When Does Arctic Sea Ice Normally Refreeze?

For the very first time in recorded history, the main tranche of Arctic Sea ice has still not frozen into mid-October. Located in the Laptev Sea in Siberia, the ice normally thaws during the summer months, but begins to refreeze in mid-September. 2020 is the first year on record that such an occurrence has failed to happen, causing concerns about the long-term repercussions of the phenomenon.

Climate scientists believe that an unusually long summer enjoyed by the north of Russia has combined with an influx of Atlantic currents bringing warmer water, which has prevented the sea from freezing over as it normally would. The probability of this year’s heatwave was increased by a factor of 600 due to the anthropogenic emissions created by industry and agriculture, according to a recent study.

An anomalous year

By the start of October, there is normally at least 100,000 square kilometres of ice in the Laptev Sea, which is the main nursery for Arctic ice, while in some years, the figure is far higher. By the start of November, the ice has usually reached its peak of approximately 850,000 square kilometres, but this year has witnessed very little freezing by comparison.

“The lack of freeze-up so far this fall is unprecedented in the Siberian Arctic region,” explained Zachary Labe, a postdoctoral researcher specialising in this subject from Colorado State University. “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.”

Huge consequences

The news is concerning for a number of reasons. For one thing, the later freezing time is likely to contribute to thinner sheets of ice covering the Arctic Sea throughout winter, which means it will thaw earlier and potentially freeze later next year. This could not only lead to a sizable increase in sea levels, but also trigger an exponentially spiralling system of warmer temperatures.

Another concern involves the vast amounts of methane reserves that are stored in underwater Arctic ice. As a greenhouse gas with a global warming potential (GWP) 28 times that of carbon dioxide, methane monitoring is an absolute must. There are worries that if the surface ice is taking longer to freeze, it’s only a matter of time before the subaquatic ice thaws as well, releasing huge concentrations of methane into our atmosphere.

Humans to blame

If this downward trend continues as expected, it’s only a matter of time before the Arctic experiences its first ice-free winter, with experts predicting that event to come about between 2030 and 2050. While it’s difficult to trace the phenomenon back to any one contributing factor, the anthropogenic emissions engendered by the Industrial Revolution have played a huge part in making these events more likely.

In order to avoid a worst-case scenario, it’s imperative that global emissions are brought under control. Despite widespread agreement that concrete actions must be taken, many EU countries are falling behind on achieving their targets with regard to greenhouse gas emissions. If one of the world’s most developed and economically powerful blocs can’t achieve their goals, there’s little hope that more impoverished nations can, either.