Tropical nights already arrive in the Pyrenees, which gains a month of summer

BarcelonaThe Pyrenees are warming up at cruising speed due to the climate crisis. The average temperature across the mountain range has increased by 1.9 °C since 1959, a figure that rises to 2.7 °C in the summer. This means that, since the mid-20th century, the Pyrenees have lost twenty frosty days per year and gained 32 summer days (days with temperatures above 25 °C). Or, in other words: every decade, 3 frosty days are lost and 4.9 summer days are gained.

This is the conclusion of a cross-border study of the entire Pyrenees led by Meteocat and linked to the European project LIFE Pyrenees4Clima. The data also indicate that the duration of periods of consecutive days with extremely high maximum temperatures is increasing, and the duration of spells with very cold values is decreasing. This trend is general throughout the Pyrenees, from the Cantabrian Mountains to the Mediterranean. In contrast, precipitation patterns differ depending on the area.

“Just as the temperature increase is uniform across the Pyrenees, with precipitation we have observed significant differences; while the northern slope and the Atlantic influence zone do not experience a significant change, the southern slope and the Mediterranean influence area are suffering a decrease in rain and snow in recent years”, explained Jordi Cunillera, head of the Climate Change team at Meteocat, in statements to ARA.

Furthermore, extreme heat, which has intensified in our region in recent years, has caused some tropical nights to appear for the first time in the Pyrenees, something unthinkable years ago. In recent summers, some minimum temperatures have been recorded that have not dropped below 20 °C in some valleys, especially below 800 or 700 m altitude. “All temperature indicators are increasing, and until just a few years ago, tropical nights had never been recorded in the Pyrenees”, points out Cunillera.

Goodbye to glaciers

And it is that mountain areas around the world are the ones that most notice global warming for a clear reason: the loss of ice and snow. “Before, many areas from altitudes of 1,500 or 2,000 m spent a good part of the year with good ice and snow cover that acted as a refrigerator; but with global warming, this layer lasts less and less, and this causes a more marked rise in temperature,” assures the expert.

The study indicates that the trend will be for increasingly warmer periods throughout the Pyrenees and more droughts, especially on the southern slope, and this will make snowfall less important and abundant. “Snowy winters with spectacular depths like the one we have experienced this year will be less likely,” explains Cunillera. The report also highlights that Pyrenean lakes are covered by ice for less time each year and suffer more heatwaves in their waters, and this “seriously” affects ecosystems. In Catalonia, permanent glaciers disappeared years ago, and in the Pyrenees as a whole, very few remain.

The European program LIFE Pyrenees4Clima is coordinated by the Pyrenean Observatory of Climate Change, a cross-border initiative of the Pyrenean Working Community (CTP). 46 public and private entities participate. Meteocat leads the climate part of the project, but other working groups are analyzing data and carrying out more studies, such as on the impact of climate change on the Pyrenean ecosystems or future climate projections. In this regard, based on the data obtained, pioneering adaptation trials are being carried out to the effects of the climate crisis in forty or fifty years so that they can be extrapolated to the entire Pyrenees and to other areas of the world.