Some scientists believe that the Arctic's melting sea ice can be restored
As the Arctic slipped into the half-darkness of autumn last year, all manner of strange things happened. The sea ice covering the Arctic Ocean started to shrink when it should have been growing. Temperatures at the North Pole soared more than 20 degrees Celsius above normal at times. And polar bears prowling the shorelines of Hudson Bay had a record number of run-ins with people while waiting for the water to freeze over. It showed just how quickly climate change is reshaping the far north.
As early as 2030, researchers say, the Arctic Ocean could lose essentially all of its ice during the warmest months of the year. This extreme transformation would upend Arctic ecosystems and spill beyond the region. An increasingly blue Arctic Ocean could cause temperatures to soar. It may even scramble weather patterns around the globe.
But as some researchers look even further into the future, they see reasons to preserve hope. They believe that the same phenomena that makes it easy for Arctic sea ice to melt rapidly may also allow it to regrow. Stephanie Pfirman, a sea-ice researcher, says that it’s time to look beyond the Arctic’s decline. Instead, we should start thinking about what it would take to restore sea ice.
Entire Coastal Communities Will Be Forced To Move
Sea-ice researchers aren’t counting on the chance that the world could prevent the total loss of summer sea ice. Models have consistently underestimated ice losses in the past. This has caused scientists to worry that the declines in the following years will happen faster than scientists previously thought.
The Arctic’s 4 million residents will feel the most direct effects of ice loss. Entire coastal communities, such as many in Alaska, will be forced to move as permafrost melts and shorelines crumble into the sea. But the effects could reach around the globe. Sea ice helps to cool the planet by reflecting sunlight and preventing the Arctic Ocean from absorbing heat.
But Arctic ecosystems will take the biggest hit. The changing Arctic will pose a challenge for species whose life cycles are intimately linked to sea ice. Those at risk may include walruses and Arctic seals — as well as polar bears, which don’t have much to eat on land. Research suggests that many will starve if the ice-free season gets too long in much of the Arctic.
Shores Of Greenland And Canada Likely To Fare The Best
Ice-dependent ecosystems may survive for longest along the rugged north shores of Greenland and Canada. Wind patterns cause ice to pile up there. The thickness of the ice — along with the high latitude — helps prevent it from melting. Groups such as the wildlife charity WWF have proposed protecting this "last ice area." They hope that it will serve as a life preserver for many Arctic species.
But not all species live in the region, and those that do are there in only small numbers. Biologist Andrew Derocher estimates that there are less than 2,000 polar bears in that last ice area today. How many bears will live there in the future depends on how the ecosystem evolves with warming.
There is one source of optimism: summer sea ice will return whenever the planet cools down again. But identifying the exact threshold at which sea ice will return is tricky, says sea-ice researcher Dirk Notz. Researchers suggest that the threshold hovers around 450 parts per million (p.p.m.). This is 50 p.p.m. higher than today. Society may not be able to forestall the loss of summer sea ice in coming years. But taking action to keep CO2 concentrations under control could still make it easier to regrow the ice cover later, Notz says.
Pros And Cons Of Geoengineering
Given the stakes, some researchers have proposed global-scale geoengineering to cool the planet. This will preserve or restore the lost ice. Others argue that it might be possible to chill just the north. For instance, the Arctic Ocean may be artificially whitened with light-colored floating particles to reflect sunlight. A study this year suggested installing wind-powered pumps to bring water to the surface in winter, where it would freeze, forming thicker ice.
But many researchers are wary about geoengineering. And most agree that regional efforts would take tremendous effort and have limited benefits. In fact, the Earth’s circulation systems could just bring more heat north to make up for this. Pfirman and others agree that managing greenhouse gases and local pollutants is the only long-term solution.
Some researchers also say that the idea of regrowing sea ice seems like wishful thinking. It would require efforts well beyond what nations have already agreed to do. And if summer sea ice ever does come back, it’s hard to know how a remade Arctic would work, Derocher says. He says that while there will be an ecosystem, it just may not look like the one we currently have.