Ice and snow in Antarctica are melting as a result of climate change, and not only because of rising temperatures: traces of soot and dirt are also to blame, which are deposited on the snow as a dark, carbonaceous veil. The surface then reflects less sunlight, heats up and melts more. In areas that are particularly badly affected, the shell of frozen water can become about 23 millimeters thinner than in the previous year every summer, Sarah Feron and her team from the University of Groningen report in the journal Nature Communications.
The researchers had previously collected samples of ice and snow from 28 locations in Antarctica, covering an area from the northern tip of the continent at latitude 62 degrees south to the Ellsworth Mountains at latitude 79 degrees. It became clear that areas more frequently visited by people are more affected by dirt and melt: places close to research stations or places that are often visited by tourism expeditions. Researchers estimate that around 53,000 tourists visited Antarctica between 2016 and 2020. This would mean that 83 tons of snow would have melted per tourist per year.
In fact, global pollution from power plant chimneys, car exhaust fumes or fires is not the main source of soot particles on the southern continent, because the wind systems around Antarctica rarely carry them far enough southwards in large quantities. Local dirt, on the other hand, remains on the continent: the winds blow dirt from ice-free regions in the north-east onto the ice surfaces; but most importantly, a lot of soot is deposited near stations like Palmer Station, McMurdo Dry Valley Field Stations, and the Amundsen-Scott South Pole Station. The stations near the coast in particular also receive many visits from tourists, which increases the environmental impact.