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A big chunk of ice has broken away from the Greenland ice sheet and the Arctic’s largest remaining ice shelf- called 79N, or Nioghalvfjerdsfjorden- in north-east Greenland. 

The piece that has broken off covers about 110 sq km. The Nioghalvfjerdsfjorden is roughly 1 600 sq km and is the floating front end of the northeast Greenland Ice Sheet, where it flows into the ocean. The glacier splits into two pieces, with a small offshoot to the north; it is this offshoot, called Spalte Glacier, that has disintegrated. 

The loss is further evidence of the advancing climate crisis and the changes happening in the region and to the Greenland Ice Sheet. According to Dr Jenny Turton, the atmosphere in the region has warmed by about 3 degrees Celsius since 1980. 

Satellite images show that these higher air temperatures in the region can be seen in the number of melt ponds that sit on top of the shelf ice. This water is problematic for ice platforms because if it fills crevasses, it can help to open them up. The water will push down on the fissures, moving them to the base of the shelf in a process known as hydrofracturing, which weakens the ice shelf. Warmer sea temperatures in the region mean that ice is probably being melted from beneath as well. 

greenland ice sheet n79

Professor Jason Box from the Geological Survey of Denmark and Greenland, says, “79N became the ‘largest remaining Arctic ice shelf’ only fairly recently, after the Petermann Glacier in northwest Greenland lost a lot of area in 2010 and 2012. What makes 79N so important is the way it’s attached to the interior ice sheet, and that means that one day- if the climate warms as we expect- this region will probably become one of the major centres of action for the deglaciation of Greenland.” He believes that 79N will likely disintegrate from the middle, but says that this could happen in anywhere from 10 to 20 years. 

July saw another large ice shelf structure in the Arctic lose a large amount of area; the last fully intact ice shelf in Canada in the Arctic collapsed, losing about 40% of its area over a two-day period. The ice shelf is now 106 sq km in size, after 80 sq km broke off from the Milne Ice Shelf. The Milne was the largest intact remnant from a wider shelf feature that covered 8 600 sq km at the start of the 20th century.

Further, the Greenland ice sheet lost a record amount of ice in 2019: an average of a million tons per minute throughout the year.

You might also like: Greenland Ice Sheet Lost 1 Million Tons of Ice Per Minute In 2019- Satellite Data

The climate crisis is heating the Arctic region at double the rate than at lower latitudes, and the Greenland ice sheet will be one of the biggest contributors to sea level rise, which is already affecting coastline cities around the world.

Featured image by: Flickr

According to satellite data, the Greenland ice sheet lost a record amount of ice in 2019: an average of a million tons per minute throughout the year. The climate crisis is heating the Arctic region at double the rate than at lower latitudes, and the Greenland ice sheet will be one of the biggest contributors to sea level rise, which is already affecting coastline cities around the world.

Published in the journal Communications Earth & Environment, the research used data from NASA’s Grace satellites, which take gravity measurement and essentially weigh the mass of ice in Greenland. The researchers say that the scale of the 2019 loss was likely to be the biggest in centuries. 

The Greenland ice sheet shrank by 600 billion tons in 2019. This, according to satellite data that has been collected since 2003, was more than double the annual average since then of 255 billion tons. Weather data and computer models allow for losses to be calculated back to 1948. Almost 96% of the ice sheet underwent melting at some point in 2019, compared with an average of 64% between 1981 and 2010. The researchers add that of record melt years, the top five has happened in the last 10 years. 

The researchers attributed this massive ice loss in 2019 to “blocking patterns” of weather that kept warm air over Greenland for longer, occurrences which are becoming more frequent as the climate crisis accelerates. This pattern also caused low snowfall, which means that little ice was added to the sheet. 

You might also like: Releasing Herds of Animals into the Arctic Could Help Fight Climate Change, Study Finds

However, the researchers found that in 2017 and 2018, there was unusually low ice loss, as this block pattern was reversed. This led to cold, snowy conditions over Greenland. However, they stress that ice was still lost from the ice sheet, and that cold years do not make up for the hot ones. 

Ingo Sasgen of the Alfred Wegener Institute in Bremerhaven, Germany, who led the analysis, says, “2019 was really shocking and depressing in terms of the numbers. But it’s also not very surprising, because we had other strong melt years in 2010 and 2012, and  expect we will see more and more.” 

Sasgen expresses further concern about feedback loop mechanisms that increase ice loss, like meltwater weakening the ice sheet and exacerbating its fall into the ocean. Warmer temperatures also melt the white snow on top of the sheet, revealing darker ice below, which absorbs more of the sun’s heat. 

