From tourism to research activities, humans are leaving a mark in Antarctica – and not a very good one. A new study found that black carbon pollution from human activities in Antarctica is likely increasing snowmelt by about 83 tons per visitor. The remote continent is already one of the places in the world most affected by man-made global warming, experiencing almost 3ºC (5.4 Fahrenheit) of warming in the past 50 years, much higher than the global average of 0.9ºC (1.6 Fahrenheit).
Every summer, tourists and scientists flock to Antarctica by boat and plane. What used to be a very remote continent is now becoming much more accessible. There are more than 70 research stations housing thousands of researchers. During the 2019-2020 season, the number of tourists reached 74,000, with most of them traveling by ship.
As you can imagine, this is leaving a physical mark with lasting consequences. While trash and human waste are flown or shipped off the continent for disposal, some forms of waste are not too easily removed. Every activity in Antarctica uses fuel. As we burn it, human activities release microscopic particles of what’s known as black carbon.
Black carbon is mostly produced during combustion in engines, wildfires, coal burning, and residential wood burning. While it stays in the atmosphere for a limited period of time, it can be transported regionally or intercontinentally. As a result, it has been found in snow samples in the Arctic, North America, the Andes, and Antarctica.
In a new study, researchers sampled the snow yearly between 2016 and 2020 at 28 sites in Antarctica – going from the Ellsworth Mountains to the continent’s northern tip. They focused on the Antarctic peninsula, as that’s where half of the research facilities are currently located and also where over 95% of the tourist trips are made.
“The black carbon footprint of local activities in Antarctica has likely increased as human presence in the continent has surged. Vessels, airplanes, diesel power plants, generators, helicopters, and trucks are all local black carbon-rich sources that affect snow several kilometers downwind,” the researchers wrote in the journal Nature.
Black carbon and snowmelt
In their study, the researcher analyzed the quantity and type of light-absorbing particles in snow samples. These were passed through filters and analyzed for their optical properties so to identify the type of particulates. There are many types of impurities that absorb light in Antarctic snow but in very minuscule quantities.
All samples obtained near human housing had black carbon levels above the usual Antarctic levels – a sign of human emissions. High levels of black carbon influence how the snow absorbs light, known as albedo. Snow with a lower albedo melts faster. The black carbon content in the snow samples could then be used to estimate if snowmelt increased due to human activity.
Human-produced black carbon could be causing surface snow to melt by up to 23 millimeters every summer. When looking at tourism specifically, the study found that every visitor between 2016 and 2020 was melting 83 tons of snow due to emissions from cruise ships. Scientific activities are also contributing their fair share due to the use of equipment and vehicles.
Mechanisms to mitigate black carbon impacts are needed, the researchers argued. They called for global agencies to limit tourism while pushing for a faster transition to clean fuel and hybrid or electric ships. Simultaneously, the size and footprint of research facilities should be addressed by adopting renewable energy power plants and energy efficiency standards.
Pine Island is Antarctica’s biggest glacier and also the fastest melting one on the continent, responsible for about 25% of its total ice loss. Now, in a new study, researchers showed that the glacier is more vulnerable to rapid melting than previously thought, as climate change is weakening its natural braking system.
Together with its neighboring Thwaites glacier, Pine Island connects the center of the western Antarctic ice sheet with the ocean, discharging significant amounts of ice to the sea. These two glaciers have been losing ice for the past 25 years. If this speeds up, global seas could rise significantly over the next few centuries, scientists estimate.
“We may not have the luxury of waiting for slow changes on Pine Island; things could actually go much quicker than expected,” lead author Ian Joughin, said in a statement. “The processes we’d been studying in this region were leading to an irreversible collapse, but at a fairly measured pace. Things could be much more abrupt if we lose the rest of that ice shelf.”
The Pine Island and Thwaites glaciers have been under the spotlight in recent decades as their ice shelves thinned because warmer ocean currents melted the ice’s underside. Pine Island Glacier’s motion toward the sea accelerated from 2.5 kilometers per year in the 1990s to 4 kilometers per year to 2009. The speed then stabilized for almost a decade but is now accelerating.
Pine Island’s ice shelf lost one-fifth of its area in a few dramatic breaks from 2017 to 2020, captured by the Copernicus Sentinel-1 satellites, operated by the European Space Agency. This created icebergs more than eight kilometers long and 36 kilometers wide, which then split into lots of little pieces, Joughin told Associated Press.
Alongside scientists from the University of Washington and British Antarctic Survey, Joughin combined satellite data with a computer model of ice movement to determine what is driving the speed up. Due to its extremely remote location, satellites play a fundamental role in the measurement and monitoring of Antarctic glaciology.
The researchers found that the glacier’s ice shelf has retreated by 20 kilometers between 2017 and 2020. This was caught on time-lapse video from a European satellite that takes pictures every six days. The ice shelf seems to be “ripping itself apart” because of the glacier’s acceleration in the past two decades, Joughin explained.
“The recent changes in speed are not due to melt-driven thinning; instead they’re due to the loss of the outer part of the ice shelf,” Joughin said in a statement. “The glacier’s speedup is not catastrophic at this point. But if the rest of that ice shelf breaks up and goes away then this glacier could speed up quite a lot.
For the researchers, it’s not clear yet whether the shelf will continue to crumble or no, as other factors, such as the slope of the land below the glacier’s receding edge, will also influence the outcome. But what’s certain is that the new findings change the timeline for when Pine Island’s ice shelf could disappear and the speed the glacier might move.
During yet another miserable, freezing day of fieldwork in Antarctica, geologist James Smith of the British Antarctic Survey dropped a super-long cable down a hole drilled through 900-meter-thick ice. The idea was to scoop some sediments from the seafloor below, a plan that utterly failed since the collection instrument hit a rock. But the cable also carried a GoPro camera, which stunned everyone who saw the footage. In it, they could see the rock was covered in something that should have had no business being there, namely life.
An accidental discovery of extreme life
Smith is no biologist, but he has colleagues at the British Antarctic Survey that are. When the entire team saw the footage showing a film on the rock, the biologists immediately recognized these must be lifeforms. Subsequent investigations showed 16 sponges, along with 22 yet unidentified animals, some of which look a lot like barnacles.
“This discovery is one of those fortunate accidents that pushes ideas in a different direction and shows us that Antarctic marine life is incredibly special and amazingly adapted to a frozen world,” says biogeographer and lead author, Dr. Huw Griffiths of British Antarctic Survey.
In 2017, scientists found a hidden ecosystem lurking 9.5 kilometers (6 miles) beneath the Mariana Trench — what may be the deepest traces of life on Earth. And although the water is extremely cold, oxygen is low, light is totally absent, and pressure can bubble up to hundreds of times that at sea level, approximately 25% of the estimated 8,700,000 species on Earth live in the ocean depths. So, what’s the big deal about discovering some tiny sponges under less than a kilometer of ice?
Although deep-sea creatures have to endure extreme conditions, lack of food isn’t one of them. Every creature that swims close to the surface, be them sharks or whales, will someday die, and when they do, their bodies sink down the water column. Creatures living below the water column feed on these animals, including those that live on the seafloor.
The spot where the geologists drilled for sediments in the Filchner-Ronne ice shelf is about 260 kilometers (160 miles) from the nearest edge of the ice shelf, where the ocean open begins and the nearest source of food ends.
