peninsula

Antarctic greening

November 6, 2024 By EarthWise Leave a Comment

The Antarctic Peninsula, like other polar regions, is warming faster than the rest of the world. Ocean heatwaves and ice loss are becoming more common and more severe.

New research by the universities of Exeter and Hertfordshire in the UK along with the British Antarctic Survey used satellite data to assess how much the Antarctic Peninsula has been greening in response to climate change. The Antarctic Peninsula is an 800-mile extension of Antarctica toward the southern tip of South America.

The study found that the area of vegetation cover across the Peninsula increased from less than one square kilometer in 1986 to almost 12 square kilometers in 2021. This greening trend accelerated by more than 30% in the period 2016-2021 relative to the entire 1986-2021 period.

An earlier study also showed that the rates of plant growth on the Antarctic Peninsula has increased dramatically in recent decades. The landscape is almost entirely dominated by snow, ice, and rock, with only a tiny fraction supporting plant life. The plants found on the Peninsula – mostly mosses – grow in some of the harshest conditions on earth. But that tiny fraction has greatly increased, showing that this isolated wilderness is being altered by climate change.

The sensitivity of the Antarctic Peninsula’s vegetation to the changing climate is evident and as warming continues, there could be fundamental changes to the biology and landscape of this unique and vulnerable region.

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Antarctic ‘greening’ at dramatic rate

Photo, posted June 2, 2018, courtesy of Murray Foubister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record Polar Ice Melting | Earth Wise

May 30, 2023 By EarthWise Leave a Comment

Sea levels are rising and ocean warming is responsible for the bulk of that rise. As water heats up, it expands, which drives up sea levels. But on top of that, global warming is melting the polar ice sheets, and that is leading to about a quarter of the world’s sea level rise. So far, polar melting has fueled about an inch of sea level rise, two-thirds from Greenland and one third from Antarctica. According to scientists, by the end of this century, melting polar ice caps could raise sea levels between 6 and 10 inches.

The seven worst years for polar ice sheet melting have occurred during the past decade. The worst year on record was 2019. The loss in 2019 was driven by an Arctic summer heatwave, which resulted in record melting from Greenland, amounting to nearly 500 billion tons melted that year. Antarctica lost 180 billion tons of ice that year, mostly due to melting glaciers and record melting from the Antarctic Peninsula.

Ice losses from Greenland and Antarctica can now be reliably measured by satellites in space. A team of researchers led by Northumbria University in the UK has combined 50 satellite surveys taken between 1992 and 2020.

They have found that the Earth’s polar ice sheets have lost over 8,000 billion tons of ice over that time period. That much ice corresponds to an ice cube roughly 12 miles high.

The satellite technology is now at the stage where the ice sheet status can be continuously updated. Such monitoring is critical to predict the future behavior of the ice sheets and provide risk warnings of the dangers that coastal communities around the world will face.

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Polar ice sheet melting records have toppled during the past decade

Photo, posted December 19, 2017, courtesy of Jasmine Nears via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Antarctic Ice Collapse | Earth Wise

March 2, 2022 By EarthWise Leave a Comment

In Antarctica, a huge chunk of the Larsen B Ice Shelf collapsed suddenly and spectacularly in January.

The Larsen Ice Shelf is located on the northeastern side of the Antarctic Peninsula on the Weddell Sea. It was formed over the course of more than 12,000 years. The Weddell Sea used to be a completely frozen body of water. The famous Ernest Shackleton expedition in 1915 was trapped in its ice. But the Antarctic Peninsula has been steadily warming in recent decades.

The Larsen A Ice shelf collapsed in 1995 and the 1,250-square-mile Larsen B Ice Shelf collapsed in 2002. After that event, a portion of the detached ice shelf refroze in 2011 and was attached to the Scar Inlet Ice Shelf. The refrozen ice was called the Larsen B embayment.

In January, the embayment broke apart, taking with it a portion of the Scar Inlet Ice Shelf. It disintegrated within a matter of days. The combined Larsen Ice Shelves – called A, B, C, and D – once extended along a 1000-mile stretch of the eastern Antarctic Peninsula. Since 1995, it has shrunk from 33,000 square miles to 26,000 square miles.

These ice shelves float on the ocean, so their loss does not actually increase global sea levels. However, the shelves act as dams that hold back glaciers located on the land behind them. The loss of Antarctic ice shelves dramatically increases the rate at which glaciers flow into the sea, and that does increase global sea levels.

Now that the sea ice from the Larsen B embayment is gone, it is likely that there will be additional inland ice losses from the newly exposed glaciers.

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Remnant of Antarctica’s Larsen B Ice Shelf Disintegrates

Photo, posted February 13, 2018, courtesy of NASA/Nathan Kurtz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Antarctica’s Hot Summer | Earth Wise

May 1, 2020 By EarthWise Leave a Comment

The Southern Hemisphere’s recent summer brought drought, heatwaves and bush-fires that ravaged Australia. At the same time, Antarctica experienced a summer of extreme weather.

In East Antarctica, the Casey research station in the Australian Antarctic Territory had its first heatwave event, recording extreme maximum and minimum temperatures over three consecutive days in January. Record high temperatures were also reported at bases on the Antarctic Peninsula.

The Casey station recorded a record high maximum temperature of 49 degrees Fahrenheit and a record overnight low of 36 degrees. In February, Brazilian scientists reported a high temperature of 69 degrees at Marambio, an all-time record for Antarctica.

Ecologists say that the hot summer would most likely lead to long-term disruption of local populations, communities, and the broader ecosystem. That disruption could be both positive and negative.

Most life in Antarctica exists in small ice-free oases and depends on melting snow and ice for a water supply. Melt water from the warming temperatures will lead to increased growth and reproduction of mosses, lichens, microbes and invertebrates.

However, excessive flooding can dislodge plants and alter the composition of communities of invertebrates and microbial mats. If the ice completely melts early in the season, then ecosystems will suffer drought for the rest of the season.

Extreme events often have impacts for years after the event. There will be long-term studies of the areas affected by the recent Antarctic heat wave. Such extreme events associated with global climate change are predicted to increase in frequency and impact, and even the most remote areas of the planet are not immune to them.

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Antarctica’s summer of extreme heat

Photo, posted January 30, 2014, courtesy of Andreas Kambanis via Flickr

Earth Wise is a production of WAMC Northeast Public Radio.

Cracking In The Antarctic

February 24, 2017 By EarthWise

A rapidly-growing crack in the fourth-largest ice shelf in Antarctica has scientists watching for it to break off entirely. By early February, the crack in the Larsen C ice shelf was more than 100 miles long and some parts of it were 2 miles wide. In the two-month period between December and February, the crack grew by 17 miles, a pace of about five football fields a day.