antarctic

Missing Antarctic Sea Ice | Earth Wise

August 30, 2023 By EarthWise Leave a Comment

It is summer here in the United States, but it is winter in Antarctica. Antarctic sea ice is water that forms and melts entirely in the ocean and it has a pattern of growth and reduction that has been monitored by satellites for the past 44 years. The area of sea ice that surrounds the continent of Antarctica is known as the sea ice ‘extent’ and it had been quite stable for much of those years.

In 2016, the sea ice extent began to decline. Since then, there have been several record summer lows with both the summers of 2021/22 and 2022/23 setting new minimum records.

This August, the deviation from all previous records intensified. This winter’s sea ice extent is over 900,000 square miles below the long-term average, an area about the size of Greenland or, for example, Texas and Alaska combined.

Climate models have long predicted that Antarctic sea ice would reduce as a result of global warming but the current change to sea-ice extent is so dramatic that it is difficult to explain. Sea ice extent is affected by multiple factors including the El Niño Southern Oscillation, the strength of the southern hemisphere jet stream, and regional low-pressure systems. The warming climate is certainly the overall force that is changing Antarctic sea ice extent over time.

Antarctic sea ice extent is important because it covers a vast area of the dark Southern Sea with a bright white surface that reflects the sun’s energy back into space, helping to reduce temperatures at the pole and protecting glaciers and polar ice sheets.

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The mystery of the missing Antarctic sea ice

Photo, posted November 7, 2016, courtesy of Rob Oo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Arctic Communities And Permafrost Thaw | Earth Wise

December 16, 2021 By EarthWise Leave a Comment

Permafrost is frozen soil, rock or sediment that can be as much as a few thousand feet thick. To qualify as permafrost , the material has to have been at or below the freezing point of water for two or more years. Most of it is located in high latitudes in the Arctic and Antarctic regions. Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost contains enormous amounts of carbon in the form of frozen soil that includes remnants of plants and animals, in some cases that have been there for more than 20,000 years.

The Arctic region has been warming faster than any place else on earth and thawing permafrost is already unleashing methane and carbon dioxide to the atmosphere, adding to the global temperature rise.

Apart from the impact on the global climate, thawing permafrost is making the ground unstable and is causing serious problems for local communities.

Recent research using satellite observations provides an overview of the Arctic to identify communities and infrastructure that will be at risk over the next 30 years.

Using high-resolution data from the Copernicus Sentinel satellite missions along with ground-based data going back to 1997, researchers modeled the permafrost ground temperature trends and extrapolated them out to 2050. The results were that 55% of the infrastructure currently located on permafrost and within 60 miles of the Arctic coastline – infrastructure on which many communities rely – is likely to be affected.

Most human activity in the Arctic takes place along permafrost coasts. Permafrost thaw is exposing these coasts to rapid change that threatens biodiversity and puts pressure on communities.

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Satellites pinpoint communities at risk of permafrost thaw

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

July Was A Scorcher | Earth Wise

September 2, 2021 By EarthWise Leave a Comment

July 2021 has the unfortunate distinction as being the world’s hottest month ever recorded according to global data from the National Oceanic and Atmospheric Administration. July is typically the warmest month of the year, but this July was the warmest month of any year on record.

The combined global land and ocean surface temperature was 62.07 degrees Fahrenheit, which is 1.67 degrees above the 20th century average. This was the highest monthly average since records began 142 years ago. It broke the previous record set in July 2016 and tied in 2019 and 2020.

The Northern Hemisphere was 2.77 degrees above average. Asia had its hottest July on record. Europe had its second hottest July on record. Places like Africa, Australia, and New Zealand all had top-ten warmest Julys.

Other aspects of the changing climate included the observation that Arctic sea ice coverage for July was the fourth-smallest in the 43-year record. Interestingly, Antarctic sea ice extent was actually above average in July. Global tropic cyclone activity this year so far is above normal for the number of named storms. In the Atlantic basin, the formation of the storm Elsa on July 1 was the earliest date for a 5th named storm.

It remains very likely that 2021 will rank among the 10 hottest years on record. Extreme heat is a reflection on the long-term climate changes that were outlined recently in a major report released by the Intergovernmental Panel on Climate Change. These latest global observations add to the disturbing and disruptive path that the changing climate has set for the world.

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It’s official: July was Earth’s hottest month on record

Photo, posted July 15, 2021, courtesy of Lori Iverson/National Interagency Fire Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Greenland Becoming Darker | Earth Wise

July 5, 2021 By EarthWise Leave a Comment

According to research published by Dartmouth University, a weather pattern that pushes snowfall away from parts of Greenland’s ice sheet is causing the continent to become darker and warmer.

Reducing the amount of fresh, lighter-colored snow exposes older, darker snow on the surface of Greenland’s ice sheets. Fresh snow is the brightest and whitest. The reflectivity of snow decreases fairly quickly as it ages. This decrease in albedo – or reflectivity – allows the ice sheet to absorb more heat and therefore melt more quickly.

The research attributes the decrease in snowfall in Greenland to a phenomenon called atmospheric blocking in which persistent high-pressure systems hover over the ice sheet for up to weeks at a time. Such systems have increased over Greenland since the mid-1990s. They push snowstorms to the north, hold warmer air over Western Greenland, and reduce light-blocking cloud cover.

All of this contributes to Greenland melting faster and faster. According to research cited in the study, the Greenland ice sheet has warmed by nearly 5 degrees Fahrenheit since 1982. Overall, Greenland is experiencing the greatest melt and runoff rates in the last 450 years, at the minimum, and quite likely the greatest rates in the last 7,000 years.

The Greenland ice sheet is the second largest ice body in the world, after the Antarctic ice sheet. It is 1,800 miles long and about 700 miles wide at its greatest width. Its thickness is between 1.2 and 1.9 miles. If the entire sheet were to melt, it would lead to a global sea level rise of 24 feet. So, the darkening of Greenland is a source of great concern.

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Greenland Becoming Darker, Warmer as Snow Changes

Photo, posted April 3, 2012, courtesy of Francesco Paroni Sterbini via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Accelerating Global Glacier Loss | Earth Wise

June 10, 2021 By EarthWise Leave a Comment

Glaciers represent the snows of centuries compressed over time to form flowing rivers of ice. Glaciers always change, accumulating snow in the winter and losing ice to melting in the summer. But in recent times, the melting has been outpacing the accumulation.

Glaciers are a sensitive indicator of climate change. They have been melting at a high rate since the mid-20th century – regardless of altitude or latitude. But up until recently, the full extent of glacial ice loss has only been partially measured and understood.

Now, according to new research led by scientists from ETH Zurich in Switzerland and the University of Toulouse in France, nearly all the world’s glaciers are becoming thinner and losing mass. And the changes are accelerating. The study, which is the most comprehensive and accurate of its kind to date, is the first to include all the world’s glaciers – around 220,000 in total – excluding the Greenland and Antarctic ice sheets. The research team’s findings were recently published in the journal Nature.

Between 2000 and 2019, the world’s glaciers lost an average of more than 294 billion tons of ice per year. Between 2000 and 2004, glaciers lost an average of about 250 billion tons of ice each year. But between 2015 and 2019, ice mass loss jumped up to an average of approximately 328 billion tons annually.

Glacial melt is responsible for 21% of the observed sea level rise during this two decade time period studied.

This research is just another reminder of how we need to act urgently if we want to prevent the worst-case climate change scenario from becoming a reality.

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Global glacier retreat has accelerated

Photo, posted September 17, 2015, courtesy of Richard Whitaker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Replacing Plastic Tableware | Earth Wise

December 30, 2020 By EarthWise Leave a Comment

Plastics have been described as the “ubiquitous workhorse material of the modern economy.” But their versatility, pliability, and durability comes at a heavy price to the environment. Plastic pollution is quite literally everywhere. Plastic debris and microplastic particles can be found in every corner of the globe, including the Arctic and Antarctic.

The scourge of plastic pollution is driving scientists to create ecologically-friendly alternatives. According to a paper recently published in the journal Matter, scientists have developed “green” tableware made from sugarcane and bamboo that doesn’t sacrifice on convenience or functionality. This eco-friendly tableware could serve as a permanent replacement for plastic cups and other disposable plastic containers.

Traditional plastic polymers, a product of petroleum, can take as long as 1,000 years to decompose in landfills. The new material only takes 60 days to break down.