According to Griffiths at the British Antarctic Survey, the only explanation for how these filter feeders survive is that they likely receive nutrients carried in the -2°C water by some yet identified mechanism. Perhaps the food is carried by currents, but the nearest up-current source of sunlight is about 600 kilometers (370 miles) away.
“From looking at the video it appears to be a filter-feeding community, obviously this community must be able to cope with less food than others elsewhere. There are no obvious signs of chemosynthesis, these sponges are not the typical hydrothermal vent or methane seep fauna and the water temperatures are very cold. As far as we know the most likely source of food is what washed in from beyond the ice shelf by the currents, but this requires further investigation,” Griffiths added in an email.
A wild, alternative explanation is that these sponges are, in fact, ancient. Some Antarctic glass sponges are known to be more than 10,000 years old, so perhaps these rock-hugging critters are similar.
Perhaps subsequent expeditions might get to the bottom of it all. Floating ice shelves are considered “the greatest unexplored habitat” in the Southern Ocean, so an investigation is bound to bear interesting findings one way or the other. But scientists will have to perform such investigations fast.
Global warming is closing the window of opportunity for studying unexplored ecosystems in Antarctica. As the region warms past a critical threshold, ice shelves such as Filchner-Ronne Ice Shelf, where this marine life was discovered, are bound to collapse into the sea.
In any event, the big takeaway is that life is even more surprising than we might give it credit for. Even in Antarctica’s harshest environments, there’s still room for life to thrive — and that’s pretty amazing.
“Ice shelves cover roughly a third of the Antarctic’s 5 million km2 continental shelf and the Ronne-Filchner Ice Shelf [where the creatures were found] covers around 420,000 km2, so these environments are surprisingly common but we know virtually nothing about them. Finding filter feeding animals so far from their food source shows us that life beneath ice shelves is more resilient and widespread than we expected.”
“If these communities turn out to be new species, only found under ice shelves then this would make them very vulnerable to climate change and ice shelf collapse, which could destroy their entire habitat in the future,” Griffiths concludes.
A massive iceberg once considered the world’s largest has just lost its leading position by splitting in two and losing a big chunk the size of Queens and the Bronx combined. The A-68a berg first split from Antarctica’s C ice shelf in 2017 and has been drifting to the north ever since
A-68a is essentially a moving frozen island, with cliffs that rise up 30 meters above sea level. It has already drifted about 1,400km north through an area known as “iceberg alley” and is now about 500km away from South Georgia. It’s a track that many icebergs have taken, but the ultimate fate of A-68a is still hard to predict.
The iceberg lost a first chunk soon after splitting from Antarctica and led to the largest section being renamed from A-68 to A-68a and to a smaller piece called A-68B. Then in April 2020 the main iceberg also lost another piece, leading to a new section, A-68C. Now, a crash into the shallow seabed has led to another big split.
Satellite images by the European Space Agency (ESA) showed that the iceberg turned around in a clockwise direction, moving one end of the berg closer to the shelf and into shallow waters. In doing so, the berg could have scraped the seafloor, which caused an enormous block of ice to snap off the iceberg’s northern tip. The chunk of ice now measures 18km long and 140 squared kilometers.
The split means the remaining A-68A iceberg is now much smaller, at about 3,700 square kilometers and with a length of 135 kilometers — and it’s no longer the world’s largest. The leading position in the ranking is held by the A-23A iceberg, which measures almost 4,000 squared kilometers and is currently stuck in the Antarctic Weddell Sea.
It’s now unclear the direction to which the main A-68A iceberg is now heading. Scientists at ESA believe that it could follow its journey to the island of South Georgia as many other previous icebergs have done in the past, moving in a southeast direction, before turning north. The map below shows the different positions of the berg over the past three years.
Sue Cook, a glaciologist at the Australian Antarctic Program Partnership, told The Guardian said that while the iceberg is following a familiar track to many others its ultimate fate is hard to predict. Weather patterns, currents, and the shape of the iceberg made predictions difficult, she added.
Scientists are concerned that if the iceberg remains offshore for too long it could block the nearby waters where the penguins and seals that live on the island feed. More breakage is still possible as the iceberg continues its trajectory.
“The actual distance [the animals] have to travel to find food (fish and krill) really matters,” Geraint Tarling, an ecologist with the British Antarctic Society, said in a statement. “If they have to do a big detour, it means they’re not going to get back to their young in time to prevent them starving to death in the interim.”
More than 30,000 tremors have occurred since the end of August in the Antarctic peninsula, according to a report from the National Seismological Center of Chile. The researchers linked them to the movement of tectonic plates but said the number was unusual and could in fact even be larger.
The tremors were detected in the Bransfield Strait, a 60-mile wide (96-km) ocean channel between the South Shetland Islands and the Antarctic Peninsula. The ranged greatly in intensity (from 0.9 to 5.6), with one earthquake even reaching a magnitude of on November 6th, the researchers said. The earthquake intensity scale is logarithmic — so a magnitude 5 earthquake is 10 times stronger than a magnitude 4 earthquake.
Tectonic plates and microplates meet near the strait and this can normally lead to tremors. But activity in the past three months has been truly unusual. The tremors registered were the most conspicuous or detectable ones, so the Chilean researchers anticipate the number could grow after studying them more.
The tremors were first registered in late August, with a 4.9 magnitude tremor on the 29th and another with a 5.4 magnitude the following day. They peaked in September with an average of 1,000 per day and started to reduce in number and intensity in November, with only 100 localized tremors registered back then.
They were so frequent that the strait, which usually increases in width at a rate of about seven to eight millimeters a year, is now expanding 15 centimeters a year. This suggests that the Shetland Islands are separating faster from the Antarctic peninsula, Sergio Barrientos, one of the researchers, told Reuters
Barrientos and his colleagues related the phenomenon to the characteristics of the tectonic plates near the Antarctic Peninsula. “It’s a complex area since there are various processes of convergence, divergence, and lateral sliding of plate segments in a relatively small area,” they wrote in a statement.
Two studies published earlier this year raised further concern regarding what’s happening in the region. Scientists found the first active leak of methane gas from the Antarctic seafloor, a process likely to accelerate climate change, and also learned that the ice sheet is less stable than previously thought. However, it’s unclear exactly how the earthquakes play into the situation.
Climate scientist Raul Cordero of the University of Santiago told Reuters that it was not yet clear how the larger number of tremors might be affecting the region’s ice, already diminishing because of climate change. “There’s no evidence that this kind of seismic activity has significant effects on the stability of polar ice caps,” Cordero said.
The Arctic saw its lowest average October sea ice extent since satellite measurements began in 1979, according to European Copernicus Climate Change Service. Their monthly report also showed that last month was the warmest on record in Europe, with many areas seeing above-average temperatures in the East, but below average in the southwest.
The Copernicus Climate Change Service (C3S) publishes monthly climate bulletins reporting on the changes observed in global surface air temperature, sea ice cover, and hydrological variables. All the findings are based on computer-generated analyses using billions of measurements from satellites, ships, aircraft, and weather stations.
The average Arctic sea ice extent last month was 5.4 million km2, 1.5 million km2 above September. However, sea ice grew at a slower rate than in 2012, the year with the lowest sea ice extent for September, the report showed. This led to 2020 having the lowest extent recorded in October since observations started.
