Posted on 15 December 2025 by Ken Rice

This is a re-post from And Then There's Physics

Since effective communication often involves repeating things, I thought I would repeat what others have pointed out already. The underlying issue is that there is a narrative in the climate skeptosphere suggesting that extreme weather events are not becoming more common, or that we can’t yet attribute changes in most extreme weather types to human influences (as suggested in the recent DoE climate report).

Table 12.12 from the IPCC AR6 WGI report.

This is often based on the Table shown on the right, taken from Chapter 12 of the IPCC AR6 WGI report. As, I think, originally pointed out by Tim Osborn, this table is not suggesting that we haven’t yet detected changes in most extreme weather events, or haven’t managed to attribute a human influence. It’s essentially considering if, or when, a signal has/will have emerged from the noise. Formally, emergence is defined as the magnitude of a particular event increasing by more than 1 standard deviation of the normal variability.

In some sense it’s highlighting when the typical properties of these events will be outside the range of what was normal in the baseline climate. As Andrew Dessler points out in this post, this does not indicate that we have yet to detect a change or attribute a human influence. Detection and attribution does not require emergence. You can detect a trend and attribute a human influence before the signal has emerged. For many extreme events, changes have indeed been detected and in many cases have been attributed to human influences.

Of course, there is a prominent voice in the climate skeptosphere who thinks Andrew Dessler is wrong and that it is ironic that someone trying to police the scientific discourse doesn’t understand IPCC terminology (as an aside, complaining about others being science police may itself be rather ironic). Given that one of the co-ordinating lead authors has posted a comment on Linkedin that seems entirely consistent with Andrew’s post, the irony might be that someone professing to be an honest broker doesn’t really understand the topic nearly as well as they seem to suggest that they do. Of course, this will be surprising to noone familiar with the public climate debate.

I do find this all rather fascinating, but also concerning. Confident voices can become prominent and be treated as domain experts when they present arguments that are convenient to some audiences, even if they really don’t understand the topic nearly as well as their confidence would seem to suggest. Anyone paying attention at the moment is certainly not going to be surprised by something like this, but it still seems worth considering how to improve the dialogue or how to counter those who rise to prominence mostly by promoting erroneous, but convenient, arguments. Pointing out when they’re wrong seems like a reasonable place to start, even if it clearly won’t be sufficient.