To create this material, scientists used bamboo and bagasse, also known as sugarcane pulp. Bagasse is one of the largest food-industry waste products. The researchers wound the fibers together to form a mechanically stable and biodegradable material. They added an alkyl ketene dimer, an eco-friendly chemical, to increase the oil and water resistance of the material. The green material is durable enough to hold liquids like hot coffee and hot greasy foods like pizza.

There’s another advantage: the green material’s manufacturing process emits 97% less CO2 than the process to make commercial plastic containers. The next step is to lower the manufacturing cost. While the cost of cups made from the green material is $2,333 per ton, traditional cups made from plastic are still slightly cheaper at $2,177 per ton.

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This tableware made from sugarcane and bamboo breaks down in 60 days

Photo, posted May 19, 2013, courtesy of Henry Burrows via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Return Of The Blue Whales | Earth Wise

December 21, 2020 By EarthWise Leave a Comment

An international research team has revealed that critically endangered Antarctic blue whales have returned to the sub-Antarctic island of South Georgia, 50 years after whaling just about wiped them out. Other recent research has found that humpback whales are also returning to the region.

Blue whales were commonplace off South Georgia before 20th century industrial whaling taking place between 1904 and 1971 killed over 42,000 of them there. Most of that number were killed before the mid-1930s. As a result, blue whales essentially vanished from the region. Whale survey ships sighted only a single blue whale between 1998 and 2018.

But things have changed in recent years. A survey this past February resulted in 58 blue whale sightings and numerous acoustic detections. Although commercial whaling was banned in the area in the 1960s, it has taken a long time for the whales to make a comeback.

Researchers are not sure why blue whales have taken so long to return to the area. It may be that so many were killed over the years that the remaining population had little or no cultural memory of South Georgia Island as a foraging ground, and that it is only now being rediscovered.

In total, 41 individual blue whales have been photo-identified from South Georgia over the past 10 years, although none of those matched the 517 whales in the current Antarctic blue whale photographic catalogue. Dedicated whale surveys are difficult in a region known for its harsh weather and inaccessibility but are crucial to the future management of South Georgia’s seas. In any case, researchers see the recent sightings as a very positive step forward for conservation of the Antarctic blue whale.

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Blue whales return to South Georgia after near extinction

Photo, posted September 7, 2007, courtesy of the NOAA Office of National Marine Sanctuaries via Flickr. Photo credit: NOAA.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record Antarctic Temperature | Earth Wise

March 5, 2020 By EarthWise Leave a Comment

It is still early in the year, but extreme weather events are already piling up. January was the warmest month on record globally and there have been many records shattered in Europe and Asia. A number of places in Eastern Europe, including parts of Russia, have seen temperatures 12 to 13 degrees above average.

While the warming of the Arctic has been in the news with increasing frequency, the Antarctic is also seeing rising temperatures and is one of the fastest-warming regions in the world.

On February 6th, Esperanza Base along Antarctica’s Trinity Peninsula measured a temperature of 65 degrees Fahrenheit, which is the highest temperature ever recorded on that continent. This rather balmy temperature narrowly beat out the previous record of 63.5 degrees, which occurred in March of 2015.

This one-time reading is certainly anomalous, and scientists say it is associated with a ridge of high pressure that was lingering over the region for several days. Local wind conditions led to additional warming.

However, the conditions leading to record-breaking high temperatures are not one-time anomalous events. Over the past 50 years, temperatures in the Antarctic have surged by an extraordinary 5 degrees in response to the Earth’s rapidly warming climate. A rise of five degrees in day-to-day weather is no big deal. A five-degree rise in a region’s average temperature is enormous.

About 87% of the glaciers along the west coast of Antarctica’s Trinity Peninsula have retreated over that 50-year period, most of which doing so during just the past 12 years.

Some researchers claim that the new temperature record is an extreme event that doesn’t tell us anything about the changing climate. Many others are convinced that there will be many more high temperature records to follow.

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Antarctica just hit 65 degrees, its warmest temperature ever recorded

Photo, posted February 24, 2019, courtesy of Mike via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Another Hot November

January 3, 2020 By EarthWise Leave a Comment

This past fall saw yet more of the high temperatures the world has been experiencing in recent times. Both the season (September through November) and the year to date were the second hottest in recorded history. November itself was the second-hottest November in the 140-year global climate record.

