The Past Decade’s Emissions Are Already Driving Worse Heat Waves in Europe

A woman shelters from the sun with a parasol on June 21, 2026 in Seville, Spain. —Marcelo del Pozo—Getty Images The heat waves Europe has seen in recent years were made measurably more intense because of the greenhouse gasses emitted since the 2015 Paris Climate Agreement, according to a new study published today in Geophysical Research Letters .

“We found that the emissions released since the signing of this Paris Agreement in 2015 have substantially and significantly increased the intensity of Europe's recent individual heat waves,” says lead author Jared Trok, a PhD student in Earth system science at the Stanford Doerr School of Sustainability.

The study also determined that that held true for Europe’s hottest week in every individual year since at least 2021.

Their findings come on the heels of this summer's back-to-back heat waves on the continent, which broke heat records and contributed to at least 35,000 excess deaths.

Read more: In Europe, Today's Children Will Live Through Nearly Twice as Many Fire Weather Days Than Their Grandparents The Paris Agreement was a legally binding international treaty on climate change adopted by nearly 200 countries in December 2015, with the aim of limiting global warming to 1.5°C above pre-industrial temperatures.

A decade later, the world is expected to blow past that 1.5°C target, with optimistic estimates finding that temperatures will peak at 1.8°C under current climate policies.

Beyond the 1.5°C threshold, every extra fraction of a degree matters.

The world can expect to see intensified extreme weather, ecosystem loss, and flooding in coastal cities and island nations, along with far-reaching impacts to human health and food security.

Europe is particularly vulnerable in the face of a warming climate.

The continent is heating up at more than twice the global average rate.

The June and July 2025 heat waves broke records across the continent—only to be surpassed by 2026 heat waves.

Surface air temperatures exceeded 40°C (104°F) in several countries, and up to 46°C (114.8°F) in Spain and Portugal.

The researchers created a generative AI model known as a diffusion model using simulated weather data from 10 global climate models to predict how extreme heat waves in Europe could have unfolded under different global emissions levels.

“This is a purpose built machine learning model that we trained on large amounts of climate model data…to make predictions about how individual heat waves might have unfolded differently if those same weather patterns had occurred under different levels of human emissions,” says Trok.