Switzerland and Italy are redrawing their Alpine border because of melting glaciers

As climate change causes glaciers to melt, Switzerland and Italy have redrawn a section of their border spanning a part of the Alps.

In 2023 alone, Switzerland’s glaciers lost 4% of their volume, according to data from the Swiss Glacier Monitoring Network, which reports on hundreds of the country’s glaciers every year. That drop was the second-biggest melt ever. Over 2022 and 2023 combined, Switzerland’s glaciers lost a total of 10% of their volume—the same amount of melt they experienced between 1960 and 1990.

The ridges of glaciers determine some sections of the Italian-Swiss border in the Alps, specifically under the Matterhorn peak. The Theodul Glacier near the Matterhorn was once connected to a neighboring glacier, but melting ice has since split the two apart. It’s near that area that the two countries have had to redraw a section of their border about 100 meters (nearly 329 feet) long, EuroNews reports.

“Significant sections of the border are defined by the watershed or the ridge lines of glaciers, firn, or perpetual snow,” the Swiss government said Friday in a statement, according to Bloomberg. “These formations are changing due to the melting of glaciers.”

Global warming is causing all Alpine glaciers to recede, affecting those natural boundaries and changing mountain routes. The area by the Swiss-Italian border that is being changed is near the Zermatt ski resort, which attracts millions of visitors a year.

Swiss officials approved an agreement to change the border with Italy last week, per the BBC, but Italy has yet to approve the change. A joint Swiss-Italian commission first made a draft agreement about the border back in May 2023.

Melting glaciers have been affecting the Swiss-Italian border since at least 2022, after part of the Theodul Glacier retreated and threw into question which country an Italian mountain lodge was technically in. The border between the countries ran along a “drainage divide,” an area on a mountain where the meltwater from ice and snow runs down either side of the divide—and in this case, toward either country.

But as the glacier has melted, that watershed’s location has moved. French news outlet AFP reported in 2022 that the shifting watershed began to creep toward, and gradually swept underneath, the building of the Rifugio Guide del Cervino, an Italian mountain lodge. That meant two-thirds of the lodge was technically in southern Switzerland, if still using the divide as the borderline.