The map of average sea ice concentrations for October showed ice-free conditions stretching eastward from north of Svalbard to the Chukchi Sea. The largest negative ice concentration anomalies relative to the 1981-2010 average occurred north of the Laptev and East Siberian Seas and were associated with temperature anomalies.
Contrary to the Arctic, the Antarctic saw sea ice reach its annual maximum extent in September and the sea ice melting season has now begun. Sea ice extent reached 18.3 million km2 on average. This is 0.3 million km2 above the 1981-2010 average for October and is the first positive October anomaly observed since 2016.
The report showed above-average ice concentration in most of the Antarctic region. The east of the Antarctic Peninsula, as well as the north and west stretches of the Ross Sea had the largest positive anomalies, while the north Amundsen Sea and parts of the Indian Ocean sector had below-average ice concentration.
Europe sees a record October
Central, eastern, and northern Europe had a warmer October than the 1981-2010 average for the month, Copernicus showed. Temperatures were particularly high in countries near the Black Sea, while European countries southwest the Alps had cooler weather than average.
Many continental land areas and islands north of the Arctic Circle had extremely high temperatures in October. That was also the case of the Arctic Ocean and its bordering coastal seas, especially eastward of Svalbard to the Beaufort Sea. Temperatures were also higher than average around the Mediterranean Sea.
Temperatures over the western USA also continued to be high above average. Paraguay, Bolivia, and southern Brazil saw heatwave conditions, as well as Namibia and other countries in southern Africa. Much of the rest of Africa also had above-average temperatures.
Globally it was the third-warmest October, but only marginally from the fourth, fifth, and sixth warmest Octobers. It was 0.62°C warmer than the 1981-2010 average for the month. The six warmest Octobers occurred within the last six years, the report adds.
It’s almost certain that 2020 will be among the hottest years ever, with a higher than 98% likelihood it will rank in the top five, according to the National Oceanic and Atmospheric Administration, which also releases monthly temperature analyses. Last year (2019) was the second-hottest year ever, and the last year of the hottest decade worldwide.
Global warming is melting the planet’s ice. Greenland is losing ice mass at record rates and parts of Antarctica have entered a phase of instability. But that’s more than just a problem in itself — it can trigger a whole new range of problems, a new study reports.
The dark side of ice melt
It’s easy to forget that climate change isn’t just one phenomenon — it’s a massive chain of interlinked phenomena that affect and influence each other. So when we’re talking about something like polar ice melt, doesn’t end with just that, it triggers a chain of other events.
In a new study, a team of scientists from the Potsdam Institute for Climate Change Research in Germany analyzed how rising temperature and ice melt feed off other.
“If global ice masses shrink, this changes how much of the sunlight that hits Earth’s surface is reflected back into space. Decreasing ice cover in the Arctic exposes more of the darker ocean water that absorbs more energy,” said in a statement Nico Wunderling, lead author of the study.
According to the findings, without changes in the levels of carbon dioxide, massive melting of the cryosphere (global ice) would raise temperatures by 0.43ºC — that’s the global average, in icy regions, it would be substantially higher. Thus, in Greenland and West Antarctica, the thermometer would rise up to 5ºC. Meanwhile, around the equator, it would barely register an extra 0.2ºC.
These differences are due to thermal amplification that causes warming in icy parts of the planet. The higher the temperature, the lower the amount of frozen mass. The process is fed back by the disturbance that heating introduces to other components of the system.
The most notable change would be for the so-called albedo effect — the ability of surfaces to bounce off sunlight. The more light surfaces reflect, the less heat they absorb, and snow and ice are excellent reflectors, returning most of the light and heat they receive back to space. But when ice disappears, the rebound diminishes. This process is especially important in the Arctic.
At first glance, the process is straightforward: ice retreats, it leaves behind darker surfaces, so there’s less light reflected and more heat trapped in the system. But there’s an important subtlety which makes that an oversimplification — when ice retreats, surfaces could still be covered by a layer of snow which wouldn’t change much albedo-wise. So researchers had to model this phenomenon, and only then could they confirm that retreating ice will affect the planet’s albedo significantly.
Other altered factors are the temperature in the atmospheric column, the formation of clouds, and the presence of water vapor. Warmer air can hold more water vapor, and water vapor increases the greenhouse effect, another feedback loop amplified by climate change.
“This is not a short-term risk. Earth’s ice masses are huge, which makes them very important for the system as a whole. But even if some of the changes might take hundreds or thousands of years to manifest, it’s possible we trigger them within just a couple of decades,” said in a statement Ricarda Winkelmann, who leads the research group.
Many researchers argue that in those few decades, the Arctic will become completely ice-free during the summer. If so, in addition to the local and global ecological consequences, the temperature will rise 1.5ºC in the Arctic region and 0.19ºC on a global scale, researchers estimate. This local increase in the Arctic will again reduce the albedo, generate even more melting in the land covered by the ice of Siberia, Canada, or Greenland, which will lower albedo even more, feeding back the warming and starting over. It’s quite a vicious cycle that we could do well without.
From the late 1970s to the mid-2000s, Arctic summer sea ice area has declined by more than 10% per decade. If this trend continues, the Arctic could become ice-free in summer for the first time within the 21st century. At the same time, mountain glaciers world-wide have retreated, losing 21% of their volume between 1901 and 2009.
Moreover, both the West Antarctic and the Greenland Ice Sheet have lost mass at an accelerating pace in the past decades. As global warming progresses, ice loss from the polar ice sheets and subsequent sea-level rise is expected to further increase. Beyond a temperature threshold, large parts of the Greenland Ice Sheet might melt.
The Dome A, the highest ice dome on the Antarctic Plateau, is the best place on the planet to study the stars, providing the clearest views of the sky at night, according to new research, which will probably trigger the interest of astronomers ready to cope with the Antarctic cold weather.
Ice domes are the uppermost portions of ice sheets and rise high above the frozen terrain. The Dome A is considered one of the coldest places on Earth, with temperatures that can be as low as -90ºC (-130 Fahrenheit). That’s actually similar to the nighttime weather found on Mars.
That means that while it may be a great place for astronomers, its remote location and extreme conditions present significant challenges. Scientists that want to visit the Dome A would have to travel 1,200 kilometers (740 miles) into the interior of the Antarctic continent — and that’s after traveling to Antarctica itself.
“The combination of high altitude, low temperature, long periods of continuous darkness, and an exceptionally stable atmosphere, makes Dome A a very attractive location for optical and infrared astronomy. A telescope located there would have sharper images and could detect fainter objects,” said Paul Hickson, co-author of the study, in a press release.
For astronomers, light pollution isn’t just the only problem when looking at the night sky. Atmospheric turbulence can also affect clear views into space. That’s when the telescopes located at mid and high elevations become very useful, taking advantage of the weaker turbulence found at those locations.
Astronomers calculate the quality of the night sky view using a metric called the seeing number, which they measure in arcseconds. The lower the number, the lower the turbulence and the better the view they can get from the stars and the galaxies. In the elevated telescopes in Chile and Hawaii, the seeing number is 0.6 to 0.8 arcseconds.
At Dome C, which is another dome on the Antarctic Plateau, the number is between 0.23 and 0.36 arcseconds. This means that the continent is an ideal place to watch the night sky. The level of turbulence there is lower as the boundary layer, the lowest part of the Earth’s atmosphere.
