The fifth-largest continent, the magical Antarctica, which dominates the South Pole in all its mysterious isolation, began to form as an ice sheet 34-35 million years ago.
The formation of this ice sheet was a result of a number of factors, predominantly the movement of continents, in what is known as the 'Continental Drift'. South America and Tasmania, which had been connected to Antarctica for millions of years, began drifting North.
Along with this, the opening of the Drake Passage, the strait between South America and Antarctica, allowed cold water to flow around Antarctica, which further isolated it from warm ocean currents and contributed to the formation of the ice sheet. Meanwhile, global temperatures had been steadily decreasing for 16 million years before the ice sheet formed, which further intensified the ecological situation Antarctica finds itself in today. Hence, it can be understood that under the ice sheet rests an expanse of green, frozen in time. Accordingly, scientists have theorised that before the ice sheet formed, Antarctica was more like Northern Canada today, where tundra and coniferous forests abound.
Global warming, with the inevitable climate change, have affected a host of natural environments and topographies across continents, with massive ice sheets and glaciers falling victim to these disruptive vagaries of nature, and melting away at an alarming rate. While this has been documented in the Arctic region, where the glaciers are disintegrating due to human activities that have raised temperatures, a similar trend is being observed in the Antarctic too. Vegetation cover across the Antarctic peninsula has increased ten-folds over the last four decades, largely due to its ice sheet warming faster than the global average, as extreme heat events fuelled by the global climate crisis rapidly engulfs the cold continent, new research shows, highlighting that the spread of plant life, predominantly mosses, has accelerated since 2016.
The new study, carried out by the universities of Exeter and Hertfordshire, and the British Antarctic Survey, used satellite data to assess how much the Antarctic peninsula has been “greening” in response to climate change. It found that the area of plant cover across the peninsula increased from less than 1 sq km in 1986, to almost 12 sq km by 2021. Satellite imagery also confirmed that the widespread greening trend, across the peninsula, is only accelerating.
Published in journal Nature Geoscience, the study paper – titled “Satellites evidence sustained greening of the Antarctic Peninsula" – also found that this greening trend accelerated by over 30% in recent years (2016-2021), relative to the full study period (1986-2021), expanding by over 400,000 sqm per year in this duration. In a previous study, which examined core samples taken from moss-dominated ecosystems on the Antarctic peninsula, the team found evidence of plant growth increasing dramatically in recent decades.
“The plants we find on the Antarctic peninsula – mostly mosses – grow in perhaps the harshest conditions on Earth,” says Dr Thomas Roland from the University of Exeter, adding, “The landscape is still almost entirely dominated by snow, ice and rock, with only a tiny fraction colonised by plant life... But that tiny fraction has grown dramatically, showing that even this vast and isolated wilderness is being affected by anthropogenic climate change.”
Dr Olly Bartlett from the University of Hertfordshire mentions: “As these ecosystems become more established, and the climate continues to warm, it’s likely that the extent of greening will increase.”
“Soil in Antarctica is mostly poor or non-existent, but this increase in plant life will add organic matter, and facilitate soil formation – potentially paving the way for other plants to grow. This raises the risk of non-native and invasive species arriving, possibly carried by eco-tourists, scientists or other visitors to the continent,” he warns. The researchers emphasise the urgent need for further research to establish the specific climate and environmental mechanisms that are driving the greening trend.
“The sensitivity of the Antarctic peninsula's vegetation to climate change is now clear and, under future anthropogenic warming, we could see fundamental changes to the biology and landscape of this iconic and vulnerable region,” says Dr Roland, who co-led the study.
He adds: “Our findings raise serious concerns about the environmental future of the Antarctic peninsula, and of the continent as a whole. In order to protect Antarctica, we must understand these changes and identify precisely what is causing them.” Accordingly, the researchers are now investigating how recently deglaciated (ice-free) landscapes are colonised by plants, and how the process might proceed into the future.
Rise in sea levels
The melting of Antarctica's ice sheets raises serious concerns, especially with the rise in sea levels. The Antarctic ice sheet contains enough ice (and fresh water) to raise global sea levels by 60 meters if it all melted. Already, each year, the sheet loses an average of 150 billion metric tons of ice, with the years between 2002 and 2017 alone noticing ice sheets contributing to a third of the total mean sea-level rise on the planet. A 2016 Nature study concluded that Antarctica could contribute more than a meter of sea-level rise by 2100, and more than 15 metres by 2500. A 2021 study also stated that if the world continues on its current emissions trajectory, the cold continent might experience a jolt in ice melt around 2060. The resultant sea-level rise would not only affect the Earth's natural cycles and biosphere at large, but significantly increase coastal flooding and eventually inundate coastal cities and communities.
Besides, it would also catastrophically disrupt life cycles of Antarctic fauna, such as penguins and seals, which will face habitat and food losses, leading to mass migrations or extinctions itself. Meanwhile, unusual patterns of greening have also been reported in the Arctic, such as in 2021 when rain, and not snow, fell on the summit of Greenland’s huge ice cap for the first time on record, indicating a drastic temperature shift. It's about time we turned down the heat!
Melting the facts
Antarctica is the Earth’s southern-most and least-populated continent, situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean
It is the fifth-largest continent, about 40% larger than Europe, and has an area of 14,200,000 sq km
Most of the continent is covered by the Antarctic ice sheet, with an average thickness of 1.9 km
It was in 1773 that Britain’s Captain James Cook became the first adventurer to enter Antarctica. In 1911, Norwegian explorer Roald Amundsen reached the South Pole
Antarctica is a polar desert, and is the coldest, driest, and windiest continent, with the highest average elevation of 2,500 metres
About 70% of the world’s freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost 60 metres
Antarctica holds the record for the lowest measured temperature on Earth, at −89.2°C
Native species of animals include mites, nematodes, penguins, seals and tardigrades. Vegetation occurs in the form of lichens or mosses
Antarctica is governed by about 30 countries, which are all parties of the 1959 Antarctic Treaty System
Military activity, mining, nuclear explosions, and nuclear waste disposal are prohibited in Antarctica, while tourism is permitted
Between 1,000 and 4,000 scientists work on the continent, across 70 research stations, round the year
Green cover that’s not good
The greening of Antarctica is a sign of global heating, which is warming the continent faster than the global average. This has several negative implications:
It could lead to more soil formation, which could make the region ground for invasive species that could harm local wildlife
Since darker plants absorb more heat, it could reduce Antarctica’s ability to reflect sunlight
It could alter the region’s ecosystem dynamics, potentially affecting soil composition, carbon cycles, and local food webs
It could lead to fundamental changes to the biology and landscape of the region
The largest ice shelf on Earth, roughly the size of France, the Ross ice shelf is melting 10 times faster than average too