Climate change contributed to the intensification of the recent episode of heat that occurred in extensive regions of Spain and in the Maghreb. The heat wave with record temperatures that was seen at the end of April in southern Spain, Portugal, Morocco and Algeria would have been "almost impossible" without the influence of climate change caused by humans. Warming made an extreme event like this at least 100 times more likely than in a no-climate-change scenario. So indicates a rapid weather attribution analysis conducted by an international team of climate scientists who are part of the World Weather Attribution group. It is the first time that a study of this type has been carried out referring to the Peninsula and the Maghreb.
At the end of April, various areas of Spain, as well as other parts of southwestern Europe and northern Africa experienced a massive heat wave that brought extremely high temperatures, never before seen in these regions at this time of year. Temperatures reaching 36.9-41°C were measured in all four countries.
This episode of heat broke temperature records by a large margin, in the context of an intense drought.
Around the world, climate change has made heat waves more frequent, longer and more intense, climate scientists have been warning.
Now, scientists from Morocco, France, the Netherlands, the United States and the United Kingdom - but none from Spain - have collaborated to assess to what extent human-induced climate change altered the probability and intensity of this 3-day heat wave that occurred from April 26 to 28, 2023, in the most affected region
To assess the effect of climate change on these high temperatures, they analyzed weather data and computer model simulations to compare the current climate, which has warmed by about 1.2°C since the late 19th century, with the current climate. of the past, following peer-reviewed methods.
The researchers found that climate change made a heat wave at least 100 times more likely and led to temperatures up to 3.5°C higher than they would have been without climate change.
“As the planet warms, these situations will become more frequent and will require long-term planning, including the implementation of sustainable agricultural practices, models and effective water management policies,” said Fátima Driouech, an associate professor at Mohammed Polytechnic University. VI, one of the study authors.
The study finds, as has been seen in previous analyzes of extreme heat in Europe, that extreme temperatures are increasing faster in this region than climate models have predicted, a matter that is currently under intense investigation.
In the future, with a climate 0.8°C warmer (until global warming of 2°C above pre-industrial levels is reached) that heat wave would be 1°C warmer, but this is considered likely to be a very conservative estimate.
Sjoukje Philip, a researcher at the Royal Netherlands Meteorological Institute, noted that "temperature records have been broken again by a wide margin", something that has occurred in other areas of the planet affected by heat waves. For him, the fact that "temperature trends in the region are higher than what models predict shows that we need to better understand the regional effects of climate change so that we can adapt to even more extreme heat in the future."
"Until general greenhouse gas emissions are stopped, global temperatures will continue to rise and events like these will become more frequent and severe," these experts say in an official statement.
The Mediterranean region has been experiencing a very intense and long-lasting drought, and these high temperatures, "occurring at a time of the year when it should be raining, are making the situation worse," says Friederike Otto, co-founder of the World Weather Attribution (WWA ), the group dedicated to determining how much climate change influences an extreme event.
Otto is Senior Lecturer in Climate Science at the Grantham Institute for Climate Change and the Environment. “Without quickly halting the burning of fossil fuels and adapting to a hotter and drier climate, loss and damage in the region will continue to increase dramatically,” she adds.
"This rapid attribution exercise shows that without human-induced climate change, this situation would not have occurred," says Manola Brunet, a professor in the Department of Geography at the Rovira i Virgili University (URV), who highlights how "early" It's been this heat wave.
"This unusually warm event has been intensified by climate change, in a region of the planet, the western Mediterranean, which is warming twice as fast as it is observed on a global scale," adds Brunet, president of its International Commission on Climatology.
The authors of the study indicate that the Mediterranean has emerged as "one of the regions most vulnerable to climate change in Europe." Its western zone is considered a hot spot for climate change, as it is located in a transition zone between temperate and subtropical climates.
“We are experiencing faster warming than other parts of the world; And it is already a proven fact that heat waves are not only going to occur in the summer season, but that this warm part of the year is increasingly extending to the spring and autumn months”, says Brunet, the climatologist.
The intense heat wave added to a previous multi-year drought, which exacerbated the lack of water in regions of the Western Mediterranean and is threatening the yield of the 2023 crops.
“Early season heat waves tend to be more deadly as people have not yet prepared their homes or acclimatized to summer temperatures,” said Roop Singh, senior climate risk adviser at the UN Climate Center. Red Cross.
“In Spain, for example, we saw heatwave adaptation measures put in place earlier than usual, which is exactly the type of adaptive thermal action we need to see more of to reduce heat deaths,” Roop Singh added.
While people in the Mediterranean are no strangers to high temperatures, the fact that they occur in April in combination with the current ongoing drought makes the impacts more likely to increase.
The region of South West Europe and North Africa experienced such high temperatures that these are usually only seen in July and August, at the end of April 2023.
In southern regions of Spain, Portugal, Morocco and Algeria, up to 20 degrees more than normal was measured at this time of year.
In Portugal and mainland Spain, the national record for April was broken by a very wide margin, with 36.9°C and 38.8°C respectively, measured in the extreme south of the countries.
In Morocco, several April (local) records have been broken across the country and temperatures exceeded 41°C in some cities such as Sidi-Slimane, Marrakech, Taroudant.
Temperatures exceeded 40°C in Algeria on April 28 (at least in Maghnia, Mascara-Ghriss). These record temperatures added to a historic multi-year drought in those regions, exacerbating the heat impacts on agriculture already threatened by increasing water scarcity as a result of the combined effect of climate change and water use.
