Global Warming

NASA Satellite Spots Mile-Long Iceberg Breaking Off of Antarctic Glacier

A massive, 1-mile-long (1.6 kilometers) chunk of ice has broken off Antarctica’s fast-changing Pine Island Glacier, and NASA satellites captured the dramatic event as the icy surface cracked and ripped apart.

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Pine island glacier

Global Warming

Global warming is responsible for melting mountain glaciers: study

Since glaciers respond slowly to climate change and are susceptible to yearly weather changes, there has been some debate in the scientific community about whether climate change was entirely to blame for their ice melt.

For instance, the last report from the UN Intergovernmental Panel on Climate Change concluded only that it was “likely” that a “substantial” part of mountain glacier retreat is due to human-induced climate change.

The latest study in Nature Geoscience uses statistical techniques to analyze 37 mountain glaciers around the world.

For most of them the observed retreat is more than 99 percent likely due to climate change, said the report, meaning scientists are “virtually certain” of this cause-and-effect over the past century.

“Because of their decades-long response times, we found that glaciers are actually among the purest signals of climate change,” said co-author Gerard Roe, a University of Washington professor of Earth and Space Sciences.

For instance, researchers determined that the Hintereisferner Glacier in Austria has retreated 1.75 miles (2.8 kilometres) since 1880, and that climate change is extremely likely to be responsible, with the probability that the changes are natural variations being less than 0.001 percent, or one in 100,000.

For the well-known Franz Josef Glacier in New Zealand, there is a less than one percent chance that natural variations could explain the overall two-mile retreat in the last 130 years, it said.

Among the glaciers with the least certainty that global warming is to blame were Rabots Glacier in northern Sweden and South Cascade Glacier in the US northwestern state of Washington.

For those the probability that their retreats might be due to natural variability in weather patterns ranged between six and 11 percent.

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Global Warming

Tibetan glaciers are being destroyed by global warming

Scientists have issued a grave warning about the future of glaciers in western Tibet after nine yak herders were killed in an avalanche. They say global warming is destabilising the dense ice formations that they once thought were immune from rising temperatures.

Meltwater seeping under glaciers of the Tibetan Plateau triggered a deadly avalanche this year, sweeping the nomadic yak herders to their deaths. Two months later a neighbouring glacier in the same mountain range without warning gave way.

Researchers have now found the meltwater in the first avalanche acted as a lubricant between the ground and the ice allowing it to slide down the mountain at speed with devastating effects.

Glaciers in Western Tibet

Half the world’s species failing to cope with global warming

Nearly half the species on the planet are failing to cope with global warming the world has already experienced, according to an alarming new study that suggests the sixth mass extinction of animal life in the Earth’s history could take place in as little as 50 years.

A leading evolutionary biologist, Professor John Wiens, found that 47 per cent of nearly 1,000 species had suffered local extinctions linked to climate change with populations absent from areas where they had been found before.

Professor Wiens, who is editor of the Quarterly Review of Biology and a winner of the American Society of Naturalists’ Presidential Award, said the implications for the future were serious because his review showed plants and animals were struggling to deal with the relatively small amount of global warming experienced to date.

So far the world has warmed by about 1C above pre-industrial levels, but it is expected to hit between 2.6 and 4.8C by 2100 if nothing is done to reduce greenhouse gases.

Another problem facing life on Earth is the election of climate science denier Donald Trump as US president.

Professor Wiens, of Arizona University, described this as a “global disaster” and, when asked what he would say to the President-elect if he met him, he joked grimly: “Kill yourself immediately.”

In his study, published in the journal PLOS Biology, the scientist examined academic papers about 976 different species from all over the world that had been studied at least twice, once about 50 years ago and again within the last 10 years.

“In almost half the species looked at, there have been local extinctions already,” he said.

“What it shows is species cannot change fast enough to keep up with a small change in climate. That’s the big implication – even a small change in temperature and they cannot handle it.”

The study looked at 716 different kinds of animals and 260 plants from Asia, Europe, North and South America, and elsewhere.

Local extinctions were found to have occurred among 47.1 per cent of species at the “warm edge” of their traditional range, as it became too hot for them. There were few areas of the planet that were unaffected.

Global Warming

New Zealand losing glaciers due to global warming

New Zealand, a country famous for its tourist attractions and magnificent sceneries, is losing its glaciers due to global warming, a study indicates. Fox and Franz Josef, two stunning glaciers that run from the mountains to a temperate rain forest, are at risk. The ice is melting so fast that it has become too dangerous for tourists to hike onto the glaciers, bringing an end to a tradition dating back to a century. The warm temperatures due to global warming are responsible for the glaciers melting, according to researchers.

Scientists feel that the melting of Fox and Franz Josef is one of the examples how global warming is adversely affecting the environment. Helicopters are now the only means of getting to the glaciers, which till last year could be climbed

A paper published in 2014 in the Global and Planetary Change said that each of the two glaciers had melted by up to 3 kilometres in length since the 1800s, reducing them in height by about 20 percent. The authors also said that due to global warming, the ice has been melting at a rate never recorded before.

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Global Warming

How Much Ice Can Antarctica Afford to Lose?

Over the past 20 years, ice shelves in Antarctica that normally support the rest of the continent’s glaciers have been shrinking, and some have disappeared entirely. How much more ice can disintegrate before Antarctic glaciers start freely tumbling into the ocean?

A recent study led by researchers at the Friedrich-Alexander-Universität, in Germany, has mapped out which Antarctic ice shelves are buttressing the most ice and which are more “passive” and thus can stand to lose a large area without any immediate effect on the rest of the ice shelf.

Ice shelves are slabs of ice several hundred meters thick that extend from the edges of the mainland and float on the surface of the sea. They are firmly linked to glaciers and ice streams in mainland Antarctica, which slowly push the floating ice farther seaward, according to the researchers. When the seaward fronts of these ice shelves break off, they form new icebergs and the loss of ice is naturally replenished by the glacier ice from the mainland flowing in.

Some of the ice shelves, however, also push back on the glaciers, providing resistance and reducing the speed at which the glaciers flow into the ocean, said lead study author Johannes Fürst, a research assistant at the Institute of Geography at the Friedrich-Alexander-Universität.

“Ice shelves restrain the outflow from upstream like a plug in a bathtub,” Fürst told Live Science. “If you take the plug out, the water runs out, except this is frozen water and if you take out the ice shelves its flow will accelerate out into the ocean and eventually raise sea levels.”

In 1995, Antarctica’s Larsen A ice shelf collapsed, removing ice cover from an area equivalent to the size of Berlin, according to Fürst. Seven years later, the much larger Larsen B ice shelf also broke apart. While the disintegration of the two shelves did not have an immediate effect on sea levels, the ice loss resulted in upstream glaciers accelerating by up to eight times their normal flow, according to the researchers.

Overall, the researchers found that 13 percent of the continent’s ice shelf area can be classified as passive — an area about twice the size of Spain. This includes the Larsen C ice shelf in the Weddell Sea, which the researchers found is almost entirely a passive ice shelf.

Ice shelves in the Amundsen and Bellingshausen seas, however, are the most susceptible to further ice loss, according to the research findings. They are made up of 7 percent and 5 percent passive ice, respectively, the researchers found.

Global Warming

Record Melt Occurring in Greenland Glaciers

Greenland’s glaciers are retreating under the influence of climate change at least twice as fast as any other time in the past 9,500 years, according to new research.

Scientists from Columbia University’s Earth Institute made the discovery after examining sediment cores from the bottom of a glacier-fed lake in southeastern Greenland.

They then compared the findings to analyses of similar cores from Iceland and Canada’s Baffin Island, and with recent satellite observations.

They found that before the 20th century, the fastest rate of glacier retreat occurred about 8,500 years ago, when the Earth’s position relative to the sun resulted in more summer sunlight warming the Arctic.

Despite less direct summer sunlight in recent years, Greenland’s glaciers have melted at an unprecedented rate because of warming brought on by higher greenhouse gas concentrations.

“If we compare the rate that these glaciers have retreated in the last hundred years to the rate that they retreated when they disappeared between 8,000 and 7,000 years ago, we see the rate of retreat in the last 100 years was about twice what it was under this naturally forced disappearance,” said study co-author William D’Andrea.

The study also provided new evidence for just how sensitive glaciers are to temperature, showing that they responded to past abrupt cooling and warming periods, some of which might have lasted only decades.

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Global Warming

Central Asian glaciers shrinking fast

Central Asian glaciers have melted at four times the global average since the early 1960s, shedding 27 per cent of their mass, according to a study released today.

By 2050, warmer temperatures driven by climate change could wipe out half the remaining glacier ice in the Tien Shan mountain range, reported the study, published in Nature Geoscience.

At stake is a critical source of water for people in Kazakhstan, Kyrgyzstan and Uzbekistan, as well as a section of northwest China.

“Glaciers are actually huge water stores. They can balance water between wet and dry years,” said co-author Doris Duethmann, a researcher at the GFZ German Research Centre for Geosciences in Potsdam.

