Climate change is turning the Alps from white to green, study finds

The Alps, the most extensive and tallest mountain range located entirely within Europe, are a symbol of natural beauty and famous for winter sports. But, as the planet warms up due to climate change, the iconic white-capped peaks of the Alps are steadily turning green.

A study of high-resolution satellite data from 1984 to last year has revealed that areas with vegetation above the treeline in the Alps have increased by 77 percent since 1984, according to a press release from the University of Basel.

“The scale of the change has turned out to be absolutely massive in the Alps,” said lead author of the study professor Sabine Rumpf of the University of Basel, as reported by The Guardian.

The growing season has been lengthened by increased temperatures and rainfall, with plants spreading as they become taller and thicker. An increase in high-altitude vegetation could pose a threat to specialist Alpine plant species, Rumpf said, as they have adapted to the extreme conditions but aren’t extremely competitive and are at risk of being pushed out by more aggressive plants commonly found at lower altitudes.

“The unique biodiversity of the Alps is therefore under considerable pressure,” Rumpf said in the press release.

The study by a team of European researchers, “From white to green: Snow cover loss and increased vegetation productivity in the European Alps,” was published in the journal Science.

For the study, forests, glaciers and areas below 1,700 meters were excluded by the researchers, the press release said. But in nearly ten percent of the remaining area there was a marked decrease in snow cover, which the researchers said was concerning.

“Previous analyses of satellite data hadn’t identified any such trend,” Antoine Guisan, one of the study’s two senior authors, said in the press release. “This may be because the resolution of the satellite images was insufficient or because the periods considered were too short.”

The satellite images show snow cover, but don’t offer information on snow depth.

“For years, local ground-based measurements have shown a decrease in snow depth at low elevations,” said study author Grégoire Mariéthoz of the Institute of Earth Surface Dynamics at the University of Lausanne in Switzerland, the press release stated. “This decrease has already caused some areas to become largely snow-free.”

As more of the Alps transform from white, snow-covered wonderland to verdant landscape lush with vegetation, less sunlight will be reflected, leading to greater warming.

“Greener mountains reflect less sunlight and therefore lead to further warming – and, in turn, to further shrinkage of reflective snow cover,” Rumpf said in the press release.

As warming increases, it will speed up the thawing of permafrost and glacial melt. Rumpf also pointed out that ice and snow from the famous mountain range provides drinking water, as well as the basis for tourism and recreational activities.