MEDEAS Project: The Next Step After the Paris Climate Agreement

By Ugo Bardi, Cassandra's legacy

Let me start with something to dispel the confusion about what models are for. When you deal with complex, adaptive systems, models are NOT meant to predict the future. As John Gall said in his book on complex systems, "systems always kick back" - to which I may add, "and sometimes they kick back with a vengeance". (another way to express this concept is "forecasting always fails.") But if dynamic models cannot predict the future, what are they good for? Simple, they are about being prepared for the future. Think of the Paris climate treaty of 2015. It was the result of millions of runs of various climate models, none of which claimed to predict "the" future. But these models are tools to prepare for the future; they tell you what may happen, depending on what you do. They are tools to shape political decisions. Out of all those runs,...