Antarctica

Antarctica is starting to look a lot like Greenland—and that isn’t good

Antarctica, climate change, glaciers, global warming, Science, syndication / 9u50fv / October 16, 2025

Global warming is awakening sleeping giants of ice at the South Pole.

A view of the Shoesmith Glacier on Horseshoe Island on Feb. 21. Credit: Sebnem Coskun/Anadolu via Getty Images

As recently as the 1990s, when the Greenland Ice Sheet and the rest of the Arctic region were measurably thawing under the climatic blowtorch of human-caused global warming, most of Antarctica’s vast ice cap still seemed securely frozen.

But not anymore. Physics is physics. As the planet heats up, more ice will melt at both poles, and recent research shows that Antarctica’s ice caps, glaciers, and floating ice shelves, as well as its sea ice, are just as vulnerable to warming as the Arctic.

Both satellite data and field observations in Antarctica reveal alarming signs of a Greenland-like meltdown, with increased surface melting of the ice fields, faster-moving glaciers, and dwindling sea ice. Some scientists are sounding the alarm, warning that the rapid “Greenlandification” of Antarctica will have serious consequences, including an accelerated rise in sea levels and significant shifts in rainfall and drought patterns.

The Antarctic ice sheet covers about 5.4 million square miles, an area larger than Europe. On average, it is more than 1 mile thick and holds 61 percent of all the fresh water on Earth, enough to raise the global average sea level by about 190 feet if it all melts. The smaller, western portion of the ice sheet is especially vulnerable, with enough ice to raise sea level more than 10 feet.

Thirty years ago, undergraduate students were told that the Antarctic ice sheets were going to be stable and that they weren’t going to melt much, said Ruth Mottram, an ice researcher with the Danish Meteorological Institute and lead author of a new paper in Nature Geoscience that examined the accelerating ice melt and other similarities between changes in northern and southern polar regions.

“We thought it was just going to take ages for any kind of climate impacts to be seen in Antarctica. And that’s really not true,” said Mottram, adding that some of the earliest warnings came from scientists who saw collapsing ice shelves, retreating glaciers, and increased surface melting in satellite data.

One of the early warning signs was the rapid collapse of an ice shelf along the narrow Antarctic Peninsula, which extends northward toward the tip of South America, said Helen Amanda Fricker, a geophysics professor with the Scripps Institute of Oceanography Polar Center at the University of California, San Diego.

Chunks of sea ice on the shore — Stranded remnants of sea ice along the Antarctic Peninsula are a reminder that much of the ice on the frozen continent around the South Pole is just as vulnerable to global warming as Arctic ice, where a long-term meltdown is well underway. Credit: Bob Berwyn/Inside Climate News

After a string of record-warm summers riddled the floating Rhode Island-sized slab of ice with cracks and meltwater ponds, it crumbled almost overnight. The thick, ancient ice dam was gone, and the seven major outlet glaciers behind it accelerated toward the ocean, raising sea levels as their ice melted.

“The Larsen B ice shelf collapse in 2002 was a staggering event in our community,” said Fricker, who was not an author of the new paper. “We just couldn’t believe the pace at which it happened, within six weeks. Basically, the ice shelves are there and then, boom, boom, boom, a series of melt streams and melt ponds. And then the whole thing collapsed, smattered into smithereens.”

Glaciologists never thought that events would happen that quickly in Antarctica, she said.

Same physics, same changes

Fricker said glaciologists thought of changes in Antarctica on millennial timescales, but the ice shelf collapse showed that extreme warming can lead to much more rapid change.

Current research focuses on the edges of Antarctica, where floating sea ice and relatively narrow outlet glaciers slow the flow of the ice cap toward the sea. She described the Antarctic Ice Sheet as a giant ice reservoir contained by a series of dams.

“If humans had built those containment structures,” she said, “we would think that they weren’t very adequate. We are relying on those dams to hold back all of that ice, but the dams are weakening all around Antarctica and releasing more ice into the ocean.”

Satellite view of ice cap coverage — A comparison of the average concentration of Antarctic sea ice. Credit: NASA Earth Observatory

The amount of ice that’s entered the ocean has increased fourfold since the 1990s, and she said, “We’re on the cusp of it becoming a really big number… because at some point, there’s no stopping it anymore.”

The Antarctic Ice Sheet is often divided into three sectors: the East Antarctic Ice Sheet, the largest and thickest; the West Antarctic Ice Sheet; and the Antarctic Peninsula, which is deemed the most vulnerable to thawing and melting.

Mottram, the new paper’s lead author, said a 2022 heatwave that penetrated to the coldest interior part of the East Antarctic Ice Sheet may be another sign that the continent is not as isolated from the rest of the global climate system as once thought. The extraordinary 2022 heatwave was driven by an atmospheric river, or a concentrated stream of moisture-laden air. Ongoing research “shows that there’s been an increase in the number of atmospheric rivers and an increase in their intensity,” she said.

Antarctica is also encircled by a powerful circumpolar ocean current that has prevented the Southern Ocean from warming as quickly as other ocean regions. But recent climate models and observations show the buffer is breaking down and that relatively warmer waters are starting to reach the base of the ice shelves, she said.

New maps detailing winds in the region show that “swirls of air from higher latitudes are dragging in all the time, so it’s not nearly as isolated as we were always told when we were students,” she said.

Ice researcher Eric Rignot, an Earth system science professor at the University of California, Irvine, who did not contribute to the new paper, said via email that recent research on Antarctica’s floating ice shelves emphasizes the importance of how the oceans and ice interact, a process that wasn’t studied very closely in early Greenland research. And Greenland shows what will happen to Antarctic glaciers in a warmer climate with more surface melt and more intense ice-ocean interactions, he added.

“We learn from both but stating that one is becoming the other is an oversimplification,” he said. “There is no new physics in Greenland that does not apply to Antarctica and vice versa.”

Rignot said the analogy between the two regions also partly breaks down because Greenland is warming up at two to three times the global average, “which has triggered a slowing of the jet stream,” with bigger wobbles and “weird weather patterns” in the Northern Hemisphere.

Antarctica is warming slightly less than the global average rate, according to a 2025 study, and the Southern Hemisphere jet stream is strengthening and tightening toward the South Pole, “behaving completely opposite,” he said.

Mottram said her new paper aims to help people understand that Antarctica is not as remote or isolated as often portrayed, and that what happens there will affect the rest of the global climate system.

“It’s not just this place far away that nobody goes to and nobody understands,” she said. “We actually understand quite a lot of what’s going on there. And so I also hope that it drives more urgency to decarbonize, because it’s very clear that the only way we’re going to get out of this problem is bringing our greenhouse gases down as much as possible, as soon as possible.”

This story originally appeared on Inside Climate News.

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Penguin poop may help preserve Antarctic climate

Antarctica, Arctic, Penguins, poop, poop talk, Science, syndication / Shannon Garcia / May 24, 2025

Ammonia aerosols from penguin guano likely play a part in the formation of heat-shielding clouds.

This article originally appeared on Inside Climate News, a nonprofit, non-partisan news organization that covers climate, energy, and the environment. Sign up for their newsletter here.

New research shows that penguin guano in Antarctica is an important source of ammonia aerosol particles that help drive the formation and persistence of low clouds, which cool the climate by reflecting some incoming sunlight back to space.

The findings reinforce the growing awareness that Earth’s intricate web of life plays a significant role in shaping the planetary climate. Even at the small levels measured, the ammonia particles from the guano interact with sulfur-based aerosols from ocean algae to start a chemical chain reaction that forms billions of tiny particles that serve as nuclei for water vapor droplets.

The low marine clouds that often cover big tracts of the Southern Ocean around Antarctica are a wild card in the climate system because scientists don’t fully understand how they will react to human-caused heating of the atmosphere and oceans. One recent study suggested that the big increase in the annual global temperature during 2023 and 2024 that has continued into this year was caused in part by a reduction of that cloud cover.