Working with researchers from China, Canada, and Australia, Hickson showed in his study that the Dome A is actually better than the Dome C. They took nighttime measurements at that location, something that hadn’t been done before, and found out that the median seeing number was 0.31 arcseconds.
The researchers compared the two Antarctic sites and found that the measurements from Dome A at eight meters (26 feet) were much better than the ones taken at the same height at Dome C. The measurements from Dome A at this height were equivalent to the ones made at 20 meters (66 feet) at Dome C.
Dome A “is a natural laboratory for studies of the formation and dissipation of turbulence within the boundary layer,” wrote the authors in their paper. “Future measurements of weather, seeing and the low-altitude turbulence profile could contribute to a better understanding of the Antarctic atmosphere.”
Climate change is bringing more bad news to Antarctica — according to not one, but two recent studies published this week.
In one study, scientists found the first active leak of methane gas from the Antarctic seafloor. In the second, they learned that the ice sheet is less stable than previously thought.
This is not good news
Antarctica is witnessing some of the most rapid warming on Earth. In the last 50 years, it has warmed almost 3ºC (5.4 Fahrenheit), much higher than the global average of 0.9ºC (1.6 Fahrenheit). This has led to visible effects, including snow turning red, reduced penguin populations, and ice retreat. But the changes aren’t always obvious, and sometimes it takes a while to see all of them.
A group of researchers has discovered for the first time an active leak of methane gas from the seafloor, a process likely to accelerate climate change. Methane is a powerful greenhouse gas, more potent than CO2; the risk of it leaking from under ice has long worried scientists.
The study said the leak was first discovered in 2011, and for several years, it’s been leaking right beneath the surface. According to researchers, methane-consuming microorganisms are now present at the seep and limit some of its emissions, but it took five years for the microorganisms to develop at the site. Andrew Thurber, an oceanographer who led the research, told The Guardian that this “is not good news” and that the microbes were of an unexpected strain.
To make things even worse, a second seep was discovered in 2016. A large amount of methane is stored under ice, with Antarctica estimated to have as much as a quarter of Earth’s marine methane. Researchers have longed warned the climate effect a methane leak would bring to an already warming planet. In 2018, NASA said ice melting in the Arctic could release methane to the atmosphere.
The release of methane from ice is also considered one of the tipping points in climate change, where the effects of rising temperatures cannot be stopped or reversed. But until now no active leak of methane had been registered in Antarctica. The findings will now help to understand how methane is consumed and released in Antarctica, but researchers fear we may be already losing control of the Earth’s climate.
Antarctica’s ice sheet is shaking
A group of researchers at the University of California, Santa Cruz, University of Washington, and the University of Kansas, report that the East Antarctic ice sheet isn’t as stable as previously thought, adding to the many pieces of evidence of historic ice loss in the area.
The study found evidence that East Antarctica experienced melting 400,000 years ago when the world was 1ºC to 2ºC (1.8 to 3.6 Fahrenheit) warmer. Enough ice melted could have happened there to raise the sea by about 10 to 13 feet (3 to 4 meters), the researchers argued.
Back in 2017, a previous study discovered evidence based on sediment data, suggesting the glaciers in the region experience cycles of advance and retreat. This challenged the previous idea that this part of Antarctica had remained frozen for millions of years. Then, in 2019, researchers found the regions were already experiencing some ice loss, which raised concerns.
This paper elevates those concerns even more. The researchers looked at three samples of subglacial sediment to see what minerals have accumulated beneath the ice historically. The team focused on the Wilkes Basin, a huge swath of ice that covers an area roughly the size of France.
They were able to date the opal and calcite found in their samples, taken near the Pensacola Mountains and Elephant Moraine in East Antarctica. The samples showed that East Antarctica hasn’t been stable for as long as previously thought. About 400,00 years ago the ice receded in the basin, contributing to sea-level rise. While researchers have grown worried over parts of the West Antarctic ice sheet facing a likely collapse, the new findings show some of the eastern portions of the continent could be in trouble.
“This supports the idea that future sea levels in response to warming will be much higher than present,” Terry Blackburn, one of the authors, said in a statement.
We’ve read a lot of bad news from Antarctica lately, and this one-two punch is nothing to scoff at. We may be reaching a climate tipping point — after which there could be no turning back.
Antarctica is by the most pristine and least polluted continent on the planet. It has no towns, agriculture, or industry. But that doesn’t mean it’s unaffected by human activity.
According to a new study, mankind has left a big footprint over the years, in Antarctica, going far beyond the scientific stations and ecotourism.
Explorers and scientists first arrived on the shores of the continent more than 200 years ago. Since then, expeditions have crisscrossed the many kilometers of Antarctica’s ice sheet multiple times, leaving behind widespread impacts.
A study mapped that footprint for the first time, showing it’s much extensive than previously thought.
“We have been nearly everywhere,” Steven Chown, a professor at Monash University in Melbourne and senior author of the study in Nature, told AFP. “But these visits are often brief or to places covered in ice. The impacts in these areas are very small, negligible.”
The study looked at about 2.7 million records of human activity, spanning over 200 years and used it to quantify the extent of Antarctica’s wilderness and its representation of biodiversity. Up to 99.6% of the continent can still be considered wilderness, but only has a few biodiversity features, the researchers found.
This doesn’t mean that no damage has been done. The areas that have the least human impact don’t include some of the most important biodiversity of Antarctica, Chown explained. As it turns out, high human impact areas, including research facilities and tourism, usually overlap with areas important for biodiversity.
For example, of the continent’s bird areas that are critical for conservation efforts, only 16% are inside zones that the researchers identified at “negligibly impacted areas” — the rest have been affected. Meanwhile, land-based life can mostly be found in a few ice-free areas that comprise less than half of the continent’s surface, or approximately 45,000 square kilometers.
“Biodiversity is the basis for all life. It inspires us to be better people and to have greater appreciation of our place in the world—just think of albatrosses,” said Chown. “Antarctic biodiversity helps us understand what life may be like elsewhere in the Universe. Microbes can live by scavenging hydrogen gas from the air—remarkable!”
Pristine areas, free from human interference, cover less than 32% of Antarctica, and the figure is declining as human activity escalates, the study found. That’s why researchers called for an urgent expansion of Antarctica’s network of specially protected areas, which can reverse this trend and secure the continent’s biodiversity
Specially protected areas currently cover less than 2% of Antarctica but include 44% of identified species, including seabirds, plants, lichens, and invertebrates. Most of these areas were established in 1961 under the Antarctic Treaty System, which governs the continent and protects against human development. Given the scale of human impact, it’s high time for a revision of that list.
When you hear the word desert, the mind usually drifts towards sun, sand, and dunes. But in truth, deserts are much more varied than you’d imagine. They come in all shapes and sizes and vary quite a lot from one part of the world to the next one.
You’ll probably be surprised to learn that the largest desert in the world is actually the Antarctic.
Deserts are far more than the desolate landscapes we often picture them as. They are biologically rich habitats with a wide array of animals and plants that have adapted to living there. Some deserts are among the last remaining areas of true wilderness on the planet, yet many people call them home: more than one billion people (a sixth of the global population) actually live in desert regions.
Deserts cover more than one-fifth of the Earth’s land area and can be found on every continent — and only 20% of them are covered in sand.
So what makes a desert?
A place that receives less than 25 centimeters (or 10 inches) of rain per year is considered a desert. They are part of a wider type of region called drylands, which are defined by a scarcity of water. Drylands can lose more moisture through evaporation than they obtain from precipitation.
