Global warming in the Alps can be seen from space

Global warming causes snow to melt on mountain ranges, which promotes increased vegetation. Satellite data shows that the latter has increased in almost 80% of the Alps, which is not good news for us.

The symbol of global warming is here melting of the glaciersas is the case in Arctic. This melting is spectacular in the mountains at high altitudes which are areas that are warming about twice as fast as the global average. This is worrying because these are hot spots of the biodiversity and ecosystem services. In recent decades, the snow cover has been considerably reduced, especially in the Alps where this reduction in snow is visible from space.

Published in the journal Scienceresearchers from the University of Lausanne and the University of Basel, together with colleagues in the Netherlands and Finland, analyzed spatio-temporal trends in snow cover and vegetation productivity in the Alps Europe with high-speed satellite data resolution over the past 38 years (1984-2021).

What are they observing from space?

The results of these remote sensing data showed that the snow cover had indeed decreased, by approximately 10% in the study region. This may not seem like much, but it must be emphasized that this is a worrying trend that will become more severe over time. Less snow means more vegetation and, indeed, the productivity of the latter increased by 77% above the limit of the trees in the studied area.

These observations therefore show that climate change has led to a decrease in snow cover and an increase in plant productivity, which is a process known as “greening”. It is tempting to think that this phenomenon could favor the sequestration of carbon but it is unlikely to outweigh the negative consequences. Indeed, greener mountains reflect less the light from Sun (reduction ofalbedo) and promote warming which, in turn, leads to the melting of the remaining snow cover. This vicious circle between snow and vegetation, called feedbackwill therefore lead to even more pronounced changes in the future.

Consequences of these changes

These modifications cause major changes in the environment; they affect the ecosystems and the surrounding populations. Indeed, the melting of glaciers and the thawing of the permafrost can lead to landslides, rockslides, mudslides and habitat loss further endangering fragile alpine plant and animal communities. In addition, snow and ice in the Alps play an important role in thewater supply drinking water, they provide nearly half of the world’s water resources. pure waterand its availability is increasingly threatened.

Although an increase in precipitation in the European Alps, the rapid warming induced in mountainous regions will reduce the amount of rain that will fall as snow. Scientists believe that the mass snowfall will be reduced by approximately 25% over the next 10 to 30 years.