Tag Archives: glaciers

World

Glaciers in Yosemite and Africa will disappear by 2050, U.N. warns

Leave a comment

Comment

PARIS — Glaciers in at least one-third of World Heritage sites possessing them, including Yosemite National Park, will disappear by mid-century even if emissions are curbed, the U.N. Educational, Scientific and Cultural Organization warned in a new report Thursday.

Even if global warming is limited to just 1.5 degrees Celsius (2.7 degrees Fahrenheit), which now seems unlikely, all the glaciers in Yosemite and the ice patches in Yellowstone National Park, as well as the few glaciers left in Africa, will be lost.

Other glaciers can be saved only if greenhouse gas emissions “are drastically cut” and global warming is capped at 1.5 degrees Celsius, the Paris-based UNESCO warned in its report.

“This report is a call to action,” UNESCO Director-General Audrey Azoulay said in a statement and linked the report to United Nations Climate Change Conference, known as COP27, which is set to begin in Egypt next week. “COP27 will have a crucial role to help find solutions to this issue.”

The world’s melting glaciers are yielding up their secrets too quickly

About 50 of the organization’s more than 1,150 World Heritage sites have glaciers, which together constitute almost a tenth of the world’s glaciered area.

The almost 19,000 glaciers located at heritage sites are losing more than 60 billion tons of ice a year, which amounts to the annual water consumption of Spain and France combined, and accounts for about 5 percent of global sea-level rise, UNESCO said.

“Glaciers are retreating at an accelerated rate worldwide,” said Tales Carvalho Resende, a hydrology expert with UNESCO.

The organization described a “cycle of warming” in which the melting of glaciers causes the emergence of darker surfaces, which then absorb even more heat and speed up the retreat of ice.

Besides drastic cuts in emissions, the UNESCO report calls for better monitoring of glaciers and the use of early warning mechanisms to respond to natural disasters, including floods caused by bursting glacial lakes. Such floods have already cost thousands of lives and may have partly fueled Pakistan’s catastrophic inundations this year.

While there have been some local attempts to reduce melt rates — for example, by covering the ice with blankets — Carvalho Resende cautioned that scaling up those experiments “might be extremely challenging, because of costs but also because most glaciers are really difficult to access.”

Throughout history, glaciers have grown during very cold periods and shrunk when those stretches ended. The world’s last very cold period ended over 10,000 years ago, and some further natural melting was expected in Europe after the last “Little Ice Age” ended in the 19th century.

But as carbon dioxide emissions surged over the past century, human factors began to quicken what had been expected to be a gradual natural retreat. In Switzerland, glaciers lost a record 6 percent of their volume just this year.

While the additional melting has to some extent balanced out other impacts of climate change — for instance, preventing rivers from drying out despite heat waves — it is rapidly reaching a critical threshold, according to UNESCO.

In the Forcle Glacier in Switzerland, scientists are able to discover ancient artifacts where the land was once frozen over. (Video: Rick Noack/The Washington Post)

In its report, the organization writes that the peak in meltwater may already have been passed on many smaller glaciers, where the water is now starting to dwindle.

If the trend continues, the organization warned, “little to no base flow will be available during the dryer periods.”

The changes are expected to have major ramifications for agriculture, biodiversity, and urban life. “Glaciers are crucial sources of life on Earth,” UNESCO wrote.

“They provide water resources to at least half of humanity,” said Carvalho Resende, who cautioned that the cultural losses would also be immense.

Around the world, global warming is exposing ancient artifacts faster than they can be saved by archaeologists.

“Some of these glaciers are sacred places, which are really important for Indigenous peoples and local communities,” he said.

UNESCO cited the example of the centuries-old Snow Star Festival in the Peruvian Andes, which has already been impacted by ice loss. Spiritual leaders once shared blocks of glacier ice with pilgrims, but the practice was stopped when locals noticed the rapid retreat in recent years.

Sign up for the latest news about climate change, energy and the environment, delivered every Thursday

Small glaciers at low or medium altitudes will be the first to disappear. UNESCO said ice-loss rates in small glaciered areas “more than doubled from the early 2000s to the late 2010s.”

This matches observations from researchers who have studied the retreat of glaciers. Matthias Huss, a European glaciologist, said scientists had seen “very strong melting in the last two decades” in Switzerland.

At the same time, there are fewer and fewer places cold enough for glaciers to actually grow. “Nowadays, the limit where glaciers can still form new ice is at about 3,000 meters [about 9,840 feet],” he said, explaining that in recent decades that altitude has risen several hundred meters.

Read original article here

World

Glaciers at Yellowstone and Yosemite National Park on track to disappear in the next 30 years, report says

Leave a comment



CNN
 — 

The climate crisis is touching nearly every region of the world. But perhaps one of the most visible indicators of its impact is its effect on Earth’s iconic glaciers, a major source of freshwater supply. Glaciers have been melting at a breakneck pace in recent decades, leading to around 20% of global sea level rise since 2000.

Now researchers at the UN Educational, Scientific and Cultural Organization have found that glaciers in one-third of the planet’s most beautiful parks and protected areas are set to disappear by 2050 – whether or not global warming is slowed.

Among the glaciers on the brink of vanishing at World Heritage sites are those in two of the most visited and most beloved parks in the United States – Yellowstone National Park, which saw unprecedented flooding earlier this year, and Yosemite National Park.

