A new study said that Antarctica is covering with moss due to global warming. The moss banks, which can be found across parts of the western Antarctic Peninsula, have been growing dramatically over the past 50 years.

The new findings were published in the journal Current Biology on May 18. Tom Roland, one of the co-authors of the study, reported that moss has increased by four o five times in the past five decades. Researchers said that moss is increasingly growing because of climate change, as they found evidence that some moss species that once grew less than a millimeter per year are now growing over 3 millimeters per year on average.

Moss in Antarctica
A lush moss bed at Casey. Image credit: Sharon Robinson.

Moss is growing rapidly across the now green Antarctic Peninsula

The researchers, from the University of Exeter, the University of Cambridge, the British Antarctic Survey and the University of Durham, noted that higher temperatures and less ice are likely going to open up more land for the moss ecosystems to expand into.

Moss in Antarctica
A bank of moss on the Antarctic Peninsula. Image credit: Matt Amesbury.

“People think of Antarctica quite rightly as a very icy place, but our work shows that parts of it are green, and are likely to be getting greener,” said Matthew Amesbury, a scientist with the University of Exeter, and lead author of the new study, according to The Washington Post. “Even these relatively remote ecosystems, that people might think are relatively untouched by human kind, are showing the effects of human induced climate change.”

Antarctica has less than 1 percent of plant life, according to the researchers. However, in parts of the peninsula, Antarctic mosses grow on frozen ground that partly thaws during the summer, when only around the first foot of soil ever thaws. The surface mosses build up in a thin layer during the summer and then freeze over in winter, and it goes on and on. As layers build on top of other layers, older mosses subside below the frozen ground, where they preserve correctly due to the icy temperatures.

Researchers took soil samples from a 400-mile area in the northern part of the Antarctic Peninsula and found dramatic changes in growth patterns dating back 150 years. The Antarctic Peninsula has been an area of rapid warming, as they sustain more days a year where temperatures rise above freezing. The researchers found that moss presence has grown four to five times in the most recent part of the reports.

“This is another indicator that Antarctica is moving backward in geologic time – which makes sense, considering atmospheric CO2 levels have already risen to levels that the hasn’t seen since the Pliocene, 3 million years ago, when the Antarctic ice sheet was smaller, and sea-levels were higher,” said Rob DeConto, a glaciologist at the University of Massachusetts who was not involved in the study, according to The Washington Post.

DeConto added that if greenhouse gas emissions continue unchecked, Antarctica will head even further back in geologic time. He believes Antarctica will even become forested again someday as it was during the greenhouse climates of the Cretaceous and Eocene, when the continent was ice free.

The authors noted that the currently observed moss growth changes are probably just the beginning. They wrote in the paper that the changes, combined with increased ice-free land areas from glacier retreat, will drive large-scale alteration to the biological functioning, appearance and landscape of the Antarctic Peninsula over the next years of the 21st century and beyond.

Moss growth is also happening in the Arctic

The moss growth is still modest compared to the one going on in the Arctic, where a large-scale greening trend has been captured by satellite. So many plants are growing now in the Arctic that scientists are hoping it will at least partially offset the loss of carbon from thawing permafrost beneath those plants. Those days are probably still very far off for the Antarctic, but researchers believe the continent used to be a very different landscape.

According to Amesbury, people are starting back on a journey toward that sort of environment, and that Antarctica has certainly not always been the ice planet it has been now on very long timescales.

Moss in Antarctica
The moss banks of Signy. Image credit: P. Boelen.

“I don’t see too much of a problem with regional moss species,” said Dominic Hodgson, one of the study’s co-author, according to CNN. “And there are also two grasses that have been found. But we need to be very careful about non-indigenous species of plants that risk being introduced.”

According to Hodgson, that has already happened in some parts of the sub-Antarctic islands, where non-indigenous species have been brought in by accident on the clothing and equipment of researchers.

Source: The Washington Post