The high temperatures were felt at both ends of the world. Sea ice coverage across both the Arctic and Antarctic oceans fell to near-record lows in November. Arctic sea ice coverage was nearly 13% below the 1981-2010 average, while Antarctic coverage was 6.35% below average.

The average global land and ocean surface temperature for November was 1.66 degrees Fahrenheit above the 20^th century average. The year-to-date global temperature was 1.69 degrees Fahrenheit above the 20^th century average. These numbers correspond to almost a 1-degree Celsius increase, which should be compared with the Paris Climate Accord goal of keeping that increase to no more than 1.5 degrees.

November was the hottest November on record for South America, Africa, and the Hawaiian Islands. The Caribbean had its second-hottest November, and Europe had its seventh hottest on record.

The world’s average sea surface temperature ranked second warmest for the year to date and was only 0.05 degrees cooler than the all-time record.

The National Oceanic and Atmospheric Administration issues monthly global climate reports and for quite some time, these reports seem to all be the same. Another new record for heat or at least another near record. We have to expect that this trend will continue at least until the world starts making progress in dealing with its root cause.

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November 2019 was 2nd hottest on record for the planet

Photo, posted July 20, 2016, courtesy of Salehin Chowdhury via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The March Of The Penguins Toward Extinction

November 28, 2019 By EarthWise Leave a Comment

According to a new study from the Woods Hole Oceanographic Institution, the warming climate may render emperor penguins extinct by the end of this century. The study, which was part of an international collaboration between scientists, finds that emperor penguins will likely experience an 86% decline by 2100 if the global climate continues to warm at the current rate. At that point, it would be very unlikely for them to recover, according to the study’s lead author.

The research was funded by the National Science Foundation and recently published in the journal Global Change Biology.

The fate of emperor penguins is largely tied to the fate of sea ice. The penguins use sea ice as a place for breeding, feeding, and molting. They look for very specific conditions of sea ice – it must be locked in to the Antarctic shoreline but also close enough to open seawater to give them access to food. The study predicts that this sea ice will gradually disappear, depriving the birds of their habitat, food sources, and ability to raise their young.

The researchers combined two existing computer models to study three different climate change scenarios. If the average global temperature increases by only 1.5 degrees Celsius, the study found that only 5% of sea ice would be lost by 2100, resulting in a 19% drop in penguin colonies. If the planet warms by 2 degrees Celsius, the sea ice loss nearly triples and more than a third of penguin colonies disappear. The ‘business as usual’ scenario where the planet continues to warm at the current rate will ensure a near complete loss of emperor penguin colonies by 2100.

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Unless warming is slowed, emperor penguins will be marching towards extinction

Photo, posted January 15, 2011, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Degraded Permafrost In The Arctic

July 11, 2019 By EarthWise Leave a Comment

Permafrost is defined as rock or soil that has been at or below the freezing point of water for two or more years. Most of it is located in high latitudes in and around the Arctic and Antarctic regions. Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.

Permafrost can contain many different materials including bedrock, sediment, organic matter, water and ice. Because of the presence of organic matter, permafrost is potentially the source of significant methane emissions if it thaws and the trapped biomass begins to rot.

A recent study looked at the results of 30 years of aerial surveys and extensive ground mapping of an area of Canada’s high Arctic polar desert known as the Eureka Sound Lowlands. This area has an extremely cold climate and the permafrost there is over 1/3 of a mile thick. It has long been assumed that this landscape was stable.

Research led by McGill University in Montreal has found that this is not the case. The increases in summer air temperatures seen in recent years are initiating widespread changes in the landscape.

A particular landform known as a retrogressive thaw slump that forms when ice within permafrost melts and the land slips down is widely occurring in the area. The absence of vegetation and layers of organic soil in these polar deserts make permafrost in the area particularly vulnerable to increases in summer air temperatures.

The research indicates that despite the cold polar desert conditions that characterize much of the high Arctic, the interaction between ice-rich permafrost systems and climate factors is complex and the links between global warming and permafrost degradation are not well understood.

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Widespread permafrost degradation seen in high Arctic terrain

Photo, posted August 11, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rapid Antarctic Melting

June 28, 2019 By EarthWise 1 Comment

The Ross Ice Shelf in Antarctica is the world’s largest ice shelf, covering an area roughly the size of France. Scientists have spent several years building up a record of how the northwest sector of the enormous ice shelf interacts with the ocean beneath it. Their results show that the ice is melting much more rapidly than previously thought because of in-flowing warm water.