If the entire Greenland ice sheet melts, sea level would rise by six metres. However, the researchers say that cutting carbon emissions will reduce the sea level rise from the ice sheet, which will allow those living near coasts to move away. 

Secondly, as glaciers retreat, they lose contact with warmer ocean waters and therefore melt less, and the melting of the sheet with warm air will take centuries, during which time the rise in global temperatures may be reversed. 

Featured image by: NASA Handout/ EPA

Glaciers and ice sheets currently cover around 10% of the Earth’s surface and are vital for shaping its physical landscape, reflecting intense solar radiation and supplying many people around the world with freshwater. Until recently, however, one characteristic of this environment has remained largely overlooked. What are algae blooms and how are they affecting the landscape?

Algae blooms living on the surface of the south-west coast of the Greenland Ice Sheet (GrIS) are causing darkening of the sheet, leading to increased rates of melting not currently being incorporated into melt rate models.

Glaciers and ice sheets are extremely dynamic ecosystems, capable of hosting abundant and diverse microbial life. Areas of the Earth in which water is found in a solid, frozen form are now termed the Cryosphere, which is considered one of the Earth’s five biospheres. Due to extreme and harsh conditions, particularly in the Arctic and Antarctic, microbial abundance, diversity and activity in these environments have been given little global prominence.  

Microbial life has now been documented in most areas of glaciers and ice sheets, including at the bedrock-ice interface, on the ice surface and inside the ice itself. Most initial research focused on microbial communities living at the bedrock-ice interface due to their influence on nutrient export to fjord and ocean environments. Surface ice environments, comprised of snow packs, bare ice, lakes and streams, have recently begun to take centre stage as microbial communities thriving in these habitats have drastically changed the physical appearance of glaciers and ice sheets worldwide. Areas of high microbial abundance and activity, known as cryoconite holes, have quickly become the primary focus of attention in surface ice environments. Cryoconite is a dark substance now found on most glacier and ice sheet surfaces worldwide, with areas of high abundance described as having the appearance of swiss cheese. 

It wasn’t until 2012 that scientists discovered a habitat other than cryoconite holes: the ice surface itself. A study of the GrIS found that the top two centimetres of the ice surface hosts abundant microbial life, dominated mainly by Streptophyta algae, now termed glacier algae.  

Prior to this finding, satellite imagery revealed a significant annual darkening occurring since 2000 on the surface of the GrIS, on an area about 20-30 km inland and 50 km wide, now known as the ‘Dark Zone’. Many scientists initially attributed this darkening to common light-absorbing particles such as atmospheric dust, black carbon from the burning of fossil fuels, dust melting out of ancient ice and even cryoconite. Cryoconite holes typically cover only 3-6% of the whole GrIS, whereas glacier algae appear to bloom wherever bare ice is present, therefore covering far greater areas.  In fact, a study reported an abundance of up to 85 thousand glacier algae cells per milliliter of melted surface ice collected in the Dark Zone.

Glacier algae have adopted many unique strategies for surviving in this extreme environment, yet one has elevated their global importance. Ice surfaces are subject to intense solar radiation, due to 24 hours of sunlight during the polar summer. As such, glacier algae have developed a dark pigmentation within their cells to help shield them from radiation. Because of this pigmentation and their high abundance in the Dark Zone, several studies have now concluded that pigmented algae have the greatest impact on ice surface darkening compared to any other nonalgal impurity, including black carbon or dust melting out of ancient ice. Yet, at present, algal influence on surface darkening, known as bioalbedo, is not being factored into melt rate models for the GrIS. 

You might also like: Deoxygenation: What To Expect From Our Future Oceans

Pigmented glacier algae, as seen under a microscope. (Source: Yallop et. al, 2012/Nature.com)

The GrIS has experienced a significant increase in net mass loss in the past two decades, increasing from 34 gigatonnes of ice per year during 1992 – 2001 to 215 gigatonnes of ice per year during 2002 – 2011, with surface ice accounting for nearly 68% of that increase since 2009.  As temperatures continue to rise in the Arctic, seasonal snow packs, which form during the winter and melt away in the spring, will retreat earlier, leading to an extended season of bare ice exposure. This will result in more surface ice melt and nutrient and liquid water availability, perfect growing conditions for glacier algae blooms. Furthermore, the burning of fossil fuels releases nutrients necessary for cell growth, such as nitrogen, into the atmosphere, which are transported to surface ice environments that are otherwise nutrient-limited.  This extra abundance of nutrients allows for microbial communities to spend less energy on producing nutrients and more energy on growth.  

