How Climate Change Is Turning Antarctica Green

When you think of Antarctica, plants probably aren't the first things that come to mind. After all, Earth's icy southernmost continent is the largest desert in the world, not only bitterly cold but exceptionally dry; there are places in Antarctica that haven't seen liquid water for millions of years. All the same, Antarctica does have a few unique plant species all of its own, and in recent years, they've been thriving.

Climate change is dramatically altering the polar climate, and with record-low levels of ice, Antarctica's flowering plants are spreading at unprecedented rates. Only two species of complex, flowering plants call the continent home, but a warming climate is allowing them to expand. While most of Antarctica is still blanketed by a permanent layer of ice and snow, plants can now be found growing in places that were once thought completely inhospitable to them.

Of all of climate change's effects over the past decade, the thriving plants in Antarctica are one of the most pronounced — and alarming. But as a place with no permanent human residents, the entire continent remains out of most people's view, so many of us are unaware of how much it's changing. A study published in Current Biology explains this in some detail, describing how the continued warming is leading to more ice-free areas, leading to a "striking expansion" in the amount of area covered by plants. Researchers think it's mostly driven by warmer air over the continent during summer.

Climate change has been steadily making its effects known worldwide, but the Antarctic is being hit hardest of all. As Discovering Antarctica explains, over the last half-century, Earth's south polar region has warmed more dramatically than anywhere else. The temperature there is currently rising five times as fast as the rest of the world, affecting the temperatures both on land and in the sea. This includes the Antarctic Circumpolar Current — a huge swirling vortex of water in the Southern Ocean that encircles the entire continent of Antarctica. As it circulates, it distributes heat and helps to keep Antarctica frozen. This disruption means that Earth's coldest continent is steadily becoming warm enough for plants there to grow extensively, with the potential for the continent to become greener than it has been for millions of years.

All of this also spells trouble for the rest of the world. More land for plants to grow on also means less ice, and less ice carries the threat of dramatically rising sea levels. Alarmingly, Antarctica has been warming far quicker than scientists predicted. One part of the continent where the ice has been melting at an alarming rate is the Antarctic Peninsula, a region where coastal ice shelves have been gradually disappearing, leaving glaciers unprotected. This is also the region where most of Antarctica's plants can be found, with most of the continent's more hospitable, ice-free land.

While there may be nothing resembling true grasslands in Antarctica, it does have a single native grass species. Antarctic hair grass (Deschampsia antarctica) grows in small green tufts and is usually found in rough, rocky areas. As a grass, it can withstand being trampled on, and it tends to grow in the places where Antarctic animals can be found. Hair grass can even survive being pummelled by elephant seals, and tends to grow abundantly around penguin colonies, where it has ample amounts of fertilizer.

Antarctica's only grass has a few tricks to help it survive in the frigid environment. For one thing, it has a deep and complex root system, helping it find enough water and nutrients while also helping it stand up to the stormy polar environment. In winter, its roots become even more essential. To survive the cold, it loses all of its leaves, finding safety below the soil.

The roots of the Antarctic hair grass are the key to its survival, but they also pose a risk to Antarctic ecosystems. In the barren soil, plants need to be experts at harvesting nutrients, and this grass is adapted to be extremely efficient at taking in nitrogen. As the climate continues to warm, however, this also means that the grasses can easily outcompete mosses and other local species. Nitrogen is scarce in the polar soil, so if the grass takes up too much, there may not be enough left to go around.

Antarctica's ecosystems are unique in the world. Most places in the world are completely dominated by vascular plants — the complex plants we're all familiar with, with roots, stems, leaves, and systems to circulate nutrients throughout their bodies. Antarctica, per a paper in the journal WIREs, is instead dominated by simple plants like mosses, and species that aren't true plants at all, like lichens and algae. The harsh Antarctic environment allows these simpler species, collectively known as non-vascular vegetation, to shine.

The delicate ecosystems of Antarctica are extremely sensitive to change. The biggest driving force of that change is air temperature, and summer air around the South Pole has been steadily warming. The changes in recent years have been so dramatic that even the climate scientists studying them have been surprised by what they've found. Per The Guardian, one lead researcher mentioned, "I was expecting an increase of these plants but not of this magnitude. We are receiving multiple evidences that a major change is occurring in Antarctica."

The cold climate is essentially the only thing that's been holding the more complex vascular plants back. As Antarctica warms, there's a chance they could start to drown out their simpler cousins. While no one's sure exactly what the long-term effects will be, it's certain those effects will be dramatic ones. A study in Current Biology mentions quite ominously, "future warming will trigger significant changes in these fragile Antarctic ecosystems."

Beneath the icy polar seas, the marine environment off the Antarctic coast is still not very well known. There's a lot of coastline and only limited opportunity to observe it directly. Technically, seaweeds aren't actually plants but algae, but they're essential to marine ecosystems, and new species of Antarctic seaweed are still being discovered growing in the freezing cold waters. A different kind of seaweed, however, is one of Antarctica's most concerning invasive species.

Wakame is best known as a tasty sea vegetable popularly used in Japanese cuisine. As an invasive species, however, it can be decidedly unsavory. Outside its native habitat, wakame grows prolifically, outcompeting local species and damaging biodiversity as a result. At the same time, though, it's not entirely predictable and can sometimes even have beneficial effects.

Invasive marine species can be difficult to prevent. They can easily arrive as hitchhikers on the hulls of any of the ships that visit Antarctica every year, but there are completely natural ways for invasive species to arrive too, and these are far more difficult to predict. Kelp rafts, patches of free-floating seaweed, can drift across long distances. They can be carried by ocean currents, and invasive seaweeds like wakame can easily arrive in new places this way, as passengers. While the cold Antarctic climate usually prevents these invaders from taking root, the warming seawater means that they're more likely to survive the journey, and will have an easier time getting established once they arrive.

Antarctica is usually seen as a pristine wilderness, mostly untouched by humanity. Unfortunately, that isn't really true anymore. Climate change is a global problem, and it's set to change Antarctica irreversibly. Climate models suggest that by the end of this century, the continent may have three times as much ice-free land as it currently does, and plants will rapidly take root on it. What's more, this may even be a conservative prediction. Scientists have a track record of underestimating how much Antarctica might change, and it's already been warming faster than models have predicted.

Sadly, it's likely the unique ecosystems of Antarctica are doomed. Global greenhouse gas emissions are higher than ever before, and are still continuing to increase. At this point, per a study published in Nature, the melting of the Antarctic ice is set to be "rapid and unstoppable." As sea levels rise and ice levels fall, more and more of Antarctica will become free to turn green.

Unfortunately, it's difficult to predict how exactly the southernmost part of the world might look in the future. Making accurate predictions requires background information, and researchers simply don't have enough to say anything with certainty. There's no way to know how Antarctica's flora may look in the future. Both native and invasive species will continue to grow, and it's likely that more invasive species will eventually arrive. As Antarctica's coasts slowly turn green, though, one thing can be almost guaranteed — it will never be the same again.