COPENHAGEN — Have you noticed how environmental campaigners almost inevitably say that not only is global warming happening, but that what we are seeing is even worse than expected?
This is odd, because any reasonable understanding of how science proceeds would expect that, as we refine our knowledge, we find that things are sometimes worse and sometimes better than we expected, and that the most likely distribution would be about 50-50. Environmental campaigners, however, almost invariably see it as 100-0.
If we are regularly being surprised in just one direction, if our models get blindsided by an ever-worsening reality, it does not bode well for our scientific approach. Indeed, one can argue that if the models are constantly inaccurate, it is probably because the models are wrong. And if we cannot trust our models, we cannot know what policy action to take if we want to make a difference.