Despite the usual misconceptions, deserts can be both hot and cold. The Sahara is the largest hot desert in the world and can reach temperatures of up to 122 degrees Fahrenheit (50 degrees Celsius) during the day.
But deserts can also be cold, such as the ones in the Antarctic and the Arctic — which also happen to be the largest two deserts overall. Cold deserts don’t necessarily need to be freezing: the Gobi desert in Asia is considered to be a cold desert since it is sometimes covered by snow and frost. However, winds can cause dramatic temperature shifts in the Gobi desert, shifting from −40 °C (−40 °F) in winter to 45 °C (113 °F) in summer. These rapid temperature shifts occur not only seasonally, but can even take place in the same day.
The world’s driest deserts like the Atacama Desert in Chile have areas that get less than .08 inches (or two millimeters) of precipitation a year. They are such harsh environments that researchers have studied them to get a better idea about life on Mars. But every few years they a very rainy period called “super blooms.” The Atacama Desert may be the oldest desert on earth, being hyper-dry for over 3 million years.
The largest desert in the world
Purely in terms of size, the Antarctic Desert is the largest desert on the planet, measuring a total of 13.8 million square kilometers (or 5,500,000 square miles). Antarctica is not only the most isolated continent on Earth but also the coldest. It’s considered a desert as its annual precipitation is less than 51 millimeters (or two inches).
To put that into perspective, much of the Sahara Desert gets twice as much rain as the Antarctic. The coastal regions of Antarctica receive more rain, but still average only 200 millimeters (or eight inches) per year. Unlike most desert regions, however, the rain doesn’t soak into the ground. Instead, the snow piles on top of itself.
Despite having so little rain, Antarctica still gets massive windstorms. Just like the sandstorms seen in hot deserts, the high winds pick up snow and turn into blizzards. The storms can reach speeds of up to 320 km an hour (200 mph) and are one of the reasons the continent is actually so cold.
The continent is covered by a permanent ice sheet that contains 90% of the Earth’s freshwater and averages 1.6 kilometers in thickness. Only 2% of Antarctica isn’t covered by ice, an area mainly located along the coasts where penguins, whales, birds, seals and other animals reside.
There aren’t permanent human residents in Antarctica, but between 1,000 and 5,000 researchers can be found at different times of the year in the research stations across the continent. The largest one is McMurdo Station, located on the tip of Ross Island and managed by the United States.
The Antarctic can also get freakishly cold. The coldest temperature ever recorded was taken at the Soviet Vostok Station on the Antarctic Plateau. It reached a historic low of -89.2°C (-129°F) on July 21st, 1983, and was obtained using ground-based measurements. Satellite data indicated a temperature of around -93.2 °C on August 10th, 2010 but the reading hasn’t been confirmed.
Other large deserts in the world
Curiously, the second-largest desert in the world is also cold. The Arctic Desert covers a total area of about 13,7 million square kilometers (5,29 million square miles). The total amount of precipitation is below 250mm (10 inches), which is predominantly in the form of snow.
The desert partially occupies parts of territories claimed or controlled by Canada, Denmark, Norway, Russia, Sweden, and the United States. The average temperature in the Arctic Desert is -20 °C, reaching as low as -50 °C in the winter. During summer, the sun doesn’t set for 60 days. Then, in winter, there are extended periods of darkness.
The third-largest desert in the world is the well-known Sahara, which is also the world’s largest hot desert. It has a total size of 9,4 million square kilometers (or 3,3 million square miles). It occupies most of the land in North Africa except for the regions of the Maghreb, the Atlas Mountains, and the coastal region next to the Mediterranean Sea.
The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and eastern parts. Most of the Sahara receives less than 20 millimeters (or 0.79 inches). Temperatures are also quite intense in the Sahara, and can rise to more than 50 °C.
Located in Western Asia, the Arabian desert is the fourth largest one on Earth. It covers an area of 2,3 million square kilometers (or 900,000 square miles). It encompasses much of Yemen, the Persian Gulf, Oman, Jordan, and Iraq. Its center, known as the empty quarters, forms the largest continuous body of sand in the world.
The climate of this area is very dry. Temperatures oscillate between regular, characteristically high heat on one end of the spectrum to seasonal nighttime freezes on the other. The annual rainfall is around 100mm on average, but the driest areas receive as little as 30 to 40 mm of rain a year.
Also in Asia, the Gobi Desert is known as the fifth-largest desert in the World. It has a total land area of 1.2 million square kilometers (or 500,000 square miles) and covers parts of northwestern and northern China, as well as southern Mongolia. It’s called the “rain shadow desert” as the Himalayan Mountains block the rainfall from the desert. It’s not a sandy desert and instead has exposed, bare rock.
Desertification and environmental challenges
A significant number of the world’s semi-arid regions are turning into deserts at record speed through a process known as desertification. This isn’t caused by natural drought but rather by deforestation and demands from human populations that establish in the semi-arid lands.
For example, in northern China, the expansion of urbanization, which left the land unprotected against wind erosion, and the accumulation of sediment from a surrounding desert recently created a desertification problem. Replying to it, the government built a so-called great green wall to act as a border against the desert.
But that’s not the only challenge that deserts are dealing with. Species in existing deserts are threatened by a warmer world. Higher temperatures cause more wildfires that then change the desert landscapes, eliminating slow-growing trees and shrubs and replacing them with fast-growing grasses.
Scientists have warned that the iconic Joshua tree from California might not survive a hotter climate. If that’s actually the case, the effect would also be severe in other species such as the yucca moth, which deposits its eggs into the flower of the Joshua tree — and the effects could cascade down the food chain. Many desert birds could also be affected by dehydration and might not be able to survive in hotter deserts.
Deserts are a natural part of our ecosystem, but as it is so often the case, human intervention is changing the natural cycles. This change is often much quicker than natural change, which renders ecosystems incapable to adapt in time.+
Climate scientists long thought Antarctica’s interior may not be very sensitive to warming, but our research, published today, shows a dramatic change.
Over the past 30 years, the South Pole has been one of the fastest changing places on Earth, warming more than three times more rapidly than the rest of the world.
My colleagues and I argue these warming trends are unlikely the result of natural climate variability alone. The effects of human-made climate change appear to have worked in tandem with the significant influence natural variability in the tropics has on Antarctica’s climate. Together they make the South Pole warming one of the strongest warming trends on Earth.
The South Pole is not immune to warming
The South Pole lies within the coldest region on Earth: the Antarctic plateau. Average temperatures here range from -60℃ during winter to just -20℃ during summer.
Antarctica’s climate generally has a huge range in temperature over the course of a year, with strong regional contrasts. Most of West Antarctica and the Antarctic Peninsula were warming during the late 20th century. But the South Pole — in the remote and high-altitude continental interior — cooled until the 1980s.
Scientists have been tracking temperature at the Amundsen-Scott South Pole Station, Earth’s southernmost weather observatory, since 1957. It is one of the longest-running complete temperature records on the Antarctic continent.
Our analysis of weather station data from the South Pole shows it has warmed by 1.8℃ between 1989 and 2018, changing more rapidly since the start of the 2000s. Over the same period, the warming in West Antarctica suddenly stopped and the Antarctic Peninsula began cooling.
