Heat waves in Portugal 40 times more likely

Climate change caused by human activity has increased the risk of heat waves like the one that fueled deadly wildfires in Portugal and Spain in August by 40 times, according to a study released Thursday.

The Iberian Peninsula, in the extreme southwest of Europe, has seen exceptionally high temperatures over the past month , exceeding 40 degrees Celsius in many regions.

Persistent heat has fueled wildfires, mainly in northern Portugal and western and northwestern Spain, killing four people in each country, forcing thousands to evacuate and devastating vast areas of land.

Fire against fire, retardants and "let it burn": this is how we fight mega fires, which will become increasingly common.

Climate change, caused primarily by the burning of fossil fuels, has made fire-prone weather conditions about 40 times more frequent and 30% more intense, according to European scientists who worked on the study for the international group World Weather Attribution.

“Without human-caused warming, such fire-prone weather conditions would only occur once every 500 years , rather than once every 15 years as they do now,” Theo Keeping, a researcher at Britain’s Imperial College London, told reporters.

2024, the hottest year ever. Portugal accounted for 25% of the burned area in Europe.

Periods of intense heat quickly dry out vegetation and can spark intense fires, which "can generate their own wind, leading to increased flame spread, explosions, and the ignition of dozens of nearby fires from embers," he added.

Another factor that has worsened the impact of global warming is the rural exodus , which has left vast areas of land less utilized than before, according to Maja Vahlberg, a consultant at the Red Cross and Red Crescent Climate Center.

"The decline of traditional agriculture and grazing reduces natural vegetation control. Lands that were previously inhabited and cultivated have therefore become more flammable," he added.

"From a human perspective, most of these rural areas have suffered massive abandonment since the 1970s, which has allowed fine fuels to accumulate to dangerous levels, a problem exacerbated by inadequate forest management," said Ricardo Trigo, professor in the department of geophysics, geographic engineering and energy at the University of Lisbon.

In Portugal, more than 280,000 hectares have been burned since the beginning of the year, according to the European Forest Fire Information System, which has been collecting this data since 2006.

Spain, in turn, lost more than 380 thousand hectares, a new record.

The heat wave that hit Spain for 16 days in August 2025 was “the most intense on record”, with average temperatures 4.6 degrees higher than those observed in previous waves, according to the Spanish national meteorological agency AEMET.

The agency has recorded 77 heat waves in Spain since it began keeping records in 1975, six of which were four degrees or more above average. Five of these have occurred since 2019.

According to an estimate released Tuesday by the Carlos III Health Institute, more than 1,100 deaths in Spain can be attributed to the August heat wave.