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The part of Earth’s surface lying north of the Arctic Circle encompasses an area of 7.7 million square miles, of which 70 percent is open or ice-covered ocean. Only eight nations possess territory or territorial waters in this region: the United States (because of Alaska), Canada, Russia, Finland, Norway, Sweden, Iceland and Denmark (because of Greenland). A mere 4 million people inhabit the Arctic. Indigenous people make up about 10 percent of the total, spread across two dozen ethnolinguistic groups (e.g., Inuit, Aleut, Saami).

Beyond its value to the people who live there, however, the Arctic has long been recognized as having considerable importance beyond the region. It is significant militarily, because of the Arctic’s location, linking all of the world’s northern land masses. It’s also significant economically for its oil, gas, strategic metals, and ocean fisheries; and it’s prized around the world, even by people who will never see it in person, for its spectacular landscapes and wildlife.

For the last couple of decades, though, climate change has been transforming practically everything about the Arctic that matters to people both inside and outside of the region. That’s because the Arctic as a whole has been warming two to three times faster than the rest of the world. The accumulating effects of this extreme warming are now manifesting themselves in a multiplicity of ways, some of them creating new economic opportunities, but practically all of them creating major physical, socioeconomic and management challenges for the region. And, of greatest importance for rest of the world, the rapid pace of climate change in the Arctic is influencing the pace and impacts of climate change elsewhere.  It even threatens to undermine the ability of society’s emissions reductions to stop warming worldwide at a level that avoids wholly unmanageable consequences.

A major factor in the rapidity of Arctic warming is what climate scientists call “the snow-ice albedo feedback.” Albedo simply means the fraction of incident sunlight that is reflected rather than absorbed. A warming atmosphere reduces snow cover, replacing highly reflective snow with highly absorptive dirt and vegetation, thus magnifying the initial warming. 

Similarly, when sea-ice cover on the Arctic Ocean is reduced in consequence of a warming environment, incoming sunlight strikes highly absorptive water where it previously struck highly reflective ice; again, the result is magnification of the initial warming. 

The area covered by sea ice in the Arctic in summer is now barely more than half of what it was in 1979, when accurate satellite measurements began. The decline in sea ice opens the possibility of summer trade and tourism routes that have been impractical until now, as well as expanded access to sub-seabed resources and Arctic Ocean fisheries.

Most of these opportunities are mixed blessings, though. Expanded ship travel through the Arctic poses major pollution risks in a fragile region — and would require significant investments in capabilities for monitoring ship traffic and for search and rescue. Extracting Arctic resources of oil and natural gas involves costly and perilous operations in an unforgiving environment, in pursuit of carbon-rich fuels the world needs to be burning less of, not more, if climate change is to be reined in. And as for Arctic Ocean fisheries, the magnitudes and sustainable yields of the resource are largely unknown.

At the same time, the shrinkage of the Arctic sea ice carries large physical and biological liabilities. Iconic marine mammals that are important for subsistence livelihoods in the region — whales, walruses, seals, polar bears — depend on sea ice for feeding or breeding. Additionally, the retreat of sea ice from shorelines exposes them to storm waves that the ice previously kept at bay. This results in heavy damage to the coastal communities where most of the Arctic’s Indigenous people live. Some of these communities have little choice now but to relocate inland, even though the costs of doing so are extremely high.

Other major impacts of rapid climate change on the residents of the Arctic include the thawing of the permafrost — frozen soil — that underlies most of the land in the Arctic; and the striking expansion of wildfires in the region. Thawing permafrost results in subsidence, causing buildings to crack, roadways to collapse and pipelines to fail. King salmon populations that are important economically and for the subsistence of Indigenous people are in decline across most of Alaska. Heat, drought and increased lightning have led to increased wildfire all across the Arctic. In Alaska, the average annual area burned has more than doubled since the 1980s. Wildfires destroy vegetation and wildlife, emit large quantities of carbon dioxide, accelerate the thawing of permafrost and spread toxic smoke across huge distances, in some cases reaching down into the mid-latitudes.

The biggest impacts of Arctic climate change outside of the region are:

Annual losses from the Greenland Ice Sheet to the ocean have increased six-fold since the 1980s, becoming the largest single contributor to global sea-level rise. 

The contributions of thawing permafrost to the atmospheric burden of heat-trapping carbon dioxide and methane have been growing. Permafrost soils contain more than twice as much carbon as the atmosphere currently holds. There is considerable scientific uncertainty about how much of this gigantic total will be released as carbon dioxide and methane over the coming decades. It could be enough to significantly accelerate global warming and, indeed, to render unattainable the Paris Agreement’s targets for stabilizing the Earth’s temperature.

Understanding rapid climate change in the Arctic, then, is important for understanding the scope of the climate challenge globally — and critical for fashioning badly needed adaptation strategies in the region. Increased international efforts in Arctic science have been underway for some time, but they need to be expanded. People and policymakers everywhere need to recognize the importance to all of us of what is being learned — and lost — in the Arctic.   

John P. Holdren, Ph.D., is the Teresa and John Heinz professor of environmental policy in the Kennedy School of Government, professor of environmental science and policy in the Department of Earth and Planetary Sciences, and affiliated professor in the Environmental Science and Engineering Division of the John A. Paulson School of Engineering and Applied Science, all at Harvard University. From 2009 to 2017, he was the science advisor to President Obama and the Senate-confirmed director of the White House Office of Science and Technology Policy. His responsibilities included chairing the Arctic Executive Steering Committee, which coordinated Arctic programs and policies across 25 Federal agencies and offices.