The list also includes some of the largest and most iconic glaciers in Central Asia and Europe as well as the last remaining glaciers in Africa, namely Mount Kenya and Mount Kilimanjaro.

Glaciers at World Heritage sites shed around 58 billion tons of ice each year, UNESCO reports, which is equivalent to the total volume of water used annually in France and Spain combined. And these glaciers have already contributed nearly 5% of global sea level rise in the last 20 years.

The study provides the first global assessment of both the current and future scenario of glaciers in World Heritage sites, according to Tales Carvalho Resende, project officer at UNESCO’s natural heritage unit and author of the report.

“This report brings a very powerful message in the sense that World Heritage Sites are iconic places – places that are extremely important for humanity, but especially for local communities and Indigenous peoples,” Resende told CNN. “Ice loss and glacial retreat is accelerating, so this sends an alarming message.”

Only by limiting global warming to 1.5 degrees Celsius above preindustrial levels can we save glaciers at the other two-thirds of these parks, scientists report – a climate target that recent reports say the world is far from achieving. The global average temperature has already risen around 1.2 degrees since the industrial revolution.

Glaciers cover around 10% of land, providing fresh water supply for households, agriculture and industry downstream. Under normal conditions, they take as long as a millennium to fully form; each year, they gain mass through snow or rain, and lose mass by melting in the summer.

Melting glaciers may seem like a faraway problem, but Resende said it’s a serious global issue that can hit downstream communities hard. He highlighted Pakistan’s deadly floods this year, which left nearly one-third of the country underwater. Reports say the multiweek floods were likely triggered by a combination of heavier than usual monsoon rains and several glacial lake outbursts due to melting that followed the recent extreme heat that enveloped the region.

“As water melts, this water will accumulate in what we call glacial lakes; and as water comes, these glacial lakes might burst,” he said. “And this outburst can create catastrophic floods, which is something we can see very recently in Pakistan.”

Thomas Slater, a glaciologist at the University of Leeds in London, noted that these glaciers are contributing a small fraction of sea level rise compared to the amount of ice loss the Antarctic and Greenland ice sheets could generate. Researchers like Slater have already found those ice sheets to be the major contributors to global sea-level rise this century.

“While it’s sad to hear some of these glaciers could be lost, we should take hope in the fact that reducing emissions can save the majority of them and avoid disruption to the water supply of millions of people worldwide who live downstream,” Slater, who is not involved with the UN report, told CNN.

With the rate at which the climate crisis is accelerating, more water will be released from glaciers. In drought-stricken areas like the Western US, an increase in meltwater may be a good thing, but Resende said it is only temporary.

Once a glacier’s peak water – the maximum meltwater it contributes to the system – has been reached, annual runoff decreases as the glacier shrinks to the point where it’s no longer able to produce water supply.

According to the report, many small glaciers in the Andes, Central Europe and Western Canada either have already reached peak water or are expected to in the coming years. Meanwhile, in the Himalayas, annual glacier runoff is forecast to jump around 2050, before it plunges steadily afterward.

If countries fail to keep global warming under 1.5 degrees, or even 2 degrees, glaciers will only continue to recede, the report shows. In that future, places would see significant glacier runoff during the wet periods, with little to no flow to quench drier and hotter conditions.

“This is a hot topic currently in the research community – to see what will be the landscape after glacier melting,” Resende said. “Unfortunately, glaciers will keep melting because there’s always a delay. Even if we stop or drastically cut our emissions today, they will keep retreating because there’s this inertia – and it is extremely important that we manage to set up adaptation measures.”

The report comes as world leaders gather in Sharm el-Sheikh, Egypt, next week for the UN-brokered international climate negotiations, where the focus will be on getting countries to commit to stronger fossil fuel cuts that would limit global warming to 1.5 degrees. They will also discuss plans to adapt to worsening extreme weather events including heat waves, floods and storms.

“We need to really unite ourselves, to make as much as possible this 1.5 objective feasible,” Resende said. “The impacts might be irreversible, so this is really a pledge to take urgent action.”

Read original article here

Science

Next pandemic may come from melting glaciers, new data shows | Infectious diseases

Leave a comment

The next pandemic may come not from bats or birds but from matter in melting ice, according to new data.

Genetic analysis of soil and lake sediments from Lake Hazen, the largest high Arctic freshwater lake in the world, suggests the risk of viral spillover – where a virus infects a new host for the first time – may be higher close to melting glaciers.

The findings imply that as global temperatures rise owing to climate change, it becomes more likely that viruses and bacteria locked up in glaciers and permafrost could reawaken and infect local wildlife, particularly as their range also shifts closer to the poles.

For instance, in 2016 an outbreak of anthrax in northern Siberia that killed a child and infected at least seven other people was attributed to a heatwave that melted permafrost and exposed an infected reindeer carcass. Before this, the last outbreak in the region had been in 1941.

To better understand the risk posed by frozen viruses, Stéphane Aris-Brosou and her colleagues at the University of Ottawa in Canada collected soil and sediment samples from Lake Hazen, close to where small, medium and large amounts of meltwater from local glaciers flowed in.

Next, they sequenced RNA and DNA in these samples to identify signatures closely matching those of known viruses, as well as potential animal, plant or fungal hosts, and ran an algorithm that assessed the chance of these viruses infecting unrelated groups of organisms.

