View of an iceberg on Half Moon island, Antarctica on November 9, 2019 ( AFP / Johan Ordonez)

Misleading posts claim record Antarctica cold disproves global warming

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Social media posts cite record cold temperatures in Antarctica as evidence that global warming is exaggerated or non-existent. But glaciologists and climate scientists say the cold weather does not mean climate change is not occurring, and that global warming is resulting in overall higher temperatures and melting ice in Antarctica.

"HOW DOES THIS GO TOGETHER WITH A GLOBAL WARMING SCARE?" says an October 15, 2021 Facebook post asks, sharing a link to an article about the record low temperatures.

A screenshot of a Facebook post taken on October 22, 2021

"COLDEST ANTARCTICA TEMPERATURES ON RECORD. SO MUCH FOR GLOBAL WARMING THEORY," says an earlier post sharing a link to an article on the topic, while another says: "Thats why they changed it from Global Warming to Climate Change....kick rocks Al Gore."

On October 5, the US-based National Snow and Ice Data Center (NSIDC) reported that Antarctica's 2021 winter was the second coldest winter (June, July and August) on record, "behind only 2004 in the 60-year weather record at the South Pole Station."

The NSIDC report also added that for the polar darkness period from April through September, the average temperature was -60.9 degrees Celsius (-77.6 degrees Fahrenheit), "a record for those months."

The report was covered in newspapers as well as in online articles. But some social media posts sought to use the findings to claim global warming is a hoax.

The record does not, however, mean climate change is not occurring, even at the poles. Scientists agree that Antarctic ice sheets will continue to melt and increase sea levels.

Data from NASA's satellites shows that the land ice sheets in both Antarctica and Greenland have been losing mass since 2002.

"The Greenland and Antarctic ice sheets are losing significant amounts of land-based ice as a result of human-caused global warming," NASA says.

A screenshot taken on October 21, 2021 of a NASA chart about Antarctica's ice mass variations

Peter Jacobs, a climate scientist who works in Earth Science for NASA Goddard Space Flight Center's office of communication, told AFP that "we know from basic physics, climate modeling, and changes from Earth's past that increased greenhouse gases and warming will melt Antarctic ice and increase sea levels."

"Overall, the South Pole has been warming, and the warming over recent decades has actually been quite rapid due to both human-driven climate change and natural factors," he added.

Nanna Karlsson, glaciologist and senior scientist at the Geological Survey of Denmark and Greenland. agreed. "The recent temperature record in Antarctica is a weather event, while the long-term global warming we observe is climate. Weather can be very variable and exhibit record-breaking cold (or warm) temperatures. Climate is a trend over several decades," she said.

Weather events are often mischaracterized by conspiracy theorists and climate change deniers, according to polar historian Ursula Rack. "It is of course convenient to see only one part of the story," she said.

Alison Banwell, research scientist and glaciologist at the Cooperative Institute for Research In Environmental Sciences, said it is clear that humans are driving the current long-term global warming trend.

"Overall, the Earth's climate, including Antarctica, is showing a very clear warming trend," she said.

"As the global climate warms, weather events will also become more extreme. A good example of such extreme variability was this recent exceptionally cold winter over Antarctica," Banwell added.

A strong polar vortex is the likely cause of the record cold, according to Isabella Velicogna, who monitors Antarctica's ice mass variations for NASA's Jet Propulsion Laboratory in the Sea Level and Ice Group.

The vortex is formed by stronger winds than usual. "This keeps the cold air stock at the pole," she said.

Samantha Buzzard, a glaciologist and climate scientist at Cardiff University in Wales, said that "while Antarctica did experience some low temperatures this year, this one-off event doesn't mean we shouldn't be worried about climate change and ice loss from the polar regions."

"One cold winter on one continent doesn't suggest the planet isn't warming," she added.

The researcher said this year's harsh winter should be put back in a context of several decades of climate trends to understand what is happening in Antarctica, adding that just last year, the continent also hit a record-high temperature.

Map of Antarctica locating Argentina's Esperanza Base. The World Meteorological Organization confirmed a record high temperature for Antarctica there on February 6, 2020 ( AFP / Nick Shearman, STAFF)

"We should absolutely still be concerned about Antarctica," Buzzard said.

"Around 70 percent of Earth's fresh water is currently in frozen in Antarctica and only a small proportion of that has to melt for there to be further increases in sea level with potentially devastating consequences in many locations worldwide."

October 28, 2021 This article was updated to add a missing letter in the 12th paragraph.