University of Cambridge | Matt Davey

Green Snow In Antarctica Has Researchers Eyeing Climate Change

There are many certainties in life, more even than just death and taxes: The sun always manages to rise even after the darkest night, gravity keeps us all nicely on the ground, and April showers still bring May flowers.

However, one of the certainties we thought we had about life on Earth is changing - we once thought Antarctica would always remain a pristine, white, wintry landscape, home to penguins and little else, and now it's turning green.

Researchers with the University of Cambridge have been studying the greening of Antarctica and found that it's spreading rapidly due to climate change.

Nature

The green isn't grass, but microscopic algae sitting on the snow's surface.

Patches of green algae have been visible around the continent's coast for some time, but the research team spent two years mapping the extent of the algae blooming on the Antarctic peninsula and say that they expect the areas to spread more as temperatures continue to rise, creating ideal conditions for algae to thrive.

The areas with green snow are already large enough to be observed from space.

University of Cambridge | Monika Mendelova

Indeed, the researchers used both satellite data and ground observations to make their map of the algae. They found that the warmer areas tended to grow more algae, especially when penguin and other animal colonies were nearby as their waste acts as fertilizer.

While all that algae is turning Antarctica's white snow green, it's also eating up carbon dioxide.

University of Cambridge | Sarah Vincent

The researchers said that they found 1,679 separate algae blooms in all, which covered a total area of about 1.9 square kilometers.

That amounts to a carbon sink of about 479 tons per year, the equivalent of 875,000 car trips on the U.K. However, while the algae absorbs more carbon dioxide, it also darkens the snow, meaning that it reflects less sunlight.

And the researchers expect to see a lot more algae on Antarctica in the future.

University of Cambridge | Matt Davey

"As Antarctica warms, we predict the overall mass of snow algae will increase, as the spread to higher ground will significantly outweigh the loss of small island patches of algae," said co-lead author of the study Dr. Andrew Gray.

The mapping the team has done provides a baseline to see how much the algae spreads in the future, and how quickly.

What that will mean for the continent and the wildlife already living there remains to be seen, however.

But the researcher said that they could already see bacteria and fungi forming bonds with the algae. "It’s a community. This could potentially form new habitats. In some place, it would be the beginning of a new ecosystem," said co-lead author Dr. Matt Davey.

"This is a significant advance in our understanding of land-based life on Antarctica, and how it might change in the coming years as the climate warms."

The research team's study was published in the journal Nature.

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