The research, published in Proceedings of the Royal Society B, suggested that the risk of viruses spilling over to new hosts was higher at locations close to where large amounts of glacial meltwater flowed in – a situation that becomes more likely as the climate warms.

The team did not quantify how many of the viruses they identified were previously unknown – something they plan to do in the coming months – nor did they assess whether these viruses were capable of triggering an infection.

However, other recent research has suggested that unknown viruses can, and do, loiter in glacier ice. For instance, last year, researchers at Ohio State University in the US announced they had found genetic material from 33 viruses – 28 of them novel – in ice samples taken from the Tibetan plateau in China. Based on their location, the viruses were estimated to be approximately 15,000 years old.

In 2014, scientists at France’s National Centre for Scientific Research in Aix-Marseille managed to revive a giant virus they isolated from Siberian permafrost, making it infectious again for the first time in 30,000 years. The study’s author, Jean-Michel Claverie, told the BBC at the time that exposing such ice layers could be “a recipe for disaster”.

Even so, Aris-Brosou’s team cautioned that predicting a high risk of spillover was not the same as predicting actual spillovers or pandemics. “As long as viruses and their ‘bridge vectors’ are not simultaneously present in the environment, the likelihood of dramatic events probably remains low,” they wrote.

On the other hand, climate change is predicted to alter the range of existing species, potentially bringing new hosts into contact with ancient viruses or bacteria.

“The only take-home that we can confidently put forward is that as temperatures are rising, the risk of spillover in this particular environment is increasing,” said Aris-Brosou. “Will this lead to pandemics? We absolutely don’t know.”

Also unclear is whether the potential for host switching identified in Lake Hazen is unique within lake sediments. “For all we know, it could be the same as the likelihood of host switching posed by viruses from the mud in your local pond,” said Arwyn Edwards, the director of the Interdisciplinary Centre for Environmental Microbiology at Aberystwyth University.

However, “we do urgently need to explore the microbial worlds all over our planet to understand these risks in context,” he said. “Two things are very clear now. Firstly, that the Arctic is warming rapidly and the major risks to humanity are from its influence on our climate. Secondly, that diseases from elsewhere are finding their way into the vulnerable communities and ecosystems of the Arctic.”

Read original article here

Science

Scientists are listening to glaciers to discover the secrets of the oceans

Leave a comment

Editor’s Note: Call to Earth is a CNN initiative in partnership with Rolex. Michel Andre is a Rolex Awards Laureate.



CNN
 — 

Snap, crackle, pop: the sound of a glacier. The large bodies of densely packed ice may look like motionless masses, but they flow and fracture and grow and shrink, and these processes are anything but silent.

In fact, glacial ice is famously fizzy. Cubes of it have long been used on cruise ships in Alaska, added to a Scotch or a gin and tonic, as the ice gives off a unique hiss when it slowly releases the highly pressurized air that has been trapped there for hundreds and sometimes thousands of years.

But the sounds made by glaciers can be used for more than just novelty ice cubes. With many glaciers around the world shrinking because of the climate crisis, scientists are looking to analyze these noises to predict exactly how quickly ice is melting and what that could mean for sea-level rise.

“Glaciers are undergoing rapid retreat as the atmosphere and the ocean warms,” says Grant Deane, research oceanographer at Scripps Institution of Oceanography in San Diego, California. “If we want to (forecast) sea-level rise … we need a way of monitoring these glacial systems and underwater sound could be an important and interesting way of doing it.”

Deane, who has worked in the field of underwater sound for more than two decades, explains that there are two main processes by which glaciers retreat, both of which make a distinct noise. There is the “bright, energetic sound of bubbles exploding into the water as ice melts,” he says, which he compares to fireworks or sizzling bacon. And there is the “deep, ominous rumble” of a calving event, when a block of ice breaks off from the end of a glacier, which he says sounds like extended thunder.

Both events happen in the boundary where the ice meets the ocean, typically a very dangerous area for humans. That’s one reason why acoustics, which can be monitored from afar, could be so valuable.

Using underwater sound to predict ice melt is still a relatively new field. In 2008, distinguished oceanographer Wolfgang Berger co-authored a piece in the scientific journal Nature Geoscience that proposed using hydroacoustics (sound in water) to monitor Greenland’s ice sheets. That inspired Deane – who was already listening to the ocean’s breaking waves to understand how gases transfer from sea to air – to turn his ears to glaciers.

“As the ocean rises, it’s going to impact so much of our civilization. We need to be able to forecast the stability of these ice sheets so that we can plan well and live well as our environment changes,” he says.

Using underwater microphones to record the sound of calving events in Hans Glacier, at Svalbard, northern Norway, along with time lapse photography, Deane and Oskar Glowacki from the Polish Academy of Sciences demonstrated that the amount of ice loss can be estimated from the noise produced when an iceberg crashes into the ocean. Their findings were published in the Cryosphere journal in 2020.

Air bubbles could also reveal vital information. “If we can count how many bubbles are coming out of the ice in any specified unit of time, we can figure out how much ice has melted,” says Deane. That could be key to understanding how much ice will melt in the future.

