As Europe endures increasingly severe heat waves — with June temperatures exceeding 40°C and shoppers in France scrambling for fans and air conditioners — demand for cooling is surging across a continent that is warming faster than any other. This matters because air-conditioning in Europe is shifting from a luxury to a matter of health and survival, yet the technology carries a serious environmental cost, making the question of how Europe cools itself one of the defining climate dilemmas of the coming decades.

Only around 20 per cent of Europeans have home air-conditioning (just 4 per cent in the UK), against roughly 90 per cent in the US, and the issue has become politically charged, with figures such as Marine Le Pen and the British Conservatives championing wider access while critics warn it benefits the wealthy and locks in high energy use. Cooling already accounts for about 3 per cent of global greenhouse emissions, and demand could more than triple by 2050. Conventional units also rely on problematic refrigerants — the EU began phasing out potent fluorinated gases in 2024 — prompting researchers to develop refrigerant-free "solid-state" alternatives, such as Saarland University's elastocaloric nickel-titanium system, which could cool rooms by 5–10°C more efficiently than today's machines.