The UN’s international climate group has revised its set of possible climate change scenarios. They eliminated the most damaging scenario, because of progress in sustainable technologies and because details of the scenario itself seemed unlikely to occur. Trump and other climate deniers have seized upon this change to claim it shows all discussion of climate change is bogus. The following piece was done as a comment to an article in the NY Times.

It seems to me one of the problems with this discussion of scenarios is that people want the scenarios to tell them something different than what the scenarios are trying to do. The scenarios are attempts to model different levels of response to the problem of climate change. There is no default case where we do nothing. For that case the only limit to the temperature is the end year in the study—the temperature would just keep increasing.

The main thing that has happened since the original scenarios is that the world has taken some measures that help: costs of wind and solar solutions have come way down to the point that those make up the majority of new electricity generation worldwide. Electric cars have become cheaper, better, and more prevalent. So it’s not surprising that the current view is somewhat more optimistic.

Where that actually leaves us can never be completely clear. I’m willing to bet the models never considered that the most powerful country in the world would be run by someone trying to sabotage the whole effort. Or that data centers would suddenly demand more power than cities. Or that the Iran war would show everyone the risks of imported oil. There will always be reassessments.

This new set of scenarios should make us appreciate the work that has been done. We can make progress against climate change. But there is much that needs to happen and very strong forces against it. This will never be easy, but it needs to be done.