As Niels Bohr is reported to have said: “It’s hard to make predictions, especially about the future.” Yet we rely on all kinds of forecasts about all kinds of things to get an idea of what the future will be like. That’s not a bad thing – it’s better to have an informed guess than to have no idea at all – but we must always remember to calibrate our trust in these forecasts properly, and to go back once in a while to see how things actually turned outcompared to the original projection.
A lot of environmentalists get discouraged by gloomy predictions. Oh, in 2050 clean energy will only represent a tiny fraction of the total, they say. Electric cars will stay a small niche… Deforestation will be X hectares per year… Etc. But the reality is that forecasters are only human, and they have limited data and make mistakes (sometimes big ones), especially with things that involve exponential growth, or where a single tipping point can dramatically change things. Humans just aren’t very good at dealing with things that grow exponentially rather than linearly, and we can’t predict turning points very well.