Resilience of the Thickest Arctic Ice Is Cracking

Hole the size of Rhode Island opened in the Arctic ice for 2 weeks in 2020 and that will be nothing if we don’t curb emissions, warns ‘alien Earth’ forecast for the year 2500

Ruth Schuster
Ruth Schuster
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Eureka Sound on Ellesmere Island in the Canadian Arctic.
Eureka Sound on Ellesmere Island in the Canadian Arctic.Credit: NASA ICE
Ruth Schuster
Ruth Schuster

Climate change is taking Earth and its passengers into uncharted territory. We have an idea of the trajectory but not the pace. Now, a huge rift in the thickest ice in the Arctic, which developed in 2020 and lasted two weeks, has been reported.

For that fortnight, there was a pool of open water almost as big as Rhode Island, according to a new study published in the American Geophysical Union journal Geophysical Research Letters.

True, Rhode Island is the smallest U.S. state at 3,144 square kilometers (1,214 square miles) in area. The rift is about 3,000 square kilometers. Yet though by criteria of states the island is tiny, by criteria of climate change the rift is big – and significant.

The area of open sea water, called a polynya, is the first to be detected north of Ellesmere Island (Canada’s northernmost island), the AGU stresses. It developed in the Last Ice Area, a million-square-kilometer area of sea ice north of Greenland that, the researchers explain, has been assumed will be the last bastion of ice in the Arctic.

The Arctic Circle in general has been experiencing accelerated climate change. If the mean global temperature has increased by about 1.2 degrees Celsius so far, which is bad, the mean Arctic temperature has increased by more than 3 degrees – three times greater than the global increase from 1971 to 2019. The Arctic has also been experiencing an increase in extreme weather resulting in accelerated ice loss. Among the extreme events, we now know, was the development of this state-sized polynya in May 2020.

We will ignore shippers hailing the meltdown as a boon to maritime cargo traffic and focus on the dangers represented by the pool of open water: the purported last refuge of ice in the Arctic sprang a giant hole and may be more vulnerable to climate change than thought.

The ice where the polynya suddenly gaped is up to 5 meters thick, the researchers say. They hadn’t observed polynyas form there before, explained lead author Kent Moore of the University of Toronto-Mississauga.

Technically, the hole was caused not by melting but by anomalous winds, the researchers explain – a high-pressure storm that “pushed” the ice aside, which is not a rare thing in the Arctic in general but hadn’t been observed to that degree in the Last Ice refuge before.

It could be viewed as a form of extreme weather, because the winds were stronger than usual for that area.

A satellite image of the 3,000-square-kilometer polynya observed north of Ellesmere Island, Canada.Credit: NASA EOSDIS Worldview

Feeling the heat in Arabia

Even if the Arctic is more resilient or less, it bears adding that vulnerability to climate change is a matter of pace and time, not trajectory at this stage – the trajectory is clear, and it’s not good.

Nowhere on Earth is “safe” from climate change. Many forecasts focus on the year 2100 for no reason whatsoever: that is not a cut-off point, it is an arbitrary convenience.

But it bears a terrible price – action plans, such as they are, aren’t even looking past that point. And they desperately need to, according to an article published last month in Global Science Biology. As Science Alert warned based on that: “By 2500, Earth will be alien to humans if we don’t act now.”

So what will the world look like in the year 2500, according to Christopher Lyon of McGill University, Montréal, et al? If we do nothing to curb greenhouse gas emissions – and they’re picking up, not declining: hydrocarbon extraction in the Middle East trundles on –  they warn that “without deep and rapid reductions in greenhouse gas emissions, climate change will continue for centuries into the future.”

Models that go beyond the year 2100 lack the necessary complexity, but even so the team has a stab at creating a crude model based on three scenarios representing strong, moderate and weak global climate policy.

The relatively good news, according to the models, is that if humanity stops navel-gazing and curbs emissions strongly, the global mean temperature should stop rising before 2100 and could even decline slightly by 2500 – though it would still be beyond the preindustrial level.

And if we don’t? (And so far, we aren’t.) Under the moderate to high emissions scenario in this model, the world mean temperature will rise by 2.2 degrees Celsius above present-day levels by 2100, 3.6 degrees by 2200 and 4.6 degrees by 2500. (Some predict more.) India for one will become too hot to live, Scientific American points out.

Still not impressed? The world will be unrecognizable, from sea to shining, warming sea. The Amazon will be all but gone, and so will many of the coastlines we know today, as sea level is expected to continue rising long after the temperature has stabilized because of the lag of heat mixing into the deep ocean.

Can we survive that? Hard to say at this point, but some areas are already reporting brief, but telling, deadly heat waves, which will spread to temperate zones – including the Mediterranean – as the climate warms. The Arabian Peninsula experiences heat stress during 25 percent of the year: that figure is expected to double, according to the scientists’ crude model.

Yet if emissions are curbed, heat stress in Arabia, Australia and other places isn’t expected to worsen beyond 2100.

Arctic ice floes and melt pools, with a polynya visible to the right.Credit: Collection of Dr. Pablo Clemente

As for the polynya – remember that? – the researchers warn that these holes in the thick ice could happen more often as the Arctic ice thins, setting off a feedback loop of ice loss.

“The thing about thinning ice is that it’s easier to move it around. As the ice gets thinner, it’s easier to create these polynyas with less extreme forcing, so there is some evidence that these polynyas may become more common, or become larger, than they were in the past,” Moore said in a press release.  

Seals like polynyas, the researchers note. Whole ecosystems can suddenly form around these transient holes in the ice, but if the planet gets so warm that the northern-cold-adapted species go extinct, that will be precious little comfort.

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