Related: Nuclear power could be the future of expedition cruises

It’s simple as an idea, but far from simple in practice. The volume of the air bubbles changes depending on how they are released, Deane says, and there is the possibility that noise levels will vary between glaciers because of the geology and local conditions.

But Deane’s research, predominantly focused on Svalbard, has shown that the intensity of the sound generated by air bubbles increases as the water temperature increases, showing that volume can be an indicator of ice melt. “Every expedition, we get closer to the actual answer where we can turn those signals into the numbers that we need,” he says.

Several different, and some much more developed, methods already exist to study glaciers, including seismology, satellite photography, underwater sonar and ice-penetrating radar. But Deane insists that acoustics can supplement these methods and offers some advantages.

Hydrophones (underwater microphones) can be deployed in glacier fjords and monitored remotely over long timescales, he says, and unlike satellite observations, which don’t work for the six months of the year when it’s dark in the north and south poles, acoustic technology operates all year round and is cheaper than other methods.

Listening to glaciers not only shows us how they’re melting – it could also teach us more about the marine ecosystem. Glaciologist Erin Pettit has used acoustic technology to determine that glacier fjords are some of the loudest places in the ocean thanks to the constant hiss of air bubbles released as the ice melts, and that noise could provide refuge for marine mammals.

Pettit and her team of researchers observed how seals would swim up to glacier bays in Alaska and Antarctica, possibly to protect themselves from predatory whales that don’t like loud noises.

“The ecosystem changes as the soundscape changes,” she says, adding that if the volume goes up or down there will be a ripple effect. “If the glacier pulls up out of the fjord and there’s less ice in the water itself, the sound will slowly decrease … then it’s no longer noisy and no longer a safe place for the seals.” In this way, acoustic measurements could offer insight into the decline of seal populations in these areas.

Pettit notes that the field of acoustics is still in its early days, and to measure long-term change in glaciers, scientists will need to collect more sound data. But she believes the technology holds great promise.

“Sound doesn’t give us all the answers – but it does provide a relatively low-cost, easy to deploy means to capture the whole fjord and glacier environment,” she says. If hydrophones were deployed over a long period, they could help scientists understand a glacier’s “normal” noise levels, and detect abnormal sounds which might indicate instability, she adds.

Related: Scientists make major breakthrough in race to save Caribbean coral

Deane’s goal is to follow in the late Wolfgang Berger’s footsteps and set up long-term acoustical monitoring stations in Greenland to help track the stability of its ice sheet, which could raise sea levels by 25 feet if it were to completely melt.

“I want recording systems running south to north around the Greenland glaciers,” he says. “The first job is to make sure we can understand the sounds. If we can prove that we can do that, then we can make the case that we should be listening continuously to these glaciers.”

“The future of the oceans depends on us (humans),” he adds. “We need to start listening to what they are telling us.”

Read original article here

World

‘Outbursts’ from Pakistan’s melting glaciers have tripled this year and are worsening floods

Leave a comment

The country’s chief meteorologist has warned that this year alone, Pakistan has seen triple the usual amount of glacial lake outbursts — a sudden release of water from a lake fed by glacier melt — that can cause catastrophic flooding.

Sardar Sarfaraz from Pakistan’s Meterological Department said Thursday that there have been 16 such incidents in the country’s northern Gilgit-Baltistan region in 2022, compared with just five or six seen in previous years.

“Such incidents occur after glaciers melt due to [a] rise in temperature,” Sarfaraz told Reuters, adding: “Climate change is the basic reason for such things.”

Melting glaciers is one of the clearest, most visible signs of the climate crisis and one of its most direct consequences.

It’s not yet clear how much Pakistan’s current flooding crisis might be connected to glacial melt. But unless planet-warming emissions are reined in, Sarfaraz suggests that the country’s glaciers will continue to melt at speed.

“Global warming will not stop until we curtail greenhouse gasses and if global warming does not stop, these climate change effects will be on the rise,” he said.

Pakistan is responsible for less than 1% of the world’s planet-warming gases, according to European Union data, yet it is the eighth most vulnerable nation to the climate crisis, according to the Global Climate Risk Index.

That vulnerability has been on display for months, with record monsoon rains and melting glaciers in the country’s northern mountains triggering floods that have killed at least 1,191 people — including 399 children — since mid-June.

New flooding fears

On Thursday, southern Pakistan braced for more flooding as a surge of water flowed down the Indus river, compounding the devastation in a country a third of which is already inundated by the climate change induced disaster.

The United Nations has appealed for $160 million to help with what it has called an “unprecedented climate catastrophe.”

“We’re on a high alert as water arriving downstream from northern flooding is expected to enter the province over the next few days,” the spokesman of the Sindh provincial government, Murtaza Wahab, told Reuters.

Wahab said a flow of some 600,000 cubic feet per second was expected to swell the Indus, testing its flood defences.

Pakistan has received nearly 190% more rain than the 30-year average in the quarter from June to August, totalling 390.7mm (15.38 inches).

Sindh, with a population of 50 million, has been hardest hit, getting 466% more rain than the 30-year average.

Some parts of the province look like an inland sea with only occasional patches of trees or raised roads breaking the surface of the murky flood waters.

Hundreds of families have taken refugee on roads, the only dry land in sight for many of them.

Villagers rushed to meet a Reuters news team passing along one road near the town of Dadu on Thursday, begging for food or other help.