Tien Shan glaciers have lost an average of 5.4 billion tonnes of ice per year since the 1960s, totalling some 3,000 square kilometres (1,158 square miles).

The rate at which the glaciers shrank greatly accelerated in the 1970s and 1980s.

Climate models point to higher summer temperatures in coming decades along the 2,500 kilometres of the Tien Shan range, thus making the glaciers even more vulnerable, the study said.

Global Warming

Peru’s Glacial Melt-Off Reaches 40 Percent

Glaciers near the southern South American country of Peru have shrunk by 40 percent in the past four decades, which has created a number of high-altitude lakes.

Climate change is the cause for the melt-off, which has spawned nearly 1,000 new high-altitude lakes since 1980, the Peruvian government said Wednesday.

The glaciers in Peru are small compared to those found in the north and south poles, and are at a greater risk of disappearing. In addition, 70 percent of the world’s tropical glaciers are found in Peru, and they are extremely sensitive to the warming temperatures associated with climate change.

In the coming years, 90 percent of the 2,679 glaciers could disappear, the country’s water authority said, updating its report of glacier inventory that was last issued in the 1970s.

Those at greater risk of melting away are smaller than 1-square-kilometre, and spread over 19 snow-capped mountain ranges of the Andes.

Officials said 996 lakes have emerged in the Andes since the last count in 1980, which increases the total to 8,355.

They are the majority source of the country’s drinking water.

Global Warming

Global warming is behind disturbing retreat of Peruvian glaciers: Study

Stretching across a vast volcanic plain in Peru, the Quelccaya Ice Cap is the tropics’ largest sheet of ice—for now. Climate shifts are taking their toll, according to scientists who note that the glacier has been not only losing ice over the last few decades but doing so over an accelerating rate. And following a study recently published in the journal Geology, many scientists are now more certain than ever that the ice loss is due to rising temperatures.

It may hardly sound like a surprise that a glacier’s retreat would be due to warming climate, but researchers monitoring the Quelccaya and other shrinking glaciers in the tropics have had their honest doubts. Some have hitherto suggested that decreased snowfall might be the culprit, for example.

The Geology study, however, identifies temperature as the first and foremost driving factor. Led by Justin Stroup, a Dartmouth College doctoral candidate in Earth sciences; and Meredith Kelly, a Dartmouth assistant professor of Earth sciences; the study’s research team compiled extensive data on the Qori Kalis, a valley glacier that is a major outlet for the Quelccaya Ice Cap, and constructed a timeline of this glacier’s waxing and waning across the past 500 years.

Next, they compared the glacier’s movements to records of ice accumulation on the Quelccaya plateau. Long cylinders of ice previously drilled and extracted by Lonnie Thompson, an Ohio State University geologist, were the source of these records.

If snowfall is the main factor behind the ice gain or loss, then the valley glacier should gain ice when more ice accumulates on the Quelccaya, and lose ice when the Quelccaya’s ice accumulation hits a dry spell. Stroup, Kelly, and their team found the opposite: The valley glacier lost ice during some periods of high accumulation and gained ice during some periods when the Quelccaya’s ice accumulation was low.

Temperature, not snowfall, is evidently the chief driver, according to the researchers. They have the backing of Thompson, who has long argued that the glacier could be thought of as a large thermometer.

Their conclusion is a troubling one as far as this glacier is concerned. Thompson’s analyses indicate that in the last 25 years, the glacier has lost a volume of ice that took 1,600 years to build up.

This glacier is no anomaly, by the way. Land ice is melting across the tropics and throughout the planet, and showing marked increases in the rate of ice loss during the last three decades. Quelccaya could be a microcosm of melting trends throughout the globe, according to the researchers, who plan to conduct further studies of more glaciers elsewhere on the globe.

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Environment

Many of the world’s glaciers and ice sheets are retreating in the face of global warming, but a few are stable or growing — including glaciers in the western Himalaya Mountains, according to a new report. The mountains in the region form the headwaters of several major river systems — including the Ganges, Mekong, Yangtze, and Yellow rivers — which serve as sources of drinking water and irrigation supplies for about 1.5 billion people.

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The US National Weather Service in Los Angeles released two notices of triple-digit record-breaking temperatures in Long Beach over the weekend. On Friday, a high of 104 degrees was recorded, breaking the old record of 96 set in 1979.

Global Warming

A  recent study suggests that Greenland’s glaciers may be melting at a slower rate leading to a slower rise in sea water levels. The study extended over ten years ending in 2011. A caveat is that the full effects of global warming may not have reached Greenland’s  northern glaciers yet.