Europe’s heat wave puts rapid warming in focus

Britain, France, Italy and Spain have issued red alerts and health warnings across much of their territory as another heat wave grips Europe, AFP reported. The episode, the region’s second since May, highlights climate data showing Europe is heating faster than the global average.

The EU’s Copernicus Climate Change Service says the planet is about 1.4C warmer than during the preindustrial period of 1850 to 1900. Europe, by comparison, is about 2.4C warmer than that baseline, according to Copernicus.

AFP reported that long-term global warming is mainly driven by greenhouse gases released from burning oil, gas and coal. Regional differences matter, too: land areas heat faster than oceans because water can store more heat and also cools through evaporation.

Weather patterns are favoring heat

Copernicus says changes in atmospheric circulation have made European summer heat waves more frequent and more intense. Carlo Buontempo, the service’s director, told AFP that high-pressure systems have become more common in Europe, especially in summer, over the past two or three decades.

Those systems bring stable weather and higher temperatures. Buontempo said scientists are still debating whether the increase in that specific pattern stems from climate change or from statistical variation.

AFP reported that Europe’s May heat wave was linked to a “heat dome,” a stalled high-pressure system that traps hot air over an area. This week’s heat episode is tied to an “omega” pattern, named for its resemblance to the Greek letter, according to the report.

Sebastien Leas, a forecaster at Meteo-France, told AFP that the current pattern involves hot air moving north from North Africa. He said a cold front off Portugal is helping pull warm air upward, while high pressure compresses that air mass and raises temperatures further.

The Arctic connection adds pressure

Europe’s geography also helps explain its faster warming, AFP reported. The continent extends into the Arctic, which is now 3.2C warmer than preindustrial levels.

Part of the Arctic’s heating comes from what scientists call albedo feedback. Snow and ice reflect sunlight, but when they melt, darker land and ocean surfaces absorb more heat, accelerating local warming.

AFP reported that the same process affects other parts of Europe where winter snow cover has declined. As snow retreats, darker ground is exposed for longer periods.

Cleaner air has a warming side effect

Europe has also cut aerosol pollution since the 1980s through tougher air-quality rules, AFP reported. Those tiny airborne particles can cool the climate by reflecting sunlight and making clouds more reflective.

Reducing that pollution improves air quality, but it also removes some of the cooling effect that aerosols had provided, according to AFP.

Warming rates vary by region

Copernicus data cited by AFP shows sharp differences within Europe. Eastern and southeastern Europe, along with parts of central Europe including the Alps, have warmed by 0.5C to 1C per decade over the past 30 years.

Western and southwestern Europe, along with sub-Arctic areas of Finland, Norway and Sweden, warmed by 0.2C to 0.5C per decade over the same period, according to Copernicus.

Svalbard, the Norwegian Arctic archipelago known for polar bears, has warmed by 1.5C to 2C per decade, AFP reported. The archipelago recorded its highest summer temperatures from 2022 to 2024, and last year was its fourth-warmest summer on record.

This story draws on original reporting from Phys.org.