One of the reasons for the South Pole warming was stronger low-pressure systems and stormier weather east of the Antarctic Peninsula in the Weddell Sea. With clockwise flow around the low-pressure systems, this has been transporting warm, moist air onto the Antarctic plateau.
South Pole warming linked to the tropics
Our study also shows the ocean in the western tropical Pacific started warming rapidly at the same time as the South Pole. We found nearly 20% of the year-to-year temperature variations at the South Pole were linked to ocean temperatures in the tropical Pacific, and several of the warmest years at the South Pole in the past two decades happened when the western tropical Pacific ocean was also unusually warm.
To investigate this possible mechanism, we performed a climate model experiment and found this ocean warming produces an atmospheric wave pattern that extends across the South Pacific to Antarctica. This results in a stronger low-pressure system in the Weddell Sea.
We know from earlier studies that strong regional variations in temperature trends are partly due to Antarctica’s shape.
The East Antarctic Ice Sheet, bordered by the South Atlantic and Indian oceans, extends further north than the West Antarctic Ice Sheet, in the South Pacific. This causes two distinctly different weather patterns with different climate impacts.
More steady, westerly winds around East Antarctica keep the local climate relatively stable, while frequent intense storms in the high-latitude South Pacific transport warm, moist air to parts of West Antarctica.
Scientists have suggested these two different weather patterns, and the mechanisms driving their variability, are the likely reason for strong regional variability in Antarctica’s temperature trends.
What this means for the South Pole
Our analysis reveals extreme variations in South Pole temperatures can be explained in part by natural tropical variability.
To estimate the influence of human-induced climate change, we analysed more than 200 climate model simulations with observed greenhouse gas concentrations over the period between 1989 and 2018. These climate models show recent increases in greenhouse gases have possibly contributed around 1℃ of the total 1.8℃ of warming at the South Pole.
We also used the models to compare the recent warming rate to all possible 30-year South Pole temperature trends that would occur naturally without human influence. The observed warming exceeds 99.9% of all possible trends without human influence – and this means the recent warming is extremely unlikely under natural conditions, albeit not impossible. It appears the effects from tropical variability have worked together with increasing greenhouse gases, and the end result is one of the strongest warming trends on the planet.
These climate model simulations reveal the remarkable nature of South Pole temperature variations. The observed South Pole temperature, with measurements dating back to 1957, shows 30-year temperature swings ranging from more than 1℃ of cooling during the 20th century to more than 1.8℃ of warming in the past 30 years.
This means multi-decadal temperature swings are three times stronger than the estimated warming from human-caused climate change of around 1℃.
The temperature variability at the South Pole is so extreme it currently masks human-caused effects. The Antarctic interior is one of the few places left on Earth where human-caused warming cannot be precisely determined, which means it is a challenge to say whether, or for how long, the warming will continue.
But our study reveals extreme and abrupt climate shifts are part of the climate of Antarctica’s interior. These will likely continue into the future, working to either hide human-induced warming or intensify it when natural warming processes and the human greenhouse effect work in tandem.
The cleanest air in the world is located above the Southern Ocean, near Antarctica, according to a study that measured the composition of the air in the area. The researchers described it as “truly pristine” and unaffected by pollution from human activities.
Led by Dr. Sonia Kreidenweis, a group of climate scientists from Colorado University was curious to see just how far particles produced by human activity could travel. To find out, they sailed into the Southern Ocean and measured the composition of the air at several points.
They took measurements from the boundary layer, a part of the lower atmosphere that comes in direct contact with the surface of the ocean and reaches as an altitude as high as 1.2 miles (1.9km). The samples showed no particles that were connected to human pollution or other activities.
Instead, the researchers were able to trace most of the particles and the bacteria researches back to upwind territories and other nearby areas where bacteria and microscopic matter from the ocean mixed with the wind and circulated through the atmosphere.
“We were able to use the bacteria in the air over the Southern Ocean as a diagnostic tool to infer key properties of the lower atmosphere,” Colorado State’s Thomas Hill, co-author, told the university’s news blog. “This is one of the very few places on Earth that has been minimally affected by anthropogenic activities.”
The findings surprised the researchers as they go against other studies from oceans in the northern hemisphere and subtropics, which have found most microbes drift in from upwind continents. “Antarctica appears to be isolated from southward dispersal of microorganisms and nutrient deposition from southern continents,” said Hill.
One possible reason for this is that the aerosols feeding clouds over the Southern Ocean are different than elsewhere on Earth, due to their isolation from aerosols released from large landmasses. This information is not used in most climate models, with only a few studies of clouds and aerosols so far conducted in the region.
This means that, besides acknowledging this part of the Southern Ocean as a rare bastion of truly unpolluted air, the research is also important for climate and weather modeling. The aerosol composition of the boundary layer affects cloud composition and precipitation, which then affects the amount of sunlight reaching the Earth’s surface.
“These results provide observational support for the suggestion that this region of the Southern Ocean represents one of very few marine boundary layer regions across the globe that is unlikely to have changed due to anthropogenic activities,” the researchers wrote.
In 2019, researchers had identified Cape Grim in Tasmania, near the northern edge of the Southern Ocean, as the previous site with the cleanest air in the world. The area is advertised by local cattle farmers for the quality of the beef – thanks to the quality of the air and the clear rainwater, they argue.
The Antarctic peninsula is one of the fastest-warming regions on the planet. Temperatures have already increased 1.5ºC compared to pre-industrial levels and this is likely to continue, leading to a wide set of consequences.
Among them, and one of the most visible ones has been the so-called green-snow. Blooming algae across the surface of the peninsula are causing the snow to turn green. The phenomenon can be linked to climate change and is likely to spread further across the icy continent as temperatures go up, according to a new study.
A group of researchers created the first large-scale map of microscopic algae on the Antarctic peninsula, using on-the-ground measurements and satellite data gathered between 2017 and 2019. Warmer temperatures create more “habitable” conditions for the algae, the authors argued.
“With the available area for plant colonization on the Peninsula likely to increase by up to threefold due to this warming, understanding how snow algae fit into Antarctica’s biosphere and their probable response to warming is critical to understanding the overall impact of climate change on Antarctica’s vegetation,” the study reads.
The map will be used as a baseline to understand the speed at which the Antarctic Peninsula is turning green due to the climate crisis, offering sustenance to other species. The researchers already found the algae can form bonds with fungal spores and bacteria. “It’s the start of new ecosystems,” Matt Davey, one of the authors, told The Guardian.
Large areas of green snow can now be seen along the coastline of the Antarctic Peninsula, mostly in warmer areas that have temperatures above zero degrees Celsius in the summer months – which go from November to February. Unusually high temperatures were recorded in February, including a few heat-waves.
The researchers identified 1,679 separate blooms of green algae on the snow surface, covering an area of 1.9 km2. This represents a carbon sink of around 479 tons per year. A carbon sink is a reservoir that absorbs more carbon than it releases. Almost two-thirds of the algal blooms were found on small islands around the peninsula.
“As Antarctica warms, we predict the overall mass of snow algae will increase, as the spread to higher ground will significantly outweigh the loss of small island patches of algae,” Dr Andrew Gray, lead author of the paper, and a researcher at the University of Cambridge, said in a statement.
The researchers had noticed in the past changes in green lichen and moss in the Antarctic Peninsula. But these grow extremely slowly compared with algae.
