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Scientists discover snow algae speeding up Arctic glacier melting
© Mikhail Flint

Scientists discover snow algae speeding up Arctic glacier melting

Red algae that can grow inside ice formations and on their surface are among the main causes contributing to the unprecedented speed of ice melting over the past few years, RIA Novosti reports. German climatologists reached this conclusion in an article published in Nature Communications.

"Our results point out that the ‘bio-albedo' effect is important and has to be considered in future climate models," lead author Stefanie Lutz from Helmholtz Center Potsdam said in a statement

Lutz and her colleagues observed a relatively new Arctic phenomenon called "bio-albedo" ("biological reflectivity") that scientists, including Russia's polar explorers, first spotted in the early 2000s. In certain conditions, including relatively high temperatures, single-cell algae drifting in the waters of the Arctic Ocean and often being deposited on the surface of local glaciers start reproducing actively when the snow and ice tend to melt down.

Therefore ice and snow formations lose their traditional white color and assume a reddish or brownish tint. In the context of climatology, ice formations can no longer effectively reflect sunlight; they start absorbing more heat and melt away more rapidly.

Scientists were aware of this effect for quite a while but did not try to assess its scale until now. A group of researchers did their best to fill in this gap by visiting the coasts of Greenland, Iceland and Svalbard. They took water and snow samples from 21 Arctic glaciers and eventually found that the "cosmopolitan" snow algae were responsible for the "bio-albedo" effect whose scale was underestimated several times over. Their "cosmopolitan" essence was manifested in the fact that one and the same microscopic members of the plant kingdom inhabited all the Arctic regions visited by the German scientists. This means that algae will eventually start blooming all over the Arctic.

This study is important because blooms of algae are more dangerous for the climate than scientists previously believed. The article's authors assume that this particular algal bloom reduces ice albedo levels by 13 percent, which considerably speeds up their melting.

The situation is made worse by the fact that this process is, in effect, a chain reaction with positive feedback. Rapidly melting glaciers accelerate algae growth. Ice and snow then become even darker, and the cycle eventually resumes. All this proves that global warming forecasts should take the above-mentioned phenomenon into account, Lutz and her colleagues write in conclusion.