidence of a bias about how the climate system is thought to work and a lack of humility about the inability to model a complex and chaotic system. Instead of expressing humility, climate advocates double down by making their models more complex and providing rationalizations for their inaccurate forecasts. Unfortunately, the political system hasn’t discounted the forecasts, it has embraced them, wasting money on solutions to a contrived problem.
A new Congress and new Administration has the opportunity to change course and demand a higher level of objectivity and real scientific proof.