When the Konger Ice Shelf, an Antarctic ice shelf the size of Rome, collapsed in March, the scientific community was shocked. Never before has an ice shelf collapsed in East Antarctica. collapse fell Together with a “heat wave” Temperatures during it sometimes reached 40 degrees Celsius above normal. “Partial temperatures were measured at -12 degrees,” said Zoe Thomas, an Antarctic expert at the University of New South Wales in Sydney. “This is clearly an anomaly for the region.” Normally, temperatures should be around 50 degrees below zero.

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A few days after the Antarctic temperature record and the collapse of the Conger ice shelf, New Zealand also reported that its glaciers had collapsed due to The consequences of climate change It has shrunk dramatically and is now only “structural”. Scientists now expect many to be completely gone within a decade.

Since 1900, the seas around the world have risen by about 20 cm

Are these few critical days in mid-March a preview of what’s to come? Because melting ice combined with the potential collapse of ice shelves and melting glaciers such as Pine Island or Thwaites in West Antarctica could cause sea levels to rise by several metres. 129,000 years ago, melting ice in Antarctica caused a sharp rise in sea levels.

Since 1900, the seas around the world have risen by about 20 centimeters. But the increase is accelerating: a quarter of this has occurred since 2006. Sea levels are currently rising at a rate of 3.7 mm annually. Scientists expect a rise of at least 28 centimeters by 2100, but depending on how much ice is melting, sea levels could rise by up to two metres.

Especially if glaciers such as Pine Island or Thwaites collapse, it can lead to a kind of domino effect. The Thwaites Glacier has an area of ​​192,000 square kilometres, which is roughly the size of Great Britain. If the ice shelf collapsed there, global sea level would rise by about 65 cm. In addition, the glacier is also stabilizing the entire West Antarctic ice sheet, which could raise sea levels by up to three meters if it melted completely.

The ice on the Thwaites Glacier has been getting increasingly fragile, less and less for years. “Right now, the glacier is losing about 50 billion tons more annually than it gains from snowfall,” said Keith Nichols, an expert on the British Antarctic Survey, in a 2020 interview. “Yes today, the glacier contributes about four percent annually to sea level rise.

Cities like San Francisco, New York, Miami, London or Jakarta will be flooded. For some Pacific countries such as Kiribati or low countries such as the Netherlands or Bangladesh, the consequences will be so disastrous that some media have dubbed it the “Doomsday Glacier”.

Three main factors contribute to ice shelf collapse: rising ocean temperatures, rising atmospheric temperature, and the amount of sea ice. “So you have the ice cap that’s on land, the ice shelf – the floating pieces of ice – and then the sea ice,” explains Zoe Thomas. “Sea ice typically stabilizes the ice shelf in a similar way as the ice shelf stabilizes the ice sheet on land.” However, a significant decrease in sea ice has been recorded this season. “This makes the ice shelves vulnerable to waves and other atmospheric influences,” she said.

680 million people live near coasts or islands

According to Thomas, models show that human-caused climate change has caused many of these changes in Antarctica. What is particularly frightening is how much sea-level rise has accelerated in recent years. “The time frame was several hundred years, and now we’re talking about two or three decades – so it can happen to all of us in our lifetimes.”

About 680 million people live in the immediate vicinity of coasts or on small islands, according to a report by the German Climate Consortium and the German Marine Research Consortium. There will also be an “increased risk” to Germany’s North Sea and Baltic coasts and to cities such as Bremen or Hamburg, where storms could occur more frequently and at higher levels in the future.