Summer has only just begun, but severe heat waves are already hitting Europe. It stretches from Spain through Italy and Romania to Greece. The temperature peak is expected in the next few days and the European record of 48.8 degrees could even be broken. In a laconic tweet published on Thursday, which was viewed 1.7 million times, Green Paris MP Sandrine Rousseau expressed alarm at the temperature in our Iberian neighbors: “It’s 60 degrees in Spain. 60 degrees. »
Like her, many netizens shared this information in shock. The irritating satellite image of the European observatory Copernicus is widely shared on social networks: we see Spain in all shades of red, even black, which indicates an oppressive climate.
According to the European Copernicus Observatory, the surface temperature on Tuesday actually exceeded 60°C in Extremadura, a region in south-eastern Spain. And many temperature records (air) were achieved in Spain, but also in France, Switzerland or Germany. According to the European satellite, 13 of Spain’s 17 Autonomous Communities are currently classified as vulnerable to high temperatures, some of which are extremely vulnerable.
However, the shock figure of 60 degrees therefore refers to the ground temperature, not the air temperature. Which changes everything. “This corresponds to the temperature felt when touching the surface, it is different from the air temperature (up to 43°C on the same day),” explains engineer Thibault Laconde on Twitter.
The surface temperature of the ground “can be 15-20 °C higher than the air, depending on the type and color of the soil. In Spain it has never been 60°C! notes Doctor of Agricultural Climatology Serge Zaka.
This difference is also “rather classic in summer,” observes François Gourand, forecaster at Météo France. “On a sunny day, the sun’s rays warm the ground enormously, so it’s much warmer at ground level than a meter or two above. To say it’s 60 degrees is factually true, but it doesn’t compare to the temperatures you and I are feeling outside and communicating about. »
80.8°C on the ground in Iran and Mexico
Copernicus Sentinel-3 satellites closely monitor Earth’s surface temperature on a global scale. The European program emphasizes on its website that soil temperature should not be confused with air temperature. In 2021, the world land temperature record was broken with 80.8 °C in Iran and Mexico.
In addition, satellites are less reliable than measurements with thermometers: “Because the devices are far from the earth’s surface, they measure radiation with a resolution that is not necessarily very precise,” continues François Gourand. The calculations are much more complex. There’s bound to be some margin of error, it’s more of an idea. »
For some environmental activists and meteorologists, Sandrine Rousseau’s tweet serves the cause. “There’s nothing like ecologists being seen as idiots and exaggerators,” replies Thomas Wagner, founder of the blog Bon Pote, which focuses on the ecological emergency.
Despite the flood of reactions, Sandrine Rousseau persists: “So it’s 60 degrees,” she wrote this Friday morning.
The highest temperature record ever measured with a thermometer was 56.7 °C on July 10, 1913 in Death Valley, USA.