Current DateSeptember 17, 2021

Global warming: in the Alps, the Presena glacier turns pink

In the Italian Alps, the snow from the Presena glacier had turned pink and this is not good news. This phenomenon caused by the presence of algae darkens the snow. As a result, it absorbs more sunlight.

In recent days, parts of the Presena glacier in the Italian Alps have turned pink. This well-known phenomenon is caused by the presence of algae of the species Ancylonema nordenskioeldii. They frequent the middle latitudes, but also the poles and are also present in Greenland.

The phenomenon is becoming more and more common. Last March, Ukrainian researchers on Galindez Island, north of the Antarctic, also witnessed a similar event. After analysis, it turned out that the culprit was another microscopic alga, Chlamydomonas nivalis, also called “snow algae”. Research published last May has also documented strange blooms of green algae on another part of the continent.

The “awakening” of algae

During the winter months, these plants remain dormant in the form of spores, quietly buried under a few inches of snow or ice. Once the environment heats up in spring and summer, excess light and liquid water then promote their germination.

The problem is that the snowmelt is accelerating. Last year, a report from the European Geoscience Union predicted that 90% of the current volume of glaciers in the Alps could disappear by 2100. For its part, the Presena glacier in question is not not to be outdone. Since 1993, the structure has thus lost a third of its volume.

The situation is such that every summer, to slow the effects of global warming, the staff at the Adamello station which operates the area spreads gigantic white tarpaulins to reflect maximum sunlight.

Vicious circle

These are not dangerous in themselves; the real concern is that they considerably darken the snow. As a result, it reflects less sunlight. However, what is not reflected is therefore absorbed.

In other words, the soil of this glacier stores more heat than usual, which then exacerbates the melting process, thus creating is a vicious circle. In fact, the more the ice in which this alga is contained begins to melt, the more these microorganisms will be able to obtain the water they need to proliferate.