Credit: Windy

Europe’s summer has arrived early, and it has arrived hard.

Across the continent, a dangerous heatwave has closed schools, strained power grids, slowed trains, and pushed authorities to issue the highest health alerts. France recorded its hottest day ever by its national thermal indicator, while individual stations elsewhere also broke records. Italy placed major cities under red alert warnings. Spain topped 44° Celsius while Britain, where there’s barely any households with air conditioning, braced for temperatures near 40°.

Europe is warming faster than any other continent, and this recent heatwave came as a shocking reminder of the fact.

A Chain of Events

The planet is about 1.4° Celsius warmer than it was before the industrial era. Europe is about 2.4° hotter, according to the EU’s Copernicus Climate Change Service.

One reason is the continent’s geography. Land heats faster than ocean, and Europe is mostly land. Water can absorb heat and cool the air through evaporation.

Europe also stretches into the Arctic, which is warming even faster. As snow and ice melt, they expose darker land and ocean. Those darker surfaces absorb more sunlight, which adds more heat and melts more ice. Scientists call this the albedo feedback effect.

Cleaner air has ironically made things worse from a warming standpoint. Since the 1980s, Europe has cut aerosol pollution. That has certainly improved public health, but aerosols also reflect sunlight and help brighten clouds. With fewer of them, more sunlight reaches and heats the ground.

The rate of warming varies across the continent. Eastern and southeastern Europe, parts of central Europe and the Alps have warmed by 0.5 to 1° Celsius per decade over the past 30 years, according to Copernicus. Svalbard, the Norwegian Arctic archipelago, has warmed by as much as 1.5 to 2° per decade.

The Omega Heatwave A graphic of how the heat dome works. Credit: Washington Post

The current heatwave is being powered by a “heat dome” event—a broad zone of heavy, sinking air. That sinking air acts like a lid over the region. It clears away clouds, lets more sunlight reach the ground and squeezes the air below, making it hotter.

“Heat waves like this are associated with what we call high-pressure systems,” said Oscar Brousse, a lecturer in urban climatology and health at University College London, according to NBC News. “These systems suppress cloud formation, leading to more sunshine, which heats up the surfaces and, in turn, the air around us.”

Meteorologists describe the setup as an “omega block,” a high-pressure pattern named for its Ω-like shape on weather maps. This week’s heat episode followed such a pattern, with hot air drawn north from North Africa and held over Europe.

“We have a cold front located off the coast of Portugal that is acting like a heat pump, drawing up warm air… at altitude, high-pressure systems exert pressure on this warm air mass, and when we compress a warm air mass, we actually make it even hotter,” Sebastien Leas, a forecaster at Météo-France, told AFP.

Climate change raises the baseline. A rapid attribution analysis by ClimaMeter, a scientific project that studies the climate fingerprint of extreme weather, found that similar heatwave patterns now run about 2 to 4° Celsius hotter in parts of Europe than they did in the late 20th century.

A Health and Infrastructure Crisis The current heatwave map at the time I’m writing this article. Credit: Urban Heat Maps

The heat has caused a lot of disruption. France closed hundreds of schools, while in Paris, the Eiffel Tower and the Louvre restricted visiting hours. In Italy, Milan and Turin faced blackouts as air-conditioning demand surged. In Britain, rail operators reduced service to avoid heat-related failures.

For many Europeans, indoor life offers little escape. Older homes in Britain, France and elsewhere were designed to hold heat during cold winters. Only about one in five European households has air conditioning, according to the European Environment Agency and the International Energy Agency. That leaves many people relying mostly on shutters and fans. But even those may be counterproductive, as turning a fan on above 35 degrees typically makes things worse.

In London, Stefan Cretu told NBC News: “It’s almost like you can’t escape the heat.” He added: “It’s hot outside, and somehow it’s even hotter inside—my house feels like a trap.”

Heat kills directly through heatstroke and indirectly by worsening heart and lung disease. The World Health Organization’s Europe office said more than 200,000 people in Europe died from heat-related causes over the last four years, most of them preventable.

“The real way to stop heatwaves becoming increasingly severe is to tackle climate change itself,” Brousse concluded. “[Without that] there is only so much we can do.”