In the future, the team will focus on measuring red and orange algae in order to determine how their presence might be affecting the heat-reflecting albedo quality of the snow.
The icy continent of Antarctica wasn’t always the barren landscape that we all know today. As early as 90 million years ago, the continent may have been covered in a temperate rainforest, similar to what you’d find in today’s New Zealand, instead of an ice cap.
The study was carried out by an international team of experts who analyzed preserved roots, pollen, and spores found in cores of sediment drilled within 900 kilometers of the South Pole.
The fossilized soil is estimated to be 90 million years old, placing it in the mid-Cretaceous, a geological period during which the dinosaurs were at their heyday.
This was also the warmest period in the past 140 million years, with temperatures easily reaching 35 degrees Celsius in the tropics. Sea levels were also a staggering 170 meters (560 feet) higher than today.
However, not much is known about what the environment looked like in the South Pole during that period.
Researchers knew they were on to something when they noticed a strange color in a section of a sediment core drilled into the seabed near the Pine Island and Thwaites glaciers in West Antarctica.
“During the initial shipboard assessments, the unusual colouration of the sediment layer quickly caught our attention; it clearly differed from the layers above it,” said first author Dr Johann Klages, a geologist at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany.
Upon analyzing this section with computer tomography techniques, the scientists came across a dense network of fossil roots. The samples were pristinely preserved, allowing the researchers to make out individual cell structures. There were even remnants of flowering plants — the earliest ever found at such high Antarctic latitudes.
In order to establish the climatic conditions of the time, the team compared the environments in which the fossilized plants’ modern descendants live. They also took into account temperature and precipitation indicators within the sample.
“It was particular fascinating to see the well-preserved diverse fossil pollen and other plant remains in a sediment deposited some 90 million years ago, near the South Pole,” said Professor Ulrich Salzmann, a palaeoecologist at Northumbria University and co-author of the new study.
“The numerous plant remains indicate that the coast of West Antarctica was, back then, a dense temperate, swampy forest, similar to the forests found in New Zealand today,” he added.
The analysis suggests that the annual mean air temperature in the South Pole at the time was around 12 degrees Celsius. For comparison, that’s two degrees warmer than the mean temperature in Germany today.
Summer was much warmer, with temperatures hovering at around 19 degrees Celsius, while rivers and swamps were likely around 20 degrees in temperature. Regarding precipitation, Antarctica was probably as rainy as today’s Wales.
Considering these climatic conditions, Antarctica was completely ice-free. This was despite a four-month polar night, meaning for a third of every year there was no life-giving sunlight at all.
“The preservation of this 90-million-year-old forest is exceptional, but even more surprising is the world it reveals. Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected,” said Professor Tina van de Flierdt, from the Department of Earth Science & Engineering at Imperial College London.
Antarctica’s surprisingly warm and tropical past suggests that carbon dioxide levels in the atmosphere were much higher than expected during the mid-Cretaceous period, which lasted from 115 to 80 million years ago. According to the researchers, CO2 levels may have been as high as 1680 parts per million (ppm), roughly four times higher than they are today.
“Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm. But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”
The findings were published in the journal Nature.
Among the many consequences of climate change, extreme weather events are usually on top of the list. Heatwaves, flooding, and droughts, among many others, are already becoming more frequent and impactful across the globe, and Antarctica is no exception.
Researchers at the Australian Antarctic Program reported the first recorded heatwave event at the Casey research station in East Antarctica. The event, which took place during the 2019-2020 summer, is likely to have impacted biological systems across the continent and accelerated ice melt.
Heatwaves happen when three consecutive days with both extreme and minimum temperatures are reported. Between January 23rd and 26th, the research station recorded minimum temperatures above zero and maximum above 7.5º (45.5 ºF), with the highest m9.2º C (48.5 ºF), being recorded on the 24th. The highest minimum, 2.5º C (36.5 ºF) was recorded the following morning.
The maximum is 6.9º C (44.4 ºF) higher than average for the station, while the minimum is 0.2º C (32.3 ºF) above average.
Land-based meteorological stations in Antarctica have measured temperatures as low as −89.2 °C (−128.6 °F) in the past. Satellites identified even lower temperatures, of -93.2 °C (−135.8 °F). Australian Antarctic Division applied Antarctic ecologist, Dr. Dana Bergstrom, and a group of researchers said that in the past a large part of East Antarctica had been spared from climate warming due to ozone depletion, which cools surface temperature and creates strong winds.
But these record-breaking temperatures seem long gone. The warmer temperatures reported on by the station can be linked to higher than average temperatures across different parts of Antarctica and to other meteorological patterns during the spring and summer of 2019 in the Southern Hemisphere, all influenced by the early breakup of the ozone hole in 2019.
“The upper levels of the atmosphere at the edge of Antarctica were strongly disturbed in the spring of 2019, and effects of this likely further influenced the lower atmosphere over Antarctica during the summer,” Dr Andrew Klekociuk said in a statement, adding there are now international controls working to close the ozone hole.
The researchers believe that the warm summer reported in Antarctica will likely lead to long-term disruption to local populations, communities, and the broader ecosystem. This disruption could be both positive and negative.
“Most life exists in small ice-free oases in Antarctica, and largely depends on melting snow and ice for their water supply,” Dr Bergstrom said in a statement. “Meltwater flooding can provide additional water to these desert ecosystems, leading to increased growth and reproduction of mosses, lichens, microbes, and invertebrates.”
Nevertheless, according to Bergstrom, excessive flooding can displace plants and alter the composition of invertebrates and microbial mats. “If the ice melts completely, early in the season, then ecosystems will suffer drought for the rest of the season,” she added.
Global warming is kicking in across the globe and Greenland and Antarctica are among the worst affected regions.
Both are losing ice six times quicker than in the 1990s, and if that continues sea level rise will increase an extra 17 centimeters by 2100 — in line with the worst-case scenario set by UN experts.
Those are the main conclusion of an analysis by experts from 50 international organizations, who have used data from 26 studies to calculate changes in the mass of the ice sheets in Greenland and Antarctica between 1992 and 2018.
The results were published in two articles in the online version of the journal Nature in 2018 (Antarctica) and 2019 (Greenland). The researchers now reported the combined data from the two areas in a press release distributed by the University of Leeds, UK.
The figures show that Greenland and Antarctica lost 6.4 trillion tons of ice between 1992 and 2017, which raised the level of the world’s seas by 17.8 millimeters. Of the total sea-level rise, 10.6 millimeters (60%) were due to Greenland ice losses and 7.2 millimeters (40%) to Antarctic losses.
The combined rate of ice loss has increased six-fold in just three decades, from 81 billion tons per year in the 1990s to 475 billion tons per year in the 2010s. This means, according to the authors, that the polar ice sheets are now responsible for a third of all sea-level rise.
“If Antarctica and Greenland continue to alienate themselves with the worst-case scenario of global warming, they will cause an additional 17 centimeters to rise in sea level at the end of the century,” said in a statement Andrew Shepherd of the University of Leeds, adding that 400 million people would be at risk.
The loss of the ice sheets coincided with several years of intense melting of the Greenland surface, according to these authors, which said that the heatwave in the Arctic last summer should set a new record. Antarctica and Greenland are losing ice five and seven times faster than in the 1990s, respectively.
In its fifth assessment report, the United Nations Intergovernmental Panel on Climate Change (IPCC) predicted that the global sea level would rise by 53 centimeters by 2100 and it is estimated that this would put 360 million people at risk of coastal flooding.
