Climate change, to the best of our scientific knowledge, is happening, and much of the recent global warming that we have seen appears caused by human actions. And climate change is a significant problem that threatens heavy economic and social costs. The world that humans are creating—with an increased likelihood of more intense storms, prolonged droughts, and profound changes to ecological systems—is not likely to bring changes that people will want. These are some of the vital insights of environmental scientists like Paul Ehrlich. At the same time, predictions that “billions of us will die” by the end of the century as a result of climate change or that civilization will collapse reenact the least helpful elements of Ehrlich-style environmentalism. What often gets lost in the climate debate are the lessons of the clash between Paul Ehrlich and Julian Simon. There is a serious and significant discussion to be had over what policy actions to take, and when. How much will the impacts of climate change cost, and how urgent is the need for immediate action?

Sabin, Paul. The Bet: Paul Ehrlich, Julian Simon, and Our Gamble over Earth’s Future, 2014.

In poche parole, la mia previsione a lungo termine è questa: le condizioni materiali di vita continueranno a migliorare - indefinitivamente - per la maggior parte delle persone, nella maggior parte dei paesi, per la maggior parte del tempo. Nel giro di un secolo o due, tutti i paesi e gran parte dell’umanità conosceranno un tenore di vita pari o superiore a quello di cui godono oggi i paesi occidentali. Qualcosa mi dice, tuttavia, che anche allora molti continueranno a pensare e a dichiarare che le condizioni di vita stanno peggiorando.

Julian Simon, 1997
Citato in Meadows, Donella Hager. I nuovi limiti dello sviluppo: la salute del pianeta nel terzo millennio. Milano: Oscar Mondadori, 2006.

Meteorology, the science of the weather and of its prediction, has always been, both in the past and even more so in the present, the target of criticism and even jibes, the standard of its forecasting leaving much to be desired. In the words of one humorist among many, `Weather forecasting is a science which tells us about the weather we should have had !' (P. Bouvard). We can't really know what the weather will be like more than two or three days ahead, as many forecasters will confirm. But now, all this has been erased in a trice! Now, it is unhesitatingly claimed, we can predict weather and climate (which is the sum of weather) as far ahead as the year 2100, from our viewpoint a century earlier! Astrology or science?