That Europe is warming faster than the global average just like everywhere else is a running inside joke here at CDN. Oh, the fun we have. But seriously, Europe has been experiencing hotter and hotter summers since 1980, and there are two current lines of research on this that we will discuss this week and next. We’re saving for next week the theory that greedy oil companies, er, caused clouds to thin out and allowed more sunlight to hit the surface, because this week we look at how the greedy oil companies, er, cut pollution emissions and caused more warming. Yes, according to two recent studies the excess warming was caused by cutting emissions, not of CO2 but of sulphur, evidently a kind of anti-GHG though also a real actual ack-I-can’t-breathe pollutant. So EU leaders who consider warming the biggest existential threat we face have to decide what really matters. They could relax their strict sulphur emission regulations and cool things down. Or if they’re not willing to do so, they could stop complaining about the warming because they evidently don’t think it’s that big a deal plus they accidentally caused it, not the oil companies.

Since even climate modelers privately admit that models that don’t model well are bad, there have been various theories about what the models are missing, mostly things to do with complex parts of the atmospheric circulation system that draw heat into Europe from the south, or promote high pressure ridges. But it’s actually been known for a long time that the reduction in sulphur emissions associated with strict air quality rules in the EU removed a lot of cooling aerosols from the air. And they’re cooling because those tiny floating shiny objects reflect sunlight back to space, which means that cleaner air lets more sunlight hit the ground, warming the continent. Which makes it more than a little awkward that despite knowing all about it, climate models couldn’t reproduce all the warming it caused. They just don’t work very well.

The first of these two studies, published in 2025 by a team from the UK, began by noting the rapid pace of European summertime warming, and argued that models were able to reproduce it only because “these models warm too fast in the global mean”, which means the models run too hot overall, getting local European conditions right because they get global conditions wrong. Which is not an accomplishment. As the authors say, when they reproduce the warming in Europe “they get the right answer for the wrong reasons.”

Of course if their overall warming were scaled down to get the global average warming right they would then underestimate the warming in Europe. Which would not be an accomplishment either because a theory that underpredicts isn’t better than one that overpredicts. It’s still wrong.

To try to untangle this mess, the authors used data from climate models to argue that declining aerosol levels are driving warming in Europe and so are atmospheric circulation changes, which account for about 30 percent of the warming. But they didn’t look specifically at what circulation changes are involved, so there was a call for further study on the question.

Which brings us to the newer of the two studies in question (June 2026), by a team from Barcelona and Exeter Universities. They too noted that climate models underestimate the warming of the EU over the past few decades, which means it can’t be explained by the standard CO2-driven mechanism inside models. And to try to fix this long-standing irritant, the Barcelona team looked instead at what lower aerosols might do to atmospheric circulation, and whether it would contribute to heatwaves in Europe.

One of the patterns they noticed was that, in models at least, lower aerosol levels led to an increase in atmospheric wave patterns called Quasi-stationary Rossby Waves (which the authors abbreviate as QSWs), which is a cool name and which are associated with blocking patterns that, in summer, cause higher temperatures and heat waves. But while the models generated QSW activity that looked similar to observations, the effect was too small. So they argue that maybe the models are right, they just need that particular effect boosted. When they do so, voila, the excess warming in Europe is accounted for. Which if true would help save the models but at the expense of the theory they exist to support, since it would be yet more warming not due to CO2.

So we have two recent studies acknowledging the EU is warming rapidly, and it can’t be explained in climate models by CO2 emissions. Instead it is likely caused by air pollution reductions which remove aerosols, thus removing their cooling effect, and indirectly causing large-scale circulation changes that promote blocking events and summertime heatwaves. How then to cut warming? As noted, one way would be to relax the stringent EU sulphur pollution control rules. But those rules do have a legitimate purpose, to reduce some actual pollution, and they seem to have been fairly effective in ways that clearly enhance human well-being.

So if they aren’t willing to make that trade-off, they need to reassess why they keep calling warming our biggest existential threat, a menace to all life on earth, while simultaneously insisting that it’s less threatening than the smog levels our grandparents took for granted.