Home Ice bergs Post offers thin evidence Antarctica is not losing ice

Post offers thin evidence Antarctica is not losing ice

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The statement

A post on Facebook claims Antarctica is not losing ice as a number of bases at the UK research station have already been destroyed by the accumulation of snow.

The July 1 post through Ken Ring, an astrological meteorologist from New Zealand, features a photo of the UK’s Halley VI Antarctic Research Station. Its caption states: “There have been five previous bases at Halley, all now covered in rising snow, giving (sic) the lie that the ice of Antarctica is disappearing.”

He goes on to say: “The truth about the snowfall in Antarctica is hidden from the world, lest the public (sic) learn that ‘global warming’ is nonsense.”

The post also predicts that Antarctica could experience some of its lowest temperatures on record this winter.

One article claims that global warming is “nonsense”, pointing to the accumulation of snow in Antarctica as evidence.

Analysis

While several British bases in Halley have been destroyed by the accumulation of snow, this fact is not related to the disappearance of the Antarctic ice or to climate change.

Several experts said AAP fact check the bases were built on top of the ice caps away from where the ice melts or breaks off, which covers them with ice and snow during regular accumulation. However, Antarctica is generally losing land ice.

The Halley base of the British Antarctic Survey (BAS) was established in 1956 and is used for research in atmospheric science, geology and glaciology. Since then there have been five bases – including the current Halley VI base – all built on the Brunt Ice Shelf. Four of them were eventually made uninhabitable.

The shelf records about 1.2 meters of snow per year, which forces the bases to be rebuilt periodically as they become covered in snow and crash, according to the BAS.

André Berger, a professor of Earth observation at the University of Leeds with expertise in polar and climate sciences, said FactCheck AAP that Antarctic bases like Halley only experienced snowfall when they were placed over the ice cap, where little melting or ice breaking occurred.

“Anything that is placed above the ice cap will be buried over time and eventually end up at the base or edge (by the movement of ice carrying older ice towards the edge) where it will melt. or will be released, “Professor Shepherd said in an email.

Ian simmonds, professor at the School of Earth Sciences at the University of Melbourne, agreed, stating FactCheck AAP in an email: “Precipitation is falling on the continent and that means that in most places above Antarctica, objects on the surface will eventually be buried. While this is true, it in itself has nothing to do with the argument that the continent is gaining in mass. “

For the claim that the disappearance of Antarctic ice is a “lie”, experts said there is a consensus backed by scientific evidence to show that Antarctica is losing ice.

Professor Shepherd described the post as misleading as it appeared to be based solely on Antarctic snowfall, which he said was only half the story.

“Antarctica receives around 2,098 billion tonnes of snow each year (1979-2008 average), but it also loses around 2,306 billion tonnes per year (2009-2017 average) due to the calving of icebergs on the shore and the melting ice at the base. he said.

“So it’s losing 208 billion tonnes of ice a year overall, which means it’s shrinking instead of growing.”

Professor Rob DeConto, a polar climate change expert at the University of Massachusetts, said Antarctica is losing ice “at a breakneck rate.”

“The rate of ice loss is accelerating (demonstrated by several data sources and with a high level of confidence). The rate of ice loss has tripled during the decade 2007-2017, compared to the previous decade, mainly in response to the change in ice sheet flow triggered by warm ocean waters in contact with the edge of the ice sheet, ”he said AAP fact check in an email.

The United States-based National Snow and Ice Data Center says the Antarctic Peninsula is experiencing ice loss as it has warmed by 2.5 degrees Celsius since 1950, while much of the West Antarctic Ice Cap also loses mass.

NASA satellite data indicates that the Antarctic ice sheet loses 151 billion tonnes of ice per year, the organization says. The ice cap is the biggest store frozen freshwater in the world.

Professor Simmonds identified that the term “Antarctic ice” can be defined by three main categories: the ice cap covering the land and bedrock of Antarctica; sea ​​ice, which floats on the ocean; and pack ice, permanent floating ice caps connected to the Antarctic landmass.

Of these, only sea ice levels have remained relatively stable, according to UK data Royal Society, the National Oceanic and Atmospheric Administration (NOAA) and Nasa. Professor Simmonds said sea ice levels in Antarctica rose until about 2015, but have since started to decline.

Experts have also disputed the claim that Antarctica may record some of its lowest temperatures this winter.

Professor Simmonds said parts of Antarctica have recently experienced unusually cold weather due to a Polar vortex, it’s part of the natural climate system.

“It is naive to choose an isolated event (in time and / or in space) to make a general statement about the whole climate system,” he said.

Likewise, Professor Chris Rapley, climatology and polar science expert at University College London and former director of British Antarctic Inquiry, Told FactCheck AAP that “a swallow does not make summer”.

“If there has been or is expected to be an extreme low, that does not invalidate a trend,” he said in an email.

A scientific article co-authored by Professor Simmonds details a global warming trend over the entire Antarctic continent from 1950 to 2020 (Figure 1a), while the The World Meteorological Organization recognized a new Antarctic temperature record of 18.3 ° C this month.

FactCheck AAP asked for Mr. Ring’s comment on the Facebook post but received no response.

Antarctic ice loss rate is accelerating, polar climate change expert told AAP FactCheck

The verdict

The destruction of the British Antarctic Survey’s Halley research stations by snowfall is not linked to global warming or the disappearance of Antarctic ice. Rather, anything placed on the Antarctic ice sheet will be buried by regular snowfall over time. Overall, Antarctica is losing ice, according to experts and various monitoring organizations.

False – Content that has no factual basis.

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