The floods have swept away homes, businesses, infrastructure and roads. Standing and stored crops have been destroyed and some two million acres (809,371 hectares) of farm land inundated.

The government says 33 million people, or 15% of the 220 million population, have been affected.

The National Disaster Management Authority said some 480,030 people have been displaced and are being looked after in camps but even those not forced from their homes face peril.

“More than three million children are in need of humanitarian assistance and at increased risk of waterborne diseases, drowning and malnutrition due to the most severe flooding in Pakistan’s recent history,” the UN children’s agency warned.

The World Health Organization said that more than 6.4 million people were in dire need of humanitarian aid.

Aid has started to arrive on planes loaded with food, tents and medicines, mostly from China, Turkey and United Arab Emirates.

Aid agencies have asked the government to allow food imports from neighboring India, across a largely closed border that has for decades been a front line of confrontation between the nuclear armed rivals.

The government has not indicated it is willing to open the border to Indian food imports.

CNN’s Angela Dewan and Azaz Syed contributed reporting.

Read original article here

Science

Zombie ice from Greenland will raise sea level 10 inches

Leave a comment

Greenland’s rapidly melting ice sheet will eventually raise global sea level by at least 10.6 inches (27 centimeters) — more than twice as much as previously forecast — according to a study published Monday.

That’s because of something that could be called zombie ice. That’s doomed ice that, while still attached to thicker areas of ice, is no longer getting replenished by parent glaciers now receiving less snow. Without replenishment, the doomed ice is melting from climate change and will inevitably raise seas, said study co-author William Colgan, a glaciologist at the Geological Survey of Denmark and Greenland.

“It’s dead ice. It’s just going to melt and disappear from the ice sheet,” Colgan said in an interview. “This ice has been consigned to the ocean, regardless of what climate (emissions) scenario we take now.”

Study lead author Jason Box, a glaciologist at the Greenland survey, said it is “more like one foot in the grave.”

The unavoidable ten inches in the study is more than twice as much sea level rise as scientists had previously expected from the melting of Greenland’s ice sheet. The study in the journal Nature Climate Change said it could reach as much as 30 inches (78 centimeters). By contrast, last year’s Intergovernmental Panel on Climate Change report projected a range of 2 to 5 inches (6 to 13 centimeters) for likely sea level rise from Greenland ice melt by the year 2100.

What scientists did for the study was look at the ice in balance. In perfect equilibrium, snowfall in the mountains in Greenland flows down and recharges and thickens the sides of glaciers, balancing out what’s melting on the edges. But in the last few decades there’s less replenishment and more melting, creating imbalance. Study authors looked at the ratio of what’s being added to what’s being lost and calculated that 3.3% of Greenland’s total ice volume will melt no matter what happens with the world cutting carbon pollution, Colgan said.

“I think starving would be a good phrase,” for what’s happening to the ice, Colgan said.

One of the study authors said that more than 120 trillion tons (110 trillion metric tons) of ice is already doomed to melt from the warming ice sheet’s inability to replenish its edges. When that ice melts into water, if it were concentrated only over the United States, it would be 37 feet (11 meters) deep.

The figures are a global average for sea level rise, but some places further away from Greenland would get more and places closer, like the U.S. East Coast, would get less. Although 10.6 inches may not sound like much, this would be over and above high tides and storms, making them even worse, so this much sea level rise “will have huge societal, economic and environmental impacts,” said Ellyn Enderlin, a geosciences professor at Boise State University, who wasn’t part of the study.

“This is a really large loss and will have a detrimental effect on coastlines around the world,” said NYU’s David Holland who just returned from Greenland, but is not part of the study.

This is the first time scientists calculated a minimum ice loss — and accompanying sea level rise — for Greenland, one of Earth’s two massive ice sheets that are slowly shrinking because of climate change from burning coal, oil and natural gas. Scientists used an accepted technique for calculating minimum committed ice loss, the one used on mountain glaciers for the entire giant frozen island.

Pennsylvania State University glaciologist Richard Alley, who wasn’t part of the study but said it made sense, said the committed melting and sea level rise is like an ice cube put in a cup of hot tea in a warm room.

“You have committed mass loss from the ice,” Alley said in an email. “In the same way, most of the world’s mountain glaciers and the edges of Greenland would continue losing mass if temperatures were stabilized at modern levels because they have been put into warmer air just as your ice cube was put in warmer tea.”

Time is the key unknown here and a bit of a problem with the study, said two outside ice scientists, Leigh Stearns of the University of Kansas and Sophie Nowicki of the University of Buffalo. The researchers in the study said they couldn’t estimate the timing of the committed melting, yet in the last sentence they mention, “within this century,” without supporting it, Stearns said.

Colgan responded that the team doesn’t know how long it will take for all the doomed ice to melt, but making an educated guess, it would probably be by the end of this century, or at least by 2150.

Colgan said this is actually all a best case scenario. The year 2012 (and to a different degree 2019 ) was a huge melt year, when the equilibrium between adding and subtracting ice was most out of balance. If Earth starts to undergo more years like 2012, Greenland melt could trigger 30 inches (78 centimeters) of sea level rise, he said. Those two years seem extreme now, but years that look normal now would have been extreme 50 years ago, he said.

