In a part of the world where throughout history only the pure white of snow and ice could be seen, today green moss and grass are emerging. Fish and penguins have begun to migrate south in search of colder regions. Even rain, an unthinkable phenomenon until recent times, now falls on this part of the planet. These are just a few of the signs that temperatures are rising in parts of Antarctica, and quickly.

“What most caught my attention are the shrinking glaciers and the increased areas of melted snow at their front edges, where a whole new set of organisms are now growing,” says Jefferson Cardia Simões from the Polar and Climate Center at the Federal University of Rio Grande do Sul (UFRGS) in Brazil. “It’s very striking because it’s evident at first glance.”

Simões is a professor at the university’s polar geography department and has visited Antarctica 27 times since 1990. He led the most recent expedition, which ran from November 2024 until January 2025 and is already recognized as the largest polar circumnavigation ever carried out. The team included 61 researchers from seven different countries and the trip covered 29,000 kilometers (18,000 miles) — about three-quarters the circumference of the globe.

The expedition ran 70 days on a Russian icebreaker, a ship that can cross through frozen seas and navigate near the glaciers surrounding the Antarctic. “Brazil has no icebreakers and there are very few of them available for scientific research worldwide,” says UFRGS geography professor Francisco Eliseu Aquino, who led the expedition’s climatology team. “With this ship, we were able to cross sheets of ice up to 1.5 meters [5 feet] thick and pull up close to the world’s largest glaciers.”

The expedition fully circumnavigated the continent of Antarctica, which is 1.6 times larger than Brazil, keeping as close as possible to the glaciers all the way around. The researchers collected samples of snow, ice, plants and microorganisms to be studied over the coming year and beyond.

Still, the visual observations made by the researchers were enough to conclude that climate change is already having devastating effects on Antarctica’s northernmost fringes, where Brazil’s Commander Ferraz Antarctic Station is located. These impacts, the researchers say, are reverberating throughout South America.

“Oceanic and atmospheric circulation exists because of the temperature difference between the tropics and the polar regions,” Simões says. “The processes affecting the polar regions affect the tropics, and vice versa. It is a single, undividable system.”

Global warming increases this difference in temperature between the poles and the tropics, intensifying the atmospheric currents. In Brazil, the effects are periodically hotter and drier in its Central and North regions — which suffered the heaviest drought in recorded history last year, when river levels in the Amazon Rainforest dropped perilously low — and increased rainfall in the South region. “Antarctica plays a dominant role in the number and intensity of cyclones and cold weather fronts that hit Rio Grande do Sul state,” Aquino says.

There had already been two large floods in Rio Grande do Sul, Brazil’s southernmost state, in 2023. Just six months later, in May 2024, unprecedented rainfall led to the state’s severest climate tragedy, resulting in more than 180 deaths and 700,000 people forced from their homes. Some parts of the state capital, Porto Alegre, remained underwater for more than a month.

“Environmental degradation is creating conditions for the cold and hot polarization to intensify,” Aquino says. “This is why we can predict that we’ll see this phenomenon again within the next 30 years.”

Aside from climate repercussions, higher temperatures in Antarctica are contributing to rising sea levels, which place coastal towns at risk in Brazil and across the planet. In Australia, rising sea levels have already led the government to create a relocation plan for the population of an entire chain of islands.

One of the objectives of the team led by Brazil was to collect data on the melting rate of the Antarctic glaciers, which are approximately 500 m (1,640 ft) thick. More importantly, they also want to understand if these enormous masses of ice are moving more quickly toward the ocean.

According to Aquino, this could happen because of the frontal melting that happens where they meet with the ocean. Without resistance from the ice that has held its place in previous times, the ice located on the continent ends up sliding into the ocean. “The glacier will flow more quickly, melt in the ocean and sea levels will rise,” Aquino says.

Rising ocean temperatures are another factor worsening the situation. At some locations, warmer water flows under the ice platform and creates a layer of water that works as a lubricant, causing the glacier to slide more quickly toward the ocean. “This could cause sea levels to rise by 2 or 3 meters [6-10 ft] in the next 200 or 300 years,” Simões says.

The Antarctic is home to 90% of the planet’s ice, and the ocean surrounding it is warming faster than any other on the planet, followed by the Arctic. “The largest heat wave recorded on Earth in recent years was in Antarctica in 2022,” Aquino says. “It was so unexpected that it really frightened us. The temperature was 40 degrees [Celsius, or 72° Fahrenheit] higher than expected temperatures for that time of the year.”

The researcher also found microplastics and soot in the Antarctic snow samples collected. One of the hypotheses is that the material came from wildfires in the Amazon and were carried to Antarctica by an atmospheric river — the same phenomenon that blanketed a number of Brazilian cities in smoke in 2024.

Banner image: Scientists collected samples of ice, snow, plants and microorganisms to understand how Antarctica is reacting to climate change. Image courtesy of Anderson Astor and Marcelo Curia/ICCE.

This story was first published here in Portuguese on March 7, 2025.