It can therefore be expected that these blooms seen on the GrIS, and on glaciers and ice sheets throughout the cryosphere, will continue to escalate leading to further darkening of the sheet and increased melt rates, resulting in increased sea-level rising. 

Featured image by: Christine Zenino

The climate report warns of increasing sea-level rise as the polar ice caps continue to melt and says that as a result, intense storms, coastal flooding, and loss of marine life due to global warming are already inevitable. But the world still has time to avert even more severe consequences.

A new report from the Intergovernmental Panel on Climate Change (IPCC)  warns that extreme events caused by sea-level rise from melting ice caps – high tides, intense storms, and massive floods that used to occur once a century- will strike every year worldwide by 2050, no matter whether global emissions are curbed or not. 

The report, written by more than 100 climate and marine scientists from more than 36 countries, explores the links between oceans, glaciers, ice caps and the climate. It states that sea level rose globally by about 15 cm during the whole of the 20th century, and it is currently raising more than twice as fast, and accelerating over time. 

How does greenhouse gas emission affect sea level rise?

If greenhouse gas emissions are reduced significantly, preventing a 2C temperature increase, global average sea levels could still rise by 30 to 60 cm above current levels by 2100. If emissions keep climbing instead of falling, and it causes 2C or more temperature increase, sea levels could rise by one metre by the end of this century — ten times the rate in the 20th century. At this rate, the rise could exceed five metres by 2300.

The report warns that the world could lose many of its glaciers by the end of this century because of global heating. Small glaciers in Europe, eastern Africa, the tropical Andes, and Indonesia are expected to lose more than 80% of their current ice mass by 2100. “Many glaciers are projected to disappear regardless of future emissions,” the report says. “About 20 cm of sea-level rise from melting glaciers alone is likely in a 2C scenario. If emissions are drastically cut and warming is stabilised at 1.5C, glacier melt from the warming already locked in would contribute about 8.9 cm of sea-level rise.”

As glaciers continue to melt in Greenland and Antarctica, the sea-level rise is further accelerating. “In recent decades the rate of sea-level rise has accelerated, due to growing water inputs from ice sheets in Greenland and Antarctica, in addition to the contribution of meltwater from glaciers and the expansion of warmer sea waters,” says Valérie Masson-Delmotte, co-chair of a UN Intergovernmental Panel on Climate Change group that produced the report. “This new assessment has also revised upwards the projected contribution of the Antarctic ice sheet to sea-level rise by 2100 in the case of high emissions of greenhouse gases.”

You might also like: COP26 Postponed: What Does This Mean for the Climate Crisis?

Climate change is devastating the oceans and polar regions as never before, the report warns.

In the Himalayas, glaciers feeding ten rivers, including two prominent trans-boundary rivers in Asia — the Ganges and Yangtze, could shrink dramatically if emissions do not fall, hitting water supplies across the continent. Thawing permafrost in places like Alaska and Siberia could release vast quantities of greenhouse gases, potentially unleashing feedback loops driving faster warming.

The report projects that 20-90% of the world’s current coastal wetlands would disappear by 2100, depending on different sea-level scenarios. Since 1950, more than 50% of the world’s wetlands have already vanished.

Meanwhile, marine heatwaves are becoming more intense, devastating coral reefs — including much of Australia’s Great Barrier Reef. The heatwaves have grown more intense and doubled in frequency since 1982 making oceans hotter, more acidic, and less oxygenated. They would be 20 times more frequent in a 2C world, and if emissions push temperatures past that point, they would happen 50 times more often. 

The world still has time to avert the severe consequences of climate change by curbing global warming below 2C. “We will only be able to keep global warming to well below 2C above pre-industrial levels if we effect unprecedented transitions in all aspects of society, including energy, land and ecosystems, urban and infrastructure as well as industry,” says Debra Roberts, a co-chair of IPCC working group. “The ambitious climate policies and emissions reductions required to deliver the Paris Agreement will also protect the ocean, and ultimately sustain all life on Earth.”

Greenland is the world’s largest island with a vast body of ice sheet covering 1,710,000 sq km, roughly 80% of the surface. The climate here has been exceptionally stable in the past 10,000 years. But the Greenland ice sheet is now changing drastically.