“That’s how climate change works,” Colgan said. “Today’s outliers become tomorrow’s averages.”

___

Follow AP’s climate and environment coverage at https://apnews.com/hub/climate-and-environment

___

Follow Seth Borenstein on Twitter at @borenbears

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.



Read original article here

World

Alpine glacier chunk detaches, killing at least 6 hikers

Leave a comment

ROME — A large chunk of an Alpine glacier broke loose Sunday afternoon and roared down a mountainside in Italy, sending ice, snow and rock slamming into hikers on a popular trail on the peak and killing at least six and injuring eight, authorities said.

There could be about 10 people missing, Civil Protection official Gianpaolo Bottacin was quoted as saying by the online version of Italian daily Corriere della Sera. But Bottacin later told state television that it wasn’t yet possible to provide a firm number.

The glacier, in the Marmolada range, is the largest in the Dolomite mountains in northeastern Italy and people ski there in the winter. But the glacier has been rapidly melting away in recent years.

Experts at Italy’s state-run CNR research center, which has a polar sciences institute, says the glacier won’t exist anymore in the next 25-30 years and most of its volume is already gone. The Mediterranean basin, shared by southern Europe, the Middle East and northern Africa, has been identified by U.N. experts as a “climate change hot spot,” likely to suffer heat waves and water shortages, among other consequences.

By Sunday evening, officials were still working to determine just how many hikers were in the area when the ice avalanche struck, said Walter Milan, a spokesperson for the national Alpine rescue corps who provided the death and injury toll.

Rescuers were checking license plates in the parking lot as part of checks to determine how many people might be unaccounted for, a process that could take hours, Milan told The Associated Press by telephone.

“We saw dead (people) and enormous chunks of ice, rock,” exhausted-looking rescuer Luigi Felicetti told Italian state TV.

Nationalities or ages of the dead weren’t immediately available, Milan said. Of the eight hospitalized survivors, two were in grave condition, authorities said.

The fast-moving avalanche “came down with a roar the could be heard at great distance,” local online media site ildolomiti.it said.

Earlier, the National Alpine and Cave Rescue Corps tweeted that the search of the involved area of the Marmolada peak involved at least five helicopters and rescue dogs.

Temporarily, the search for any more victims or missing was halted while rescuers evaluate the risk that more of the glacier could break off, Walter Cainelli, after conducting a rescue mission with a search dog, told state television.

Rescuers said blocks of ice were continuing to tumble down. In early evening, a light rain began to fall.

The SUEM dispatch service, which is based in the nearby Veneto region, said 18 people who were above the area where the ice struck would be evacuated by the Alpine rescue corps.

But Milan said some on the slope might be able to get down by themselves, including by using the peak’s cable car.

SUEM said the avalanche consisted of a “pouring down of snow, ice and rock.” The detached section is know as a serac, or pinnacle of ice.

Marmolada, towering about 3,300 meters (about 11,000 feet), is the highest peak in the eastern Dolomites, offering spectacular views of other Alpine peaks.

The Alpine rescue service said in a tweet that the segment broke off near Punta Rocca (Rock Point), “along the itinerary normally used to reach the peak.”

It wasn’t immediately clear what caused the section of ice to break away and rush down the peak’s slope. But the intense heat wave gripping Italy since late June could be a factor.

“The temperatures of these days clearly had influence” on the glacier’s partial collapse, Maurizio Fugatti, the president of Trento Province, which borders Marmolada, told Sky TG24 news.

But Milan stressed that high heat, which soared unusually above 10 C (50 F) on Marmolada’s peak in recent days, was only one possible factor in Sunday’s tragedy.

“There are so many factors that could be involved,” Milan said. Avalanches in general aren’t predictable, he said, and heat’s influence on a glacier “is even more impossible to predict.”

In separate comments to Italian state television, Milan called the recent temperatures “extreme heat” for the peak. “Clearly it’s something abnormal.”

The injured were flown to several hospitals in the regions of Trentino-Alto Adige and Veneto, according to rescue services.

Read original article here

Science

Nearly 1,000 Microbe Species Have Just Been Discovered in ‘Extreme’ Tibetan Glaciers

Leave a comment

Living as a microbe on the Tibetan Plateau isn’t easy. Frigid temperatures, high levels of solar radiation, not a lot to eat, and you’d regularly get frozen and then thawed depending on the time of year.

 

So, it’s a bit of a surprise that in these ‘extreme environmental conditions’ scientists have discovered 968 species featuring a hugely diverse range of microbes. The finding comes courtesy of the first dedicated genome catalog of the glacier ecosystem.

“The surfaces of glaciers support a diverse array of life, including bacteria, algae, archaea, fungi, and other microeukaryotes. Microorganisms have demonstrated the ability to adapt to these extreme conditions and contribute to vital ecological processes,” writes the team in their new paper.

“Glacier ice can also act as a record of microorganisms from the past, with ancient (more than 10,000 years old) airborne microorganisms being successfully revived. Therefore, the glacial microbiome also constitutes an invaluable chronology of microbial life on our planet.”

The researchers honed in on one specific group of glaciers – the Tibetan Plateau. This 2.5 million square kilometer region is an important water source for the surrounding areas in Asia and has been particularly affected by climate change, with over 80 percent of glaciers having started to retreat.

