Climate Change in the Arctic

Our polar regions are changing very rapidly

The Arctic fox is vulnerable to climate change through habitat loss and increased competition.
The Arctic fox is vulnerable to climate change through habitat loss and increased competition. Tom Walker/Photographer's Choice RF/Getty Images

We often think of the Arctic as a white, windswept place where it is always winter or nearly so with little hope for change. In reality, Arctic regions have been experiencing global climate change more dramatically than almost anywhere else on Earth. Average air temperatures in the Arctic have increase at twice the rate as on the rest of the globe. Just as it was globally, for many northern locations 2015 was a record warm year.

A Not-So-Frozen Record

The majority of the Arctic is comprised of sea water – the Arctic Ocean. So it is no surprise that the most dramatic manifestation of global warming is apparent in the patterns of sea ice dynamics. The extent, thickness, and age of sea ice have been decreasing in all parts of the Arctic.

The amount of ice that survives summer and remains by the time September rolls around (the so-called ice minimum) has been shrinking dramatically. In recent years a number of ships were allowed unfettered, ice-free navigation through the Northwest Passage, linking the Pacific and Atlantic Oceans through a northern route. In 2013, the first commercial cargo ship completed the historical trip. NOAA reports that in 2015 the maximum winter extent of sea ice was the lowest measured, but the record may not hold for very long: 2016 is lining up to win the dubious distinction of lowest recorded winter ice maximum.

Climate change is transforming our planet’s snow and ice in many different ways. If the trend continues, in a couple of decades summer heat will melt all of the Arctic sea ice, with the entire ice pack having to reform anew each autumn. The amount of multi-year ice (thick, solid ice pack made of several years’ worth of winter freezing, like layers in a cake) has decreased.

Over the 30 years between 1985 and 2015, the proportion of Arctic sea ice consisting of 4-year old ice decreased from 20% to a mere 3%. This is significant, as older ice is more resistant to winds and summer melting temperatures.

Compounding these startling statistics, at play is an insidious feedback loop called Artic Amplification. The light-colored ice reflects about 90% of the sunlight it receives (a phenomenon named albedo), but when that ice is absent the darker waters reflect only 10% of the light. As a result, the absorbed sunlight warms up water faster, melting yet more ice, and delaying ice formation in the fall.

Thawing Land

The physical consequences of climate change in the Arctic are not limited to sea water. Over land, much of the soil is permanently frozen (hence, the permafrost), but the situation is changing rapidly. Pockets of permafrost are thawing all over the north for a few weeks during the summer. The US Geological Survey warns that by 2100, 16 to 24% of the permafrost will have thawed. Here too a feedback loop is at play: as permafrost thaws, it releases stored carbon dioxide and methane, which are powerful greenhouse gases contributing further to climate change.

Thawing, Yes, But Also Burning...

As lightening grows more frequent in Arctic regions, and summers become warmer, tundra fires are also increasingly reported. These fires release large amounts of accumulated carbon and nitrogen, contributing further to climate change.

…And Slumping

Thawing ground is vulnerable to slumping and severe erosion, sending plumes of sediment in nearby streams and coastal areas. Native villages, oil and gas infrastructure, and roads are all routinely damaged by shifting ground. A report cites extra expenses totaling over $11 million for one northern Canada mining company forced to fly fuel instead of trucking it over now thawing roads.

These costs, however, are dwarfed by the global implications of permafrost, with the associated massive greenhouse gas release. One estimate puts the cost at an economy-disrupting $43 billion globally by the end of the century, according to University of Cambridge and University of Colorado researchers, in a study published in the journal Nature Climate Change.

Villages and oil facilities located on the shores of the Arctic Ocean face an additional threat: enhanced wave action. A combination of increasingly intense storms and large ice-free zones mean waves have more chance to build and propagate, pounding the thawing shores with damaging energy. Millions of dollars have been spent and many millions more will need to be allocated in order to build protective seawalls in northern coastal communities. For some communities, relocation is the only option. In 1997 the residents of the Yupik village of Newtok, Alaska, decided they needed to relocate. In fits and starts, they are in the process of moving a few miles inland. The US Government Accountability Office reports that 31 Alaskan villages are facing imminent threat from erosion and flooding, and that the residents of 12 of them are organizing to relocate.

A National Security Question?

The US Department of Defense has recognized that the consequences of global climate change in the Arctic have real military implications. As polar ice decreases in extent, new navigational passages open, providing new opportunities for commercial navigation and oil, gas, and mineral exploration. Many international and commercial interests are now vying for access in the Arctic, and in order to monitor the region and protect their interests, many nations (including Russia, Canada, and the United States) have deployed a greater military presence in the region.

Vulnerable Species

Increased wave action does not only affect humans. Storm surges and waves push tons of saltwater inland, destroying freshwater marshes and ponds that are habitat for breeding ducks and shorebirds. Globally, the most damaging threat to biodiversity is the loss of habitat, and it is no different in the Arctic. While salt water encroaches from the north, the tree line has been advancing north steadily, squeezing the tundra into an ever thinner ribbon capping the northern edge of the North American and Eurasian continents. The shrