Arctic researchers want to state their case before international climate change policy makers – Cape Cod Times

Ice melting endangers polar bears

As world leaders meet in Glasgow, Scotland, to try to ramp up efforts to curb climate change, the spectre of polar bears looms over them. The Arctic has been warming twice as fast as the rest of the world. Scientists and advocates say the threatened animals are "the canary in the cryosphere."

AP

Rachael Treharne, an Arctic ecologist at the Woodwell Climate Research Center in Falmouth, returned to her Oxford, England home after nearly two weeks in Glasgow at Cop26, the United Nations 2021 climate change conference, that was still struggling to finish up last-minute negotiations over the weekend.

With the Arctic region warming at three times the global rate, profound and rapid change is evident everywhere from the Greenland ice sheet to the ocean ecosystem and the permafrost underlying much of the landmass. The testimony of indigenous people who live within the forests, deserts and tundra, as well as regions where snow and ice dominate, moved her.

But the grinding pace of negotiations on emissions, finance, and culpability, in the face of rapid, relentless changes being documented by researchers and the regions 5 million inhabitants, she found soul-crushing.

Its so slow and not on a scale of whats happening, said Treharne in a phone interview Friday.

Perhaps that sparse constituency helps to explain why, despite its potential to exert an outsized influence on carbon emissions, sea-level rise, and fisheries, the Arctic has largely been left out of climate change discussions and calculations on how to ease global warming.

A panel of Arctic researchers and policy analysts from the Woods Hole Oceanographic Institution and the Woodwell Climate Research Center made the case last week at the Glasgow conference for elevating the Arctic to the forefront of the climate discussion, asking for more research and greater incorporation of polar warming into climate change discussions and modeling.

It contains some of the most beautiful and wildest landscapes weve got left, said Treharne. It is the only place where the plants huddle together for warmth and it has such a rich and multifaceted cultural significance to the people who live across the Arctic.

There is a delicate balance to life at the extremes of what can be endured but the regions integrity is rapidly coming undone by human-induced climate change. Loss of reflectivity, as the regions sea ice and snow cover disappear, means more of the suns energy is absorbed into its seas and land. Plus changes in currents in the sea and atmosphere bring warmer water and air temperature to the Arctic which saw record-breaking 100-degree temperatures in some locations in August 2020.

While negotiators at Cop26 haggled over how to avoid a 1.5 degree Celsius (2.7 F) increase in global mean temperature, WHOI glaciologist Sarah Das, speaking as one of the climate change conference panelists highlighting the dire outlook in the Arctic, pointed out that it only takes a few tenths of a degree difference in temperature to go from ice to water.

The ice across Greenland is extremely susceptible to these changes, said Das in an interview Friday.

While the disappearance of relatively small glaciers makes for front-page news, those are relatively small reservoirs of freshwater when compared with the Greenland ice sheet which covers an area roughly three times the size of Texas and is nearly three miles high at its thickest point.

Until recently, Greenlands ice cap was relatively stable. Ice and snow loss each summer was offset by winter accumulation. But in 1990, it became unbalanced, Das said. Wetter ice is darker ice and absorbs more of the suns heat amplifying the melt.

As a result, the Greenland ice sheet annual ice loss has accelerated from less than one gigatonne per year in the 1990s to 345 by 2011, according to a 2019 study by an international panel of polar scientists known as the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). According to NASA, a gigatonne is the equivalent of 10,000 fully-loaded U.S. aircraft carriers.

The IMBIE study showed that Greenlands ice was disappearing at a rate close to that used by the international Intergovernmental Panel on Climate Change for their high-end climate warming scenario.

Over the course of a single generation, weve gone from a stable Greenland ice sheet to one that is rapidly declining, said Das. We are running full speed towards the abyss.

While the earth enters an ice age every 100,000 years, Das said that warming due to human greenhouse gas emissions has removed the earth from that cycle.

We have exited that world entirely, she said. The disappearance of the Greenland ice sheet has sea-level consequences. A complete melt could lead to over 20 feet of sea rise, according to the National Snow and Ice Data Center.

Two hundred and thirty million people currently live less than a meter below current high tide lines; 190 million more will be imperiled under the low carbon emissions scenario and 630 million projected using the high emissions calculation.

Das said the heat increase in the atmosphere today may have already doomed Greenlands ice cap. The question now in reducing emissions is one of delaying it enough, hundreds, possibly thousands of years, to give us time to adjust.

A marked change in a system, now ongoing in the Arctic, is not what we want. Its not beneficial to us because of the Arctic role in weather, in holding frozen water and in freezing organics (like the greenhouse gases methane and carbon dioxide bound up in permafrost) said Carin Ashjian, a biological oceanographer and chair of the biology department at WHOI. Ashjian also spoke on the Arctic panel at the Glasgow conference.

Theres so many ways it could impact us in lower latitudes and that system is changing markedly, she said in a phone interview after returning from Cop26. Philosophically, the idea of losing such a remarkable system is an incredible loss in and of itself.

Ashjians work is focused on ocean currents and temperature distribution impacts on the polar marine ecosystem, and she has been on over 60 Arctic cruises, including long-term studies on icebreakers that purposefully become icebound and drift with ice packs.

Quite often, the ice they sampled had survived through several winters. But with warming sea and air temperatures, the sea ice has been melting to a far greater extent and taking longer to freeze up again.

Increasingly, more of the Arctic is first-year sea ice, said Ashjian, which is not as hard as multiyear ice and more susceptible to melt.

What researchers have found is that warmer water marine species have expanded into the polar regions and the Arctic species moved even farther north. While that may be beneficial in some instances, like increased catches of salmon in northern Alaskan waters, it can also have profoundly negative consequences like the spread of algae that produce saxitoxins and domoic acid that can kill people and marine life. Ashjian said it is the rate of change in the Arctic that jeopardizes the resilience of ecosystems and those who depend on it.

If things change too much for local communities, they can run into all kinds of problems with food insecurity, she said. The animals they hunt and fish are also important to the culture of subsistence hunting communities.

As scientists, we can continue to try to understand the consequences of change on this ecosystem, and we dont understand it that well, said Ashjian. Its hard for scientific research, which moves at a very deliberate pace that can take years to complete a single study, to keep pace with the rapid changes the Arctic is undergoing.

It can take seven or more years for research to become policy, said Ashjian, But look at sea ice change and its a pretty steep slope there.

The Arctic is a hard and expensive place to do research and its the unknowns and the relative paucity of research that worries Treharne. While she largely works on climate models now, Treharnes earlier fieldwork looked at the impacts of warming on permafrost, the layer of frozen soil that doesnt thaw in summer and is present in 22% of the earths landmass.

Permafrost is both integral to the landscape and ecosystems, particularly in the Arctic Boreal Zone, but also contains massive amounts of organic matter from decomposed plant life. Treharne compared the permafrost to an enormous frozen compost heap that, when thawed, would begin releasing the organic gases of decomposition. A complete thaw could unleash twice the amount of carbon into the atmosphere contained in all the trees on the planet. If just 10% of the carbon dioxide in permafrost ends up in the atmosphere, Treharne said, it could add an amount equivalent to half the total emissions from humans over the past century, citing a recent IPCC special report on the cryosphere and oceans.

Plus, permafrost is the foundation of the Arctic boreal landscape. Thawing causes massive slumping of land, releases sedimentation into rivers, and affects groundwater flow and retention to the point where it can cause dramatic local ecosystem changes, creating wetlands and deserts.

Treharne said researchers expect to see the loss of between one-quarter to three-quarters of permafrost by the end of this century. But the full extent of the problem is not known because the permafrost region is vast and remote. With Arctic science still evolving, only a small percentage of carbon emission models use permafrost data, said Treharne. And none use estimates of the increasing number and breadth of arctic fires in permafrost thawing.

The last IPCC report did make a preliminary estimate of the impact of gradual thawing, said Treharne, but didnt account for rapid thaw or fires.

Today, were causing huge changes. How much worse it gets depends on us, said Treharne.

International climate change policy tends to focus on areas where the science is robust. Arctic scientific research is still evolving, but the risk of irreversible and potentially devastating impacts is too great to delay. Treharne said Arctic scientists, including researchers from WHOI and Woodwell, were advocating for an international cryosphere dialogue; an international structured discussion among scientists and policy makers around issues like permafrost and the Greenland ice sheet. They are hoping that will happen this summer.

We just want one chance to talk about it, said Treharne. We want to state the case, but its also the opportunity to explain the information you dont have and delegates can ask questions.

Follow Doug Fraser on Twitter:@dougfrasercct.

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Arctic researchers want to state their case before international climate change policy makers - Cape Cod Times