“I’m constantly surprised at the depth of how one small change affects everything else,” said Matthew Boyer, a coauthor of the new study and an atmospheric scientist at the University of Helsinki’s Institute for Atmospheric and Earth System Research. “This really does show that there is a deep connection between ecosystem processes and the climate. And really, it’s the synergy between what’s coming from the oceans, from the sulfur-producing species, and then the ammonia coming from the penguins.”

Climate survivors

Aquatic penguins evolved from flying birds about 60 million years ago, shortly after the age of dinosaurs, and have persisted through multiple, slow, natural cycles of ice ages and warmer interglacial eras, surviving climate extremes by migrating to and from pockets of suitable habitat, called climate refugia, said Rose Foster-Dyer, a marine and polar ecologist with the University of Canterbury in New Zealand.

A 2018 study that analyzed the remains of an ancient “super colony” of the birds suggests there may have been a “penguin optimum” climate window between about 4,000 and 2,000 years ago, at least for some species in some parts of Antarctica, she said. Various penguin species have adapted to different habitat niches and this will face different impacts caused by human-caused warming, she said.

Foster-Dyer has recently done penguin research around the Ross Sea, and said that climate change could open more areas for land-breeding Adélie penguins, which don’t breed on ice like some other species.

“There’s evidence that this whole area used to have many more colonies … which could possibly be repopulated in the future,” she said. She is also more optimistic than some scientists about the future for emperor penguins, the largest species of the group, she added.

“They breed on fast ice, and there’s a lot of publications coming out about how the populations might be declining and their habitat is hugely threatened,” she said. “But they’ve lived through so many different cycles of the climate, so I think they’re more adaptable than people currently give them credit for.”

In total, about 20 million breeding pairs of penguins nest in vast colonies all around the frozen continent. Some of the largest colonies, with up to 1 million breeding pairs, can cover several square miles.There aren’t any solid estimates for the total amount of guano produced by the flightless birds annually, but some studies have found that individual colonies can produce several hundred tons. Several new penguin colonies were discovered recently when their droppings were spotted in detailed satellite images.

A few penguin colonies have grown recently while others appear to be shrinking, but in general, their habitat is considered threatened by warming and changing ice conditions, which affects their food supplies. The speed of human-caused warming, for which there is no precedent in paleoclimate records, may exacerbate the threat to penguins, which evolve slowly compared to many other species, Foster-Dyer said.

“Everything’s changing at such a fast rate, it’s really hard to say much about anything,” she said.

Recent research has shown how other types of marine life are also important to the global climate system. Nutrients from bird droppings help fertilize blooms of oxygen-producing plankton, and huge swarms of fish that live in the middle layers of the ocean cycle carbon vertically through the water, ultimately depositing it in a generally stable sediment layer on the seafloor.

Tricky measurements

Boyer said the new research started as a follow-up project to other studies of atmospheric chemistry in the same area, near the Argentine Marambio Base on an island along the Antarctic Peninsula. Observations by other teams suggested it could be worth specifically trying to look at ammonia, he said.

Boyer and the other scientists set up specialized equipment to measure the concentration of ammonia in the air from January to March 2023. They found that, when the wind blew from the direction of a colony of about 60,000 Adélie penguins about 5 miles away, the ammonia concentration increased to as high as 13.5 parts per billion—more than 1,000 times higher than the background reading. Even after the penguins migrated from the area toward the end of February, the ammonia concentration was still more than 100 times as high as the background level.

“We have one instrument that we use in the study to give us the chemistry of gases as they’re actually clustering together,” he said.

“In general, ammonia in the atmosphere is not well-measured because it’s really difficult to measure, especially if you want to measure at a very high sensitivity, if you have low concentrations like in Antarctica,” he said.

Penguin-scented winds

The goal was to determine where the ammonia is coming from, including testing a previous hypothesis that the ocean surface could be the source, he said.

But the size of the penguin colonies made them the most likely source.

“It’s well known that sea birds give off ammonia. You can smell them. The birds stink,” he said. “But we didn’t know how much there was. So what we did with this study was to quantify ammonia and to quantify its impact on the cloud formation process.”

The scientists had to wait until the wind blew from the penguin colony toward the research station.