Greenland ice sheet is a relic from the ice age, when gigantic glaciers covered vast stretches of the Northern Hemisphere. The ice in most places–Canada, the northeastern regions of the US, and Scandinavia–had melted away about 10,000 years ago. Although the Greenland ice sheet has persisted so far, it may not, anymore.

Authors of a new study published in the journal Proceedings of the National Academy of Sciences estimates that the Greenland ice sheet is now sloughing off an average of 286 billion tons of ice per year. Two decades ago, the annual average was just 50 billion. An analysis of satellite data reveals that the mass loss has increased sixfold since the 1980s.

Another study published last year reconstructed the changes in Greenland’s ice sheet over the past 350 years using ice cores and satellite data, and cataloged the history of variations in the ice sheet.

The research team found that melting in Greenland ice sheet started to pick up shortly after the dawn of the Industrial Revolution in the mid-1800s, when humans started burning coal, oil, and natural gas in huge quantities, sending tons of heat-trapping greenhouse gases into the atmosphere.

However, it’s only over the last 20 years that the melt rate has definitively increased beyond natural variability. One section of the ice sheet saw its melt intensity surge 575 percent over the last 20 years compared to pre-industrial times.

Sled dogs pull researchers from the Danish Meteorological Institute through meltwater in Greenland. Source: Steffen M Olsen/Twitter

Greenland gains some ice in the winter and loses some in the summer, but as the planet has warmed, the latter has outpaced the former. The ice sheet itself is also changing. The firn layer in the ice sheet, the boundary between snow and ice, is heating up and becoming denser. So water that would ordinarily trickle down through the snow and refreeze runs off the ice sheet instead.

The ice is also getting darker, as soot carried through the air and microorganisms like algae settle on the ice. Dark ice absorbs more solar energy and melts faster.

Besides global warming, a negative phase of the North Atlantic Oscillation (NAO)— a natural, irregular change in atmospheric pressure over the North Atlantic Ocean– also causes the rapid ice melt.   

What does it mean to you?

Although Greenland is located faraway at the northern end of the Atlantic Ocean, the sheer volume of ice melting into the ocean will have global repercussions affecting all of our lives.

Nasa reveals that if the Greenland ice sheet were to completely melt into the ocean, sea levels would rise by about 7 meters (23 feet) globally. The Earth’s rotation would slowdown lengthening the days. 

Greenland’s ice caps are currently the biggest single source of meltwater adding to the volume of the world’s oceans. They contribute about 20% of global sea-level rise, which is running at 4mm per year. All the melted ice has already contributed to more than 1.5 cm of global sea-level rise since 1972. Half of that increase came about in the last eight years alone. This pace is primed to double by the end of the century, according to the recent models used by the UN Intergovernmental Panel on Climate Change.

Rising water has already swallowed up at least eight low-lying islands in the Pacific Ocean. It also has increased coastal erosion. In Bangladesh and Thailand, coastal mangrove forests–important buffers against storms and tidal waves–are giving way to ocean water. Low-lying island nations, especially in equatorial regions, have been hardest hit. 

Vietnam is among the most vulnerable nations to global sea-level rise

A World Bank study found that if sea level were to rise by 1 metre, an area of 74,000 sq km in twelve countries–Brunei, Cambodia, China, Indonesia, North and South Korea, Malaysia, Myanmar, Papua New Guinea, Philippines, Thailand, and Vietnam–would be submerged permanently. Coastal communities in these countries will continue to face billion-dollar disaster recovery bills as flooding becomes more frequent and storms become more intense.  

Besides rising sea level, the relentless stream of meltwater threatens to disrupt oceanic currents stemming from the Gulf of Mexico that warm Europe’s coasts, contributing in no small measure to upkeeping the temperate climate north of the Mediterranean. Altering these currents, collectively known as the Atlantic Conveyor could lead to considerable changes in climate and rainfall patterns throughout the Northern Hemisphere. 

Ice sheets act as a protective cover over the land and ocean. They reflect the majority of the solar radiation back into space, keeping the planet cooler. Once they melt away, the excess heat would remain in the atmosphere causing a so-called feedback loop, which will warm the planet further. This temperature increase in air and ocean will create more frequent and intense coastal storms like hurricanes and typhoons in the Northern Hemisphere.  

Letting global temperatures get any higher could lead to irreversible mass loss of ice in Greenland. Cutting greenhouse gas emissions as aggressively as possible to limit the warming is the only solution. As the Intergovernmental Panel on Climate Change pointed out, limiting the temperature to 1.5C by 2050 would require an unprecedented global coordinated effort. 

 

 

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