Antarctica Greening Up as Climate Change Takes Hold

moss on Antarctica
Green moss and icebergs in Antarctica. (Photo: Matt Amesbury)

(CN) – Climate change is turning the white, frozen tundra of Antarctica a bit greener.

An international team of researchers say the trend is the result of the “greenhouse effect,” which is expanding plant growth on the continent. Their findings appeared Thursday in the journal Current Biology.

The scientists reviewed moss banks, finding that major biological changes had occurred over the past 50 years across the Antarctica Peninsula.

“If this continues, and with increasing amounts of ice-free land from continued glacier retreat, the Antarctic Peninsula will be a much greener place in the future,” said lead author Matt Amesbury, a researcher with the University of Exeter in the United Kingdom.

While weather records began in the 1950s, the moss bank presents biological records that can provide scientists a clear timeline of the effects of climate change.

The team reviewed data for the past 150 years, which revealed evidence of changepoints – points in time after which biological activity plainly increased – over the past half century.

“The sensitivity of moss growth to past temperature rises suggests that ecosystems will alter rapidly under future warming, leading to major changes in the biology and landscape of this iconic region,” said co-author Dan Charman, also from Exeter. “In short, we could see Antarctic greening to parallel well-established observations in the Arctic.

“Although there was variability within our data, the consistency of what we found across different sites was striking.”

The scientists say their data shows soils and plants will change dramatically even with only limited further warming. They plan to review core records that date back thousands of years in order to study the impact of climate change before humans contributed to global warming.

Increases in ice-free land also limit how much sunlight is reflected back into space, which results in more solar radiation being absorbed by the surrounding waters.

As this trend continues, Antarctica might begin to warm at a rate similar to that of the Arctic, which has warmed at a rate of about 1 degree Fahrenheit a decade over the past 30 years. The average temperature of Antarctica has risen about 0.33 degrees Fahrenheit over that period.

The stark differences in warming rates experienced at the poles primarily stem from average elevation, according to a separate study also published Thursday.

“I wondered why some of the reasons to explain Arctic warming have not yet caused strongly amplified warming in all of Antarctica as well,” said Marc Salzmann, the author of the study published in the journal Earth System Dynamics. “I thought that land height could be a game-changer that might help explain why the Arctic has thus far warmed faster than Antarctica.”

Antarctica is the tallest continent on Earth, with an average elevation of roughly 8,200 feet. Besides reflecting more solar radiation back to space, the continent’s landscape also affects how heat is transported in the atmosphere from the equator.

Salzmann ran simulations using a computer model of the Earth system, which showed that reducing Antarctica’s land height would cause it to warmer quicker.

“Assuming a flat Antarctica allows for more transport of warm air from lower attitudes,” he said. “This is consistent with the existing view that when the altitude of the ice is lowered, it becomes more prone to melting.”


%d bloggers like this: