As can be seen from space, the Alps are changing from white to green due to climate change

This is the conclusion of Swiss researchers who have analyzed high-resolution images of all the Alps taken from space in the last 38 years.

We were really surprised to find such a huge green trendSabin Rampoff, an assistant professor at the University of Basel and lead author of the study, told the Journal on Thursday. Science. In question: Decreased snow cover, and vegetation growth, due to rising temperatures.

The phenomenon is already well known in the Arctic, but so far little has been studied on a large scale for mountainous areas. However, these two places are warming much faster than the others on the planet, and researchers therefore suspect comparative effects.

For their analysis, they isolated areas above 1,700 meters above sea level, excluding areas used for agriculture. Above this height, forests were also excluded. Results: Observed at about 10% of the surface area, at the end of the analyzed period no more snow was present in the summer where it was at the beginning.

Sabin Rampoff also noted that satellite imagery allows us to simply verify the presence or absence of snow. However, the first effect of warming is to reduce the depth of the snowpack, which has been observed by local measurements. So “This may not seem like more than 10%, but that doesn’t mean nothing is happening in other areas

The vicious cycle of climate change

Second, the researchers compared plant quantities using wavelength analysis to determine the amount of chlorophyll present. The result was even more interesting: vegetation grew in 77% of the area observed.

It grows in three different ways: plants grow where no one has before, some grow and become denser due to more favorable conditions, and eventually the species develops naturally at lower altitudes and grows faster and easily colonizes higher areas.

It is climate change that is driving these changes“Sabin Rampoff said vaguely.”Warmth means long growing season“, And”The warmer it gets, the more rain falls as rain, not snow

3 All heat waves are improved by climate change, experts say

The consequences of this “green” are multiple. First, a large portion of drinking water comes from melting snow, the study noted. If water is not stored as snow, it quickly disappears through rivers.

In addition, the habitat of species specially adapted to the alpine environment is disrupted. And the loss of snow could hurt the ski tourism industry as well. Finally, “What we forget is the emotional side of these processes, the Alps being a symbol, and when people think of Switzerland, they often think of the Alps.“, Said Sabine Rampoff.

For the future, optimism does not meet. A vicious circle is actually set up: when snow reflects about 90% of solar radiation, plants absorb much more and then send it back in the form of heat. Which accelerates warming, and therefore melts snow and grows vegetation. Etc.

Green to brown?

However, the exact evolution of the Alps in the following decades remains unknown. “In terms of snow, it’s pretty clear. The snowpack will disappear even more, especially at lower altitudes“, Explains Sabine Rumpf.

But another phenomenon for the moment, the transition to brown – indicating that the land is no longer covered with snow or vegetation – has been detected in only less than 1% of the area studied. This is much less than what is observed in the mountains of the Arctic or Central Asia.

This tendency is fueled by two factors: an increase in the number of rainy seasons and then a drought, and the drying up of snow for plants.

We don’t know for the future if the brown transition will be more frequent and the trend will be reversed“Sabin Rampoff concludes that he wants to be able to renew these observations in a few years to verify this.

Professional or amateur photographer, did you paint a picture of our climate warming? Take part in Season 2 of the “Climate Eye” photo contest launched by GEO and MétéoFrance on the theme “Climate Change in France”. Participants are invited to share their photos before July 14th.

Read more:

With climate change, where do you live in France?

Climate change: Why are the peaks of the Alps turning green?

Climate change: Why are the peaks of the Alps turning green?

What are the best ski resorts in the Alps?

What are the best ski resorts in the Alps?

Leave a Comment