In general, the stability of ice shelves is thought to be mostly influenced by their exposure to warm deep ocean water. But the new research has found that surface water heated by the sun also plays a crucial role in melting ice shelves.

The interactions between ice and ocean water that occur hundreds of meters below the surface of ice shelves have a direct impact on long-term sea level. The Ross Ice Shelf stabilizes the West Antarctic ice sheet by blocking the ice that flows into it from some of the world’s largest glaciers.

When ice shelves collapse, the glaciers that feed them can speed up by a factor of two or three. None of the collapsing shelves in the past have come anywhere close to the size of the Ross Ice Shelf, which is more than 100 times bigger.

The new study by New Zealand’s National Institute of Water and Atmospheric Research showed that sun-heated surface water flowing into the cavity under the ice shelf near Ross Islands caused melt rates to nearly triple during the summer months. This indicates that the loss of sea ice resulting from climate change is likely to increase melt rates in the future. While the Ross Ice Shelf is still considered to be relatively stable, the new findings show that it may be more vulnerable than previously thought.

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Rapid melting of the world’s largest ice shelf linked to solar heat in the ocean

Photo, posted February 15, 2009, courtesy of Alan Light via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Melting Ice In Greenland

January 18, 2019 By EarthWise Leave a Comment

The Greenland ice sheet is the second largest ice body in the world after the Antarctic ice sheet. It covers over 660,000 square miles, more than twice the size of the state of Texas. But it is melting.

According to a new study published in the journal Nature, the Greenland ice sheet is melting faster today than at any point in the last 350 years. A team of U.S. and European researchers analyzed more than three centuries of melt patterns in ice cores from western Greenland. They then linked this historical data to modern observations of melting and runoff across the entire ice sheet.

According to the researchers, from an historical perspective, today’smelt rates are off the charts. There is a 50% increase in total ice sheet melt water runoff since the start of the industrial era and a 30% increase since the 20th century alone.

Over the last 20 years, melt intensity has increased 250 to 575 percent compared to pre-industrial melt rates. The period from 2004-2013, the most recent decade analyzed, experienced a more sustained and greater magnitude of melt than in any previous 10-year period in the 350-year record.

The Greenland ice sheet is the largest single contributor to global sea level rise. It is adding 72 cubic miles of meltwater to the world’s oceans every year.

The melting of the Greenland ice sheet is accelerating which is a frightening prospect. If the sheet were to melt in its entirety, global sea levels would rise by 23 feet. The world needs to do whatever it can to keep that doomsday scenario from happening.

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Greenland Ice Sheet Melting At Fastest Rate in 350 Years

Photo, posted September 8, 2014, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Japan And Whaling

January 10, 2019 By EarthWise Leave a Comment

The commercial hunting of whales nearly drove the giant mammals to extinction. By the 1960s, as hunting technologies improved and ships began to resemble floating factories, it became clear that whaling could not continue unchecked.

But despite all this, commercial whaling was never actually banned. Instead, in 1986, members of the International Whaling Committee (IWC) agreed to a whaling moratorium in order to allow whale stocks to recover. Pro-whaling nations like Japan, Iceland, and Norway expected the moratorium to be temporary until the whales stocks recovered, and a consensus on catch quotas could be established. But the temporary moratorium became a quasi-permanent ban, much to the delight of conservationists and to the dismay of whaling nations.

As a result, Japan recently announced it is leaving the international agreement and plans to resume commercial whaling. The agreement though never really stopped Japanese whaling in the first place, because it allowed the country to kill whales for scientific research. Japan has had an annual Antarctic catch quota of 333 minke whales, producing notoriously little in terms of whale science while producing lots of whale meat. As part of its withdrawal from the IWC, Japan will cease its Antarctic hunts and limit whalers to its own waters. Commercial Japanese whaling will resume in July.

Once popular in Japan, whale meat consumption has plummeted, falling 98% between 1962 and 2016. The industry employs fewer than 1,000 people and is dependent on government subsidies.

Many governments and conservationist groups condemned Japan’s withdrawal, declaring the move out of step with the international community. They argue that, rather than hunting whales, urgent action is needed to conserve marine ecosystems.

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