Warming, But Far From Global

Guest Post by Willis Eschenbach

My mind wanders in curious back byways. I got to thinking about the “global” part of “global warming”. Over the past ~ quarter century, according to the CERES satellite data, here’s where the world has warmed and where it has cooled.

Figure 1. Areas of warming and cooling as shown by the CERES satellite dataset. White contours outline the areas that are cooling.

Now, before you get all passionate about how “nobody predicted that global warming would actually be global”, that’s true …

… and it’s also true that nobody predicted that India, South Africa, most of Northern Africa and South America, the North Atlantic, and the Southern Ocean would cool over that period, in some cases by a degree or more per decade.

Nor can any scientist or computer model explain WHY those specific areas and not other areas are cooling …

So I thought I’d take a look at what the models are saying about that same time period, March 2000 to February 2024. I used the models from the Computer Model Intercomparison Project 6 (CMIP6) in order to give the models every possible advantage.

Why is that an advantage? Well, because the historical data that they are trained to replicate goes from 1850 to 2014. It’s only in 2015 and later that they are actually predicting the future. Up until 2014, they have all the available observational data to train their model against.

So I went and got the surface air temperature outputs for 39 different models from the marvelous KNMI data site. Here are the first 12 of them, the rest are pretty much of a muchness.

Figure 2. Areas of warming and cooling as shown by twelve of the CMIP6 climate models. As in Figure 1, white contours outline the areas that are cooling. Note that by an error, I did not change the labels on the charts from my default, which is W/m2, to the proper label, which is °C/decade. Mea maxima culpa, but the creation of the graphics was quite laborious, so I’m not going to redo them.

As you can see, the results are what you’d call “all over the map”. The global trends range from ~ 0.10 °C per decade up to ~ 0.40 °C per decade. And every one of them shows very different areas and amounts of heating and cooling.

Now, the prevailing theory is that you get a more accurate answer by averaging what they call an “ensemble” of models. I’ve never believed that one bit; that seems like crazy talk. Average a bunch of bad models that disagree with each other to get a valid result?

Really?

But that’s what the climate megabrains do, so I averaged the 39 models to see what that looks like. Here’s that result.

Figure 3. Areas of warming as shown by the average of 39 of the CMIP6 climate models.

Now you may be wondering, where are the white contours outlining the areas that are cooling?

The answer is … there are none.

Because the areas of cooling predicted by each model are somewhat randomly scattered around the planet and the overall projection is one of warming, when you average them all, you end up with no average cooling anywhere … et voilà, you have “global” warming.

Funny how that works out.

With warmest wishes for everyone, I remain,

Yr. obt. svt.,

w.

PS: As always, I ask that when you comment, you quote the exact words you are referring to. It avoids endless misunderstandings.