Not only is it important for us to know which microbes are up there (just in case they could be a problem for humans and the ecosystem as the ice melts), but if we don’t note what species are currently there, climate change might soon make them lost to history.

 

“Here we present the first, to our knowledge, dedicated genome and gene catalog for glacier ecosystems, comprising 3,241 genomes and metagenome-assembled genomes and 25 million non-redundant proteins from 85 Tibetan glacier metagenomes and 883 cultivated isolates,” the team, led by Lanzhou University ecologist Yongqin Liu, writes in their paper.

The researchers undertook a mammoth effort, sampling snow, ice, and dust from 21 Tibetan glaciers between 2016 and 2020. They used metagenomic methods on the samples to collect all of the genetic material present; they also cultured some of the microbes in a lab to find out more about them and to retrieve a higher proportion of their genome.

Excitingly, 82 percent of the genomes were novel species. A whopping 11 percent of species were found only in one glacier, while 10 percent were located in almost all the glaciers studied.

The project has become what the researchers are calling the ‘Tibetan Glacier Genome and Gene’ (TG2G) catalog, and hopefully this will be of use for researchers in the future, with new additions as more species are found.

“The TG2G catalog offers a database and a platform for archiving, analysis and comparison of glacier microbiomes at the genome and gene levels. It is particularly timely as the glacier ecosystem is threatened by global warming, and glaciers are retreating at an unprecedented rate,” the team writes.

“We envisage that the catalog will form the basis of a comprehensive global repository for glacial microbiome data.”

The research has been published in Nature Biotechnology.

 

Read original article here

Science

Unusually cold ‘Blue Blob’ is slowing the rapid melting of Iceland’s glaciers, but not for long

Leave a comment

A recent slowdown in the melting of Iceland’s glaciers is likely caused by a patch of unusually cold water in the North Atlantic Ocean, known as the “Blue Blob,” “according to a new study. (Image credit: Finnur Pálsson)

The “Blue Blob,” an unusually cold patch of water in the Arctic, has halved the rate at which Iceland’s glaciers are melting, but a new study reveals that the effects of climate change will catch up to the massive ice chunks if temperatures are not kept in check.    

The Blue Blob is an undefined area of the North Atlantic Ocean located south of Iceland and Greenland. At its peak coldness, in 2015, the Blue Blob was 2.5 degrees Fahrenheit (1.4 degrees Celsius) colder than the surrounding waters. Before the emergence of the Blue Blob, Iceland’s glaciers were losing a staggering 11 gigatons of ice every year due to melting. But since the cool patch emerged in 2011, that rate has more than halved to a slightly less worrying 5 gigatons a year ​​— even though the rest of the Arctic is warming four times faster than anywhere else on Earth, according to a statement from the American Geophysical Union.      

In the new study, published online Jan. 24 in the journal Geophysical Research Letters, researchers used climate models to predict how long the Blue Blob could continue to slow the glaciers’ rampant melting. They found that the rising temperatures will overcome the cooling effect and match rapid melting rates seen in nearby Greenland and the Norwegian archipelago Svalbard by the mid-2050s. 

Related: 10 things you need to know about Arctic sea ice

Researchers say this finding is important because it improves our understanding of trends throughout the Arctic. “It’s crucial to have an idea of the possible feedbacks in the Arctic, because it’s a region that is changing so fast,” lead author Brice Noël, a climate scientist at Utrecht University in the Netherlands, said in the statement. “It’s important to know what we can expect in a future warmer climate.”

The ‘Blue Blob’ can be seen in this map (below Greenland and Iceland) showing the average sea surface temperature changes since 2020 (temperatures in degrees Celsius). (Image credit: Goddard Institute of Space Studies Surface Temperature Analysis (v4))

Iceland currently hosts four major ice caps each larger than 193 square miles (500 square kilometers), seven smaller ice masses each larger than 4 square miles (10 square km) and around 250 other glaciers smaller than 4 square miles. In total, the volume of ice on the island nation is estimated to be around 816 cubic miles (3,400 cubic km), which would be enough to raise global sea levels by 0.35 inches (9 millimeters) if it completely melted, the researchers wrote in the paper. This is the equivalent to around three times the current global sea rise we are experiencing every year, according to the Smithsonian Institute.

Almost all of Iceland’s glaciers terminate on land, meaning they do not come into contact with the sea. Therefore, the rate at which they melt is dependent on their surface mass balance, which is the difference between ice gained from winter snowfall and ice lost from meltwater runoff in the summer. However, the Blue Blob is so cold that it decreases the temperature of the air that flows over it, which then cools the atmosphere surrounding Iceland and, in turn, reduces the surface mass balance of its ice masses, meaning less ice is lost.

Using the latest climate prediction models and local atmospheric temperature readings dating back to the 1990s, the team pinpointed when rising temperatures caused by climate change would outweigh the influence of the Blue Blob on Iceland’s surface mass balance. The researchers estimated that by 2100, a third of Iceland’s glaciers may be gone and that by 2300, there likely will be no glaciers left in the country. 

The researchers verified the results of their models using depth measurements from Iceland’s glaciers, collected by colleagues at the University of Iceland since the 1990s. (Image credit: Finnur Pálsson)

The researchers’ approach could be used to better understand the melting rates of glaciers in other places, such as the Himalayas and Patagonia, Fiamma Straneo, an oceanographer at the Scripps Institution of Oceanography in California who was not involved in the study, said in the statement.

