Antarctica, the icy continent at the bottom of the world, has likely reached its lowest annual ice level ever recorded. Scientists are alarmed by these developments, fearing that global warming may be driving the region into a new era of diminishing ice, which could have significant repercussions on the world’s climate and sea levels.
A Record Low
Each year, during September, Antarctica’s sea ice typically reaches its maximum extent. Over the period from 1981 to 2010, the average extent was 18.71 million square kilometers.
However, preliminary analysis from the US National Snow and Ice Data Center (NSIDC) suggests that this year, on September 10th, the sea ice reached a maximum of just 16.96 million square kilometers and has since continued to decline.
This year’s maximum sea ice extent is 1.75 million square kilometers below the long-term average and nearly one million square kilometers less than the previous record low set in 1986.
Dr. Will Hobbs, a sea ice scientist at the University of Tasmania, noted that the growth rate of Antarctica’s sea ice has been “very, very slow” since April, signaling that something significant was happening.
Sea ice losses in the Ross Sea region were attributed to winds pushing the ice against the continent, bringing warmer air. However, the reasons for ice loss in other parts of Antarctica remain unexplained.
A Sudden Shift
Antarctica’s sea ice undergoes an annual cycle, reaching its lowest extent in February and its highest levels in September. It had remained relatively stable until it broke its previous record low in 2016. This trend continued with further record lows occurring, including this year’s February minimum.
In February, during the height of the austral summer, Antarctica’s sea ice had reached a minimum extent of 1.79 million square kilometers, also a record low, according to the NSIDC. Surprisingly, despite the onset of winter, the ice pack’s growth rate was slower than usual.
Antarctica’s sea ice had remained relatively stable and even expanded slightly for several decades. However, since August 2016, a sharp downturn in the sea ice extent trend has been observed throughout most months of the year, according to the NSIDC.
Meanwhile, in the Arctic, where summer was coming to an end, the sea ice reached a minimum extent of 4.23 million square kilometers, marking the sixth lowest minimum in 45 years.
Is it Climate Change?
Scientists are still investigating the causes behind this dramatic shift in sea ice levels, with natural variability and global warming likely playing roles.
While some scientists hesitate to attribute these records to global warming, the loss of sea ice aligns with climate change projections.
According to the NSIDC, the losses of sea ice since 2016 are most likely linked to the warming of the upper layer of the ocean.
This could signify the beginning of a long-term decline in Antarctic sea ice, given the global warming of oceans. The NSIDC also raises the possibility that waves impacting the ice sheet might increase “accumulation near the coast, offsetting in part the threat of rising sea level.”
The repercussions of dwindling sea ice are profound. Sea ice acts as a barrier, preventing land-based ice from entering the ocean and causing sea levels to rise.
Additionally, sea ice reflects sunlight back into space. With less sea ice, more of the ocean is exposed to the sun’s energy, causing further warming in the Southern Ocean and contributing to ice loss.
Dr. Ariaan Purich, a climate scientist specializing in Antarctica, expressed concern about the future, stating, “I’m worried that it looks like low sea ice is the future – and it’s here now.”
Walt Meier, a scientist at the NSIDC, described it as a “record-smashing sea ice low in the Antarctic,” and that the low growth in sea ice occurred uniformly around the continent. This uniformly low growth indicates that the ice loss is not region-specific and is a global issue.
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