“We cannot know whether it is too late to stop climate change. Urgent and drastic measures are needed to decrease the contribution of CO2 and other polluting gases to the atmosphere, and still, we don’t know if it will be enough,” said Gorka Moyano, one of the researchers involved in the studies.
Are my eyes playing tricks or did the snow in Antarctica turned red? That’s what many people recently asked after seeing viral photos from a Ukrainian based, fully covered by red or watermelon snow.
But there’s a logical explanation behind the phenomenon. The color is due to the flowering of thousands of unicellular algae called Chlamydomonas nivalis, which contain red carotene (astaxanthin) to protect against ultraviolet radiation.
The substance “acts as a sunscreen, protecting the algae from the dreaded ultraviolet radiation, but allowing the passage of other wavelengths necessary to perform photosynthesis,” said the Spanish physicist Mar Gomez on a Twitter thread.
The viral photos were captured by marine ecologist Andrey Zotov from the National Academy of Sciences of Ukraine while he was doing research in the area. He and his colleagues identified the green algae, common in icy and snow regions, with a microscope.
Zotov explained that the green algae sleep during the winter and then wakes up later in the year thanks to the higher temperatures and the sunlight. The algae use the sunlight and the meltwater to bloom, which is the phenomenon seen in the photos.
But this is not exclusive to the green algae, as there are more than 350 different types that can survive extreme temperatures.
The green algae have a two tail-like structure that allows them to swim. When they mature, they lose that mobility but develop features to survive the extreme temperatures, including an insulating cell wall and a layer of red carotenoids, changing their appearance from green to orange to finally red.
At the same time, the carotenoids help the algae to absorb warmth, creating more meltwater for them to thrive. While this is helpful for the algae, it’s not so much for the planet, as the algae bloom has been found to contribute to climate change.
In 2016, a study concluded the snow algal blooms decreases the amount of light reflected from the snow by 13% in one melt season in the Arctic. At the same time, in 2017, researchers argued microbial communities, including the algae, contributed to more than a sixth of the snowmelt in the locations they were present.
Temperature records continue to be broken in Antarctica, one of the regions in the world most affected by climate change, causing the rapid melting of snow and ice. Since the 1950s, the temperature in Antarctica has risen by more than 0.05 °C (0.09 °F) per decade.
Between 1979 and 2017, Antarctica has experienced a sixfold increase in yearly ice mass loss — and this rate doesn’t seem to be slowing down. During this period, global sea levels rose by almost 13 millimeters (half an inch), according to a recent study.
Following the recent record high temperatures, NASA released before-and-after satellite images of the northern Antarctic Peninsula – and the lack of snow is breathtaking.
Most of the shocking photos photos were of Eagle Island, located in the northern part of the Antarctic Peninsula. They were taken by satellites nine days apart, on February 4 and February 13. Although little more than a week had passed, the change was visible..
Just two days after the first photo, Eagle Island reached a record of 18.3 degrees Celsius (64.9 Fahrenheit). It was t-shirt weather — the same temperature registered in Los Angeles on that day, according to NASA.
That led to big losses of ice and snow, losing an inch on February 6 and four inches on February 11.
“The warm spell caused widespread melting on nearby glaciers,” the space agency said on a press release. “Such persistent warmth was not typical in Antarctica until the 21st century, but it has become more common in recent years.”
The record temperature in Antarctica was registered at the Esperanza Base, a continuously manned research station managed by Argentina.
It’s no coincidence that Antarctica is experiencing such high temperatures; after all, it is one of the places most affected by climate change.
Between 1979 and 2017, Antarctica has experienced a sixfold increase in yearly ice mass loss — and this rate doesn’t seem to be slowing down. During this period, global sea levels rose by almost 13 millimeters (half an inch), according to a recent study.
Mauri Pelto, a glaciologist at Nichols College, explained in a statement that high temperatures have now become frequent in the area — although this was not the usual weather pattern researchers are used to. In fact, the Antarctic was generally resilient in the face of melting events elsewhere on the globe. “You see these kinds of melt events in Alaska and Greenland, but not here,” he said.
NASA explained that behind the high temperatures were the result of strong winds that traveled to the mountains, where it cooled and condensed into ice or rain. Then, the heat that was released because of the condensation went down to the other side of the mountain.
“Typically, the peninsula is shielded from warm air masses by the Southern Hemisphere westerlies, a band of strong winds that circle the continent,” NASA said. “However, the westerlies were in a weakened state, which allowed the extra-tropical warm air to cross the Southern Ocean and reach the ice sheet.
Alexandra Isern, the head of Antarctic sciences at the National Science Foundation, told NPR the challenge now will be to establish how much of a role climate change played in these record temperatures. “This was a weather event”, she said, adding researchers are now working on figuring out whether the warm weather event in Antarctica’s northern peninsula is also becoming a climate event.
Scientists had been waiting and watching it for months and it finally happened. A 300 square kilometers (116 square miles) iceberg broke off Pine Island Glacier (PIG), Antarctica’s biggest glacier and also the fastest melting one of the continent.
Thanks to the images of the European Space Agency’s (ESA) Sentinel satellites, last year two large cracks were detected in the glacier in 2019 and scientists have been closely monitoring the speed with which these cracks grow.
The cracks in the glacier expanded fast and eventually led to the splitting of the iceberg on February 9. It took just a day for the iceberg to divide into smaller pieces and one of them was large enough to be named, B-49, and tracked by the United States National Ice Centre.
An animation published by ESA used 57 radar images captured between February 2019 and February 2020 (the last one on February 10) and shows how fast the emerging cracks grew and led to this event.
“What is unsettling is that the daily data stream [from satellites] reveals the dramatic pace at which climate is redefining the face of Antarctica,” said Mark Drinkwater, senior scientist and cryosphere specialist at the European Space Agency, in a press release.
The Pine Island Glacier, together with its neighboring Thwaites Glacier, connects the center of the western Antarctic ice sheet with the ocean, discharging significant amounts of ice to the sea. These two glaciers have been losing ice for the past 25 years.
Due to its extremely remote location, satellites play a fundamental role in the measurement and monitoring of Antarctic glaciology, revealing the timing and pace of the withdrawal of glaciers in Antarctica. Since the early 1990s, the ice speed of the Pine Island glacier has increased dramatically to values exceeding 10 meters per day.
The floating ice front of Pine Island Glacier, which has an average thickness of approximately 500 meters, has undergone a series of detachment events in the past 30 years, some of which have abruptly changed the shape and position of the ice front.
“This indicates that Pine Island ice shelf is weakening as a result of warm ocean water and this is important as the ice in the Amundsen Sea Embayment, where PIG is located, is the area where we scientists are most worried about contributions to sea-level rise,” Stef Lhermitte, a remote sensing scientist from the Delft University of Technology in the Netherlands, said to ABC.
Western Antarctica is one of the regions of the world most affected by climate change and its collapse would mean a significant sea-level rise. A recent study showed that global warming changed the character of the winds that blow over the ocean near some of the glaciers, affecting them in severe ways.
The new development on the Pine Island Glacier happened just a week after a temperature record of 18.3ºC was registered in Antarctica, exceeding the previous record of 17.5ºC. Temperatures in the white continent have been measured since 1961, with the historical minimum set at -89.2ºC in 1983.