The seasonal expansion and contraction of Arctic sea ice have come to a worrying standstill this year, with ice still yet to form in a key region off the coast of Siberia – despite the fact that we are already in late October. This is the first time in recorded history that the Laptev Sea has failed to freeze this late in the year.
Typically, sea ice in the Arctic melts during the summer months and refreezes in the winter, yet the extent of the annual melt has been increasing for a number of years, with the first ice-free Arctic summer expected to occur between 2030 and 2050. This year has been particularly catastrophic for the region, with an unprecedented heatwave causing temperatures to soar to 10°C (18°F) above average in Siberia in June.
Now that winter is approaching, the full impact of this year’s scorching summer is becoming clear, as the Arctic’s premier ice nursery in the Laptev Sea has failed to freeze, with major consequences for the polar region as a whole.
Normally, ice forms along the northern Siberian coastline in early winter and is then blown out across the Laptev and beyond by strong winds. As it travels, it carries nutrients across the Arctic before finally melting in the Fram Strait, between Svalbard and Greenland, in spring. However, a later freeze means that any ice that does form this year will have less time to thicken, increasing the likelihood of it melting before it reaches the Fram Strait.
As a consequence, plankton throughout the Arctic will receive less nutrients, thereby reducing their capacity to remove carbon dioxide from the atmosphere. This, in turn, will contribute to the greenhouse effect, resulting in higher global temperatures and even less ice.
“The lack of freeze-up so far this fall is unprecedented in the Siberian Arctic region,” said Zachary Labe from Colorado State University in an email to The Guardian.
“2020 is another year that is consistent with a rapidly changing Arctic. Without a systematic reduction in greenhouse gases, the likelihood of our first ‘ice-free’ summer will continue to increase by the mid-21st century.”
The extreme summer temperatures experienced across the far north this summer caused the Laptev Sea ice to melt earlier than ever before this year, leaving vast areas of open water exposed. As this water absorbed sunlight, it reached a temperature of 5°C above average. Fast-forward a few months, and the increase in water temperature is delaying the winter freeze.
“The amount of open water this fall is absurd. We have to pay attention to these climate change indicators,” insisted Labe, referencing the fact that the Laptev Sea’s failure to freeze has resulted in record low sea ice coverage across the Arctic this year.
What’s more, with this year’s curtailed freeze likely to produce thinner ice, the chances of an even earlier melt next year are high. This would result in even more open water throughout the summer, possibly leading to a greater rise in ocean temperatures than was seen this year, and culminating in an even later refreeze next winter.
With the spiral having already been set in motion, Labe and other climate scientists say the clock is very much ticking for policymakers to act in order to curb emissions and save the Arctic sea ice.