The early-season heat wave that broiled parts of Algeria, Morocco, Portugal and Spain last week almost certainly would not have occurred without human-induced climate change, an international team of scientists said in an analysis issued Friday.
A mass of hot, dry air from the Sahara parked itself above the western Mediterranean for several days in late April, unleashing temperatures that are more typical of July or August in the region. Mainland Spain set an April record of 101.8 degrees Fahrenheit, or 38.8 Celsius, in the southern city of Córdoba. In Morocco, the mercury climbed to more than 106 degrees Fahrenheit in Marrakesh, according to provisional data, very likely smashing that nation’s April record as well.
A three-day stretch of such scorching heat in April is already quite rare for the region in the planet’s current climate, with just a 0.25 percent chance of occurring in any given year, according to the new analysis. But it would have been “almost impossible” in a world that hadn’t been warmed by decades of carbon emissions, said Sjoukje Philip, a climate scientist at the Royal Netherlands Meteorological Institute and an author of the analysis.
Because of climate change, last month’s hot spell was at least 3.6 degrees Fahrenheit warmer on average than a similarly improbable one would have been in preindustrial times, the scientists found.
Why It Matters: The region is already reeling from droughts.
The Iberian Peninsula and North Africa have been grappling with drought for years.
Scant rainfall in Morocco has harmed wheat yields and increased the nation’s imports. Food prices there are rising rapidly. Heat and poor rains decimated olive production last year in Spain, which is Europe’s biggest producer of olive oil. The global price of olive oil is the highest it’s been in 26 years.
Water scarcity has already had significant effects on livelihoods in the region, said Fatima Driouech, an environmental scientist at Mohammed VI Polytechnic University in Morocco and another author of the new analysis. “And the future, unfortunately, is not expected to be better,” she said.
Extreme heat can also set the stage for devastating wildfires. Last year was the European Union’s second most severe for wildfires since records began in 2000. Fires in 2022 burned more than 780,000 acres of land in Spain, the continent’s worst-affected nation, and 270,000 acres in Portugal.
Background: Climate change is fueling extreme heat worldwide.
Climate scientists have no doubt that global warming is making severe heat more likely and more intense on every continent. But to determine precisely how big that influence is for any single weather episode, they need to perform what is called an attribution analysis.
They use computer models to study the same event in what is effectively two alternate histories of the global climate: one that is responding to the effect of decades of greenhouse gas emissions, and one that isn’t. Scientists have used this approach to examine not just heat waves, but droughts, storms and cold spells, too.
The analysis of April’s heat was conducted by researchers associated with World Weather Attribution, a scientific initiative that investigates extreme weather events soon after they happen. The new analysis hasn’t yet been peer reviewed or published in a scientific journal, though it relies on widely accepted methods.
What’s Next: El Niño could soon start to raise the mercury globally.
Weather forecasters worldwide are bracing for a big shift. For the first time in three years, the global climate pattern known as El Niño is expected to materialize, most likely later this year. It isn’t yet clear how strong this El Niño will be or how long it might last. But in general, the phenomenon is associated with above-average global temperatures.
Coming on top of the planet’s steady warming from the burning of fossil fuels, the development of El Niño could lead to more record-breaking temperatures in many places this year.