Yesterday, France recorded its hottest day since records began, with temperatures in parts of the Rhône valley exceeding 46°C. The event, which has been attributed to a heat dome drawing Saharan air northwards, is the latest in a sequence of extreme heat events that are becoming the new climatological baseline. For those of us who work with the numbers, the signal is unequivocal: the physics of a warming atmosphere leaves no ambiguity.
Yet the political response to this heatwave has exposed a fracture in European energy policy. In France, the government has announced emergency measures to expand air conditioning access in public buildings, a move that many see as a stopgap. Meanwhile, in the United Kingdom, the Department for Energy Security and Net Zero has quietly reaffirmed its strategy: focus on building resilience through passive cooling, district heating networks, and a rapid shift away from fossil fuel-based electricity generation.
The divide is not merely philosophical. Air conditioning is a massive load on electricity grids. A typical unit in a domestic setting draws the equivalent of a small electric car charging at full power. When a country like France installs hundreds of thousands of these units simultaneously, the peak demand spikes alarmingly. The UK’s approach, in contrast, relies on better building insulation, reflective roofing, and green spaces to lower ambient temperatures. It is a strategy that acknowledges the thermodynamics of the situation: it is far more efficient to keep heat out than to pump it away.
This is where the data gets interesting. The International Energy Agency’s latest report on cooling shows that global energy demand for air conditioning could triple by 2050. That would be the equivalent of adding the entire current electricity consumption of the United States and the European Union combined. The UK’s National Grid has already modelled scenarios where a widespread adoption of air conditioning could push peak demand beyond manageable levels, especially if the grid is still reliant on gas-fired power plants that struggle in high heat.
So why the divergence? The answer lies in political calculus. France has a large nuclear fleet that provides low-carbon baseload power but is not easily ramped up and down. Air conditioning represents a flexible demand that nuclear can serve. But the real issue is that French voters, like many across Europe, are demanding immediate relief from heat. The ‘solution’ of air conditioning is politically expedient, even if it locks in higher emissions and future strain.
The UK, by contrast, has a more diverse grid with growing renewables and interconnection. It also has a political system that, for now at least, is willing to take a longer view. The government’s Heat and Buildings Strategy, published last year, explicitly prioritises passive measures over mechanical cooling. This is not just about energy: it is about public health. The NHS already sees thousands of excess deaths during heatwaves, and the most vulnerable are often those without access to cooling. The UK strategy argues that ensuring every home is designed to stay cool naturally is a more equitable solution than relying on individual units that may be unaffordable to run.
I have no doubt the debate will intensify. As someone who studies planetary energy balance, I can tell you that we are approaching the point where even aggressive mitigation will not prevent adaptation being necessary. The question is what form that adaptation takes. Do we spend billions on air conditioning units that will generate more heat in cities and require more power, or do we invest in infrastructure that reduces the need for cooling altogether?
The UK is betting on the latter. But time will tell if its political resilience matches the physical resilience it seeks to build.
