The sea ice that packs the ocean around Antarctica has hit extremely record low levels this winter, adding to scientists’ fears that the impact of climate change at the southern pole is ramping up. Scientists at the U.S. National Snow and Ice Data Center (NSIDC) said on Monday that the ice extent has been lower than ever recorded this winter — the middle of the Antarctic season.
The team said that’s an area just a bit bigger than Texas and follows a trend toward less-than-normal sea ice that began in 2016 and shows no sign of letting up. Researchers warn that the shift can have dire consequences for animals like penguins, who breed and rear their young on the sea ice. It can also hasten global warming by reducing how much sunlight is reflected by white ice back into space.
Sea ice is essential to many Antarctic species. It usually covers an area twice as big as the United States by October each year, and it’s essential for breeding birds, such as penguins. When it melts, they can’t find places to nest. And it can force them to lay eggs at unnatural times of the year, causing their chicks not to develop properly or to be lost in drifting ice floes, says one of the scientists involved in the new study published in the journal Science Advances.
As a result of the sea-ice decline, the breeding success of some penguin colonies has been “catastrophic,” the research team said. The findings are a wake-up call, says another of the scientists. “As soon as we see this loss level, you have to wonder whether we’re seeing the tipping point,” he told CNBC.
Usually, sea ice peaks in September, near the end of the Antarctic winter, and begins to melt in February or March as summer approaches. But this year, the ice reached record lows well before those dates.
It’s unclear why this has happened, but the research team suspects that warm air and water from the Arctic are to blame. The Arctic has warmed four times faster than the rest of the globe, and its melting glaciers have exacerbated the sea-ice decline.
This decline has alarming implications for Antarctica, says Eduardo Oliveira, a meteorologist at Uruguay’s King George Island scientific station. He has worked in the region for 20 years and has seen several changes: rising temperatures that have caused melting glaciers, rain instead of snow that can wash away nutrient-rich krill, and a warmer, acidic sea poisoning coral reefs. The thinning ice is a particularly troubling development, he tells CNBC. It means that fewer penguins can survive the harsh Antarctic winter. That could lead to a cascade of problems: the birds’ intestinal flora can be affected; they won’t be able to breed successfully, and they can die on floating ice. And the continent’s polar bears and seals will also be at risk.