Scientists are still unsure why the Blue Blob is so much colder than the surrounding waters. Some researchers think it is part of natural variability in sea-surface temperatures in the Arctic that has increased the amount of upwelling of cold water from the deep sea. Others think climate change has disrupted surface currents that push warmer water into the Arctic from tropical regions in the Atlantic. 

Regardless of how the Blue Blob came to be, its cooling effect on Iceland will not last forever, and if left unchecked, climate change will cause the total disappearance of Iceland’s glaciers in the not-too-distant future. 

“In the end, the message is still clear,” Noël said in the statement. “The Arctic is warming fast. If we wish to see glaciers in Iceland, then we have to curb the warming.”

Originally published on Live Science.

Read original article here

World

Water Supplies From Glaciers May Peak Sooner Than Anticipated

Leave a comment

The world’s glaciers may contain less water than previously believed, a new study has found, suggesting that freshwater supplies could peak sooner than anticipated for millions of people worldwide who depend on glacial melt for drinking water, crop irrigation and everyday use.

The latest findings are based on satellite images taken during 2017 and 2018. They are a snapshot in time; scientists will need to do more work to connect them with long-term trends. But they imply that further global warming could cause today’s ice to vanish in many places on a shorter timeline than previously thought.

In the tropical Andes, for instance, the study estimated glacier volume to be 27 percent less than the scientific consensus as of a few years ago. In parts of Russia and northern Asia, glacier volume was 35 percent smaller, the study found.

Worldwide, the study found 11 percent less ice in the glaciers than had been estimated earlier. In the high mountains of Asia, however, it found 37 percent more ice, and in Patagonia and the central Andes, 10 percent more.

The new estimates come from a more detailed and realistic digital reconstruction of Earth’s 215,000 glaciers than had been possible before, said Romain Millan, a geophysicist at the Institute of Environmental Geosciences in Grenoble, France, and lead author of the study, which was published on Monday in the journal Nature Geoscience.

Even so, “we still have lots of uncertainty in some regions,” Dr. Millan said, mostly because of the scarcity of on-the-ground measurements, which help to inform any digital reconstruction. Those regions, including the Andes and the Himalayas, “are the ones where people rely on fresh water coming from glaciers,” he said.

The melting of glaciers is threatening livelihoods and reshaping landscapes in North America, Europe, New Zealand and many places in between.

In the upper Indus basin of the Himalayas, which straddles Afghanistan, China, India and Pakistan, glacial melt accounts for nearly half of river flow. Yet logistical and political challenges mean scientists can monitor only a small share of the Himalayan glaciers, said Anjal Prakash, a water expert at the Indian School of Business in Hyderabad who did not work on the new study.

“It’s a data-deficient region,” Dr. Prakash said. “Countries do not cooperate. They don’t share information with each other.”

With 1.5 billion people benefiting from the water and other resources of the Himalayas, while also facing growing risks of severe floods, the region “is just waiting for a disaster to happen,” Dr. Prakash said.

As glaciers have melted, they have contributed to rising global sea levels. The new study suggests that, all together, they could add 10 inches to the oceans instead of the foot or so that was estimated earlier. Either way, it is small compared with what the melting of Greenland and Antarctica could add to sea levels in the far future if the planet heats to catastrophic levels.

To produce their new estimates of glacier dimensions, Dr. Millan and his colleagues combined more than 811,000 satellite images to clock the speeds at which the glaciers’ surfaces are moving. Glaciers may look like solid, unchanging masses, but in fact, they are constantly in motion: sliding across the terrain; deforming under their own weight; flowing, syrup-like, down valleys. This movement is a clue to the amount of ice that is locked inside.

“The thickness of the glacier controls how fast it moves,” said Daniel Farinotti, a glaciologist at the Swiss university ETH Zurich who did not work on the new study. “And so, vice versa, if you know how fast it moves, you can say something about the thickness.”

The high resolution of the satellite images allowed Dr. Millan and his colleagues to capture fine variations in the glaciers’ thickness, such as narrow troughs in the ground underneath. They could map small ice caps in South America, Europe and New Zealand that had never been mapped before.

In certain ways, scientists understand less about some of the glaciers draped over the world’s mountains than they do about the much larger ice sheets of Greenland and Antarctica, said Mathieu Morlighem, an earth scientist at Dartmouth College who worked on the new study.

Only a few thousand glaciers worldwide have been measured on-site. In places like North America, the balmier climate means more pockets of water in the glaciers, which can thwart radar measurements. Compared with the giant ice sheets, where fast-moving ice has smoothed the underlying bedrock over time, the terrain beneath mountain glaciers can be “just so complex,” Dr. Morlighem said, making it harder to gauge their dimensions.

“Just 10, 15 years ago, we barely knew the area of the glaciers,” said Regine Hock, a geoscientist at the University of Oslo in Norway who was not involved in the new research. Estimates of glacier volume were “very, very rough,” she said.

Today’s “data revolution” is helping scientists make better predictions about local and regional water resources, even if the big picture globally — that the glaciers will thin substantially during this century — is unlikely to change much, Dr. Hock said. “There is only so much ice,” she said, “and then it’s gone.”

Read original article here

The Ultimate News Site