The Alps are the highest and most extensive mountain range system in Europe, stretching approximately 1,200 kilometers across eight Alpine countries: Austria, France, Germany, Italy, Liechtenstein, Monaco, Slovenia, and Switzerland. They are geographically important, representing 11% of Europe’s surface and heavily influencing its climate.
All around the world climate change is increasing the risk of extreme weather events with more intense rain and snowfall, more frequent and intense heat waves, and longer droughts. In the Alps the effects of climate change are even more extreme and perceptible than in other regions.
The effects of climate change on the Alps in numbers
All regions in the Alps are considerably warmer than they used to be. The near-surface air temperature has risen over the last 150 years by about 2 °C – a considerably greater increase than the worldwide average. Nine out of the ten warmest years since records began have been in the 21st century.
Since 1980, sunshine has increased by 20% in the Alps, which, combined with what is referred to as the feedback effect further accentuate global warming: Like a mirror, glaciers reflect solar energy. If the surface area of the mirror is reduced, the amount of reflection also decreases, and the sun heats up the planet even more.
Heavy precipitation events have become more intense and more frequent. Summer precipitation in the Alps will decrease, while winter precipitation increases. These changing patterns of precipitation are increasing the likelihood of flood and devastating events. Conversely, the summers will become drier and warmer, exposing the Alps to risk from forest fires and drought.
From 1960 to 2017, the Alpine snow season shortened by 38 days—starting an average of 12 days later and ending 26 days earlier than normal. Europe experienced its warmest-ever winter in the 2015–2016 season, with snow cover in the southern French Alps just 20% of its typical depth.
The Alps maintain a permanent snow blanket over 2750 meters above sea level, and have many glaciers. Unfortunately, the vast majority of these glaciers are in retreat. They have lost approximately half of their volume since 1900, with clear acceleration since the 1980s. Glacier retreat is expected to continue in the future which will affect freshwater supply and run-off regimes, river navigation, irrigation and power generation.
The European Alps are home to over 4400 wild plant species, of which some 800 are exclusively alpine. On the higher slopes above the tree line, a wide variety of endemic and endangered species can be found European plant species might have shifted hundreds of kilometers northwards by the late-21st century and 60 % of mountain plant species may face extinction.
During heatwaves, temperatures may now surpass freezing point as high as 4,600m-4,800m altitude – higher than nearly all the Alps – causing permafrost to melt. Between granite blocks cracks have been filled for thousands of years by ice. In theory, because of the negative temperatures, higher mountain ranges should be permanently frozen … But with the rise of temperatures, the ice which cements the layers tends to melt thus destabilizing the rocks and generating an increase in frequency and volume of collapses.
Swiss National Centre for Climate Services, European environment agency, European Alpine Seed Conservation Network