Around the world, mountains are warming faster than surrounding lowlands, scientists warn. More intense heat is melting glaciers and diminishing snowfall, threatening a vital source of fresh water for more than a billion people, according to an exhaustive review of scientific research.
It is clear that warmer weather is altering mountain landscapes, said lead author Nick Pepin, of the University of Portsmouth. “What’s less well known is that as you go higher into the mountains, the rate of climate change can become even more intense.”
Pepin and his colleagues analyzed data on shifting temperature, rainfall, and snowfall across mountain ranges, from the Rockies to the Alps to the Himalayas, from 1980 to 2020. They found that, compared to lowlands, mountains are warming by another 0.21 degrees C per century. Data shows that as alpine areas heat up, snowfall is turning to rain, and rain is becoming more erratic. The research was published in Nature Reviews Earth & Environment.
The rapid warming in mountain regions mirrors changes in the Arctic, which is heating up to four times faster than the rest of the world. In both cases, the loss of snow, which reflects sunlight, is intensifying warming.
Scientists say that hotter weather in alpine regions threatens vital stores of fresh water held in glaciers and snowpack, water that flows downslope throughout the spring and summer as ice melts. The Himalayas — which supply water to India, China, and Southeast Asia — are losing ice faster than was previously thought, the research found.
More severe mountain rainfall is also raising the risk of flooding. This summer, record cloudbursts in the Himalayas fueled deadly floods across Pakistan which destroyed as much as half of the summer harvest.
Scientists also warn that mountain animals are being cornered by warming. “As temperatures rise, trees and animals are moving higher up the mountains, chasing cooler conditions. But eventually in some cases they’ll run out of mountain,” Pepin said. With nowhere left to go, he said, alpine wildlife could be “fundamentally changed.”
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