“If we’re lucky, the wind blows from that direction and not from the direction of the power generator,” he said. “And we were lucky enough that we had one specific event where the winds from the penguin colony persisted long enough that we were actually able to track the growth of the particles. You could be there for a year, and it might not happen.”

The ammonia from the guano does not form the particles but supercharges the process that does, Boyer said.

“It’s really the dimethyl sulfide from phytoplankton that gives off the sulfur,” he said. “The ammonia enhances the formation rate of particles. Without ammonia, sulfuric acid can form new particles, but with ammonia, it’s 1,000 times faster, and sometimes even more, so we’re talking up to four orders of magnitude faster because of the guano.”

This is important in Antarctica specifically because there are not many other sources of particles, such as pollution or emissions from trees, he added.

“So the strength of the source matters in terms of its climate effect over time,” he said. “And if the source changes, it’s going to change the climate effect.”

It will take more research to determine if penguin guano has a net cooling effect on the climate. But in general, he said, if the particles transport out to sea and contribute to cloud formation, they will have a cooling effect.

“What’s also interesting,” he said, “is if the clouds are over ice surfaces, it could actually lead to warming because the clouds are less reflective than the ice beneath.” In that case, the clouds could actually reduce the amount of heat that brighter ice would otherwise reflect away from the planet. The study did not try to measure that effect, but it could be an important subject for future research, he added.

The guano effect lingers even after the birds leave the breeding areas. A month after they were gone, Boyer said ammonia levels in the air were still 1,000 times higher than the baseline.

“The emission of ammonia is a temperature-dependent process, so it’s likely that once wintertime comes, the ammonia gets frozen in,” he said. “But even before the penguins come back, I would hypothesize that as the temperature warms, the guano starts to emit ammonia again. And the penguins move all around the coast, so it’s possible they’re just fertilizing an entire coast with ammonia.”

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Greening of Antartica shows how climate change affects the frozen continent

Antarctica, climate change, Science, syndication / Mike M. / October 6, 2024

Plant growth is accelerating on the Antarctic Peninsula and nearby islands.

Moss and rocks cover the ground on Robert Island in Antarctica. Photographer: Isadora Romero/Bloomberg Credit: Bloomberg via Getty

When satellites first started peering down on the craggy, glaciated Antarctic Peninsula about 40 years ago, they saw only a few tiny patches of vegetation covering a total of about 8,000 square feet—less than a football field.

But since then, the Antarctic Peninsula has warmed rapidly, and a new study shows that mosses, along with some lichen, liverworts and associated algae, have colonized more than 4.6 square miles, an area nearly four times the size of New York’s Central Park.

The findings, published Friday in Nature Geoscience, based on a meticulous analysis of Landsat images from 1986 to 2021, show that the greening trend is distinct from natural variability and that it has accelerated by 30 percent since 2016, fast enough to cover nearly 75 football fields per year.

Greening at the opposite end of the planet, in the Arctic, has been widely studied and reported, said co-author Thomas Roland, a paleoecologist with the University of Exeter who collects and analyzes mud samples to study environmental and ecological change. “But the idea,” he said, “that any part of Antarctica could, in any way, be green is something that still really jars a lot of people.”

illustration of Antarctica and satellite photos — Credit: Inside Climate News

As the planet heats up, “even the coldest regions on Earth that we expect and understand to be white and black with snow, ice, and rock are starting to become greener as the planet responds to climate change,” he said.

The tenfold increase in vegetation cover since 1986 “is not huge in the global scheme of things,” Roland added, but the accelerating rate of change and the potential ecological effects are significant. “That’s the real story here,” he said. “The landscape is going to be altered partially because the existing vegetation is expanding, but it could also be altered in the future with new vegetation coming in.”

In the Arctic, vegetation is expanding on a scale that affects the albedo, or the overall reflectivity of the region, which determines the proportion of the sun’s heat energy that is absorbed by the Earth’s surface as opposed to being bounced away from the planet. But the spread of greenery has not yet changed the albedo of Antarctica on a meaningful scale because the vegetated areas are still too small to have a regional impact, said co-author Olly Bartlett, a University of Hertfordshire researcher who specializes in using satellite data to map environmental change.

“The real significance is about the ecological shift on the exposed land, the land that’s ice-free, creating an area suitable for more advanced plant life or invasive species to get a foothold,” he said.

Bartlett said Google Earth Engine enabled the scientists to process a massive amount of data from the Landsat images to meet a high standard of verification of plant growth. As a result, he added, the changes they reported may actually be conservative.

“It’s becoming easier for life to live there,” he said. “These rates of change we’re seeing made us think that perhaps we’ve captured the start of a more dramatic transformation.”

In the areas they studied, changes to the albedo could have a small local effect, Roland said, as more land free of reflective ice “can feed into a positive feedback loop that creates conditions that are more favorable for vegetation expansion as well.”

Antarctic forests at similar CO₂ levels

Other research, including fossil studies, suggests that beech trees grew on Antarctica as recently as 2.5 million years ago, when carbon dioxide levels in the atmosphere were similar to today, another indicator of how unchecked greenhouse gas emissions can rapidly warm Earth’s climate.

Currently, there are only two species of flowering plants native to the Antarctic Peninsula, Antarctic hair grass, and Antarctic pearlwort. “But with a few new grass seeds here and there, or a few spores, and all of a sudden, you’ve got a very different ecosystem,” he said.

And it’s not just plants, he added. “Increasingly, we’re seeing evidence that non-native insect life is taking hold in Antarctica. And that can dramatically change things as well.”

The study shows how climate warming will shake up Antarctic ecosystems, said conservation scientist Jasmine Lee, a research fellow with the British Antarctic Survey who was not involved in the new study.

“It is clear that bank-forming mosses are expanding their range with warmer and wetter conditions, which is likely facilitating similar expansions for some of the invertebrate communities that rely on them for habitat,” she said. “At the same time, some specialist species, such as the more dry-loving mosses and invertebrates, might decline.”

She said the new study is valuable because it provides data across a broad region showing that Antarctic ecosystems are already rapidly altering and will continue to do so as climate change progresses.

“We focus a lot on how climate change is melting ice sheets and changing sea ice,” she said. “It’s good to also highlight that the terrestrial ecosystems are being impacted.”

The study shows climate impacts growing in “regions previously thought nearly immune to the accelerated warming we’re seeing today,” said climate policy expert Pam Pearson, director of the International Cryosphere Climate Initiative.

“It’s as important a signal as the loss of Antarctic sea ice over the past several years,” she said.

The new study identified vegetative changes by comparing the Landsat images at a resolution of 300-square-feet per pixel, detailed enough to accurately map vegetative growth, but it didn’t identify specific climate change factors that might be driving the expansion of plant life.

But other recent studies have documented Antarctic changes that could spur plant growth, including how some regions are affected by warm winds and by increasing amounts of rain from atmospheric rivers, as well as by declining sea ice that leads adjacent land areas to warm, all signs of rapid change in Antarctica.

Roland said their new study was in part spurred by previous research showing how fast patches of Antarctic moss were growing vertically and how microbial activity in tiny patches of soil was also accelerating.

“We’d taken these sediment cores, and done all sorts of analysis, including radiocarbon dating … showing the growth in the plants we’d sampled increasing dramatically,” he said.

Those measurements confirmed that the plants are sensitive to climate change, and as a next step, researchers wanted to know “if the plants are growing sideways at the same dramatic rate,” he said. “It’s one thing for plants to be growing upwards very fast. If they’re growing outwards, then you know you’re starting to see massive changes and massive increases in vegetation cover across the peninsula.”

With the study documenting significant horizontal expansion of vegetation, the researchers are now studying how recently deglaciated areas were first colonized by plants. About 90 percent of the glaciers on the Antarctic Peninsula have been shrinking for the past 75 years, Roland said.

“That’s just creating more and more land for this potentially rapid vegetation response,” he said. “So like Olly says, one of the things we can’t rule out is that this really does increase quite dramatically over the next few decades. Our findings raise serious concerns about the environmental future of the Antarctic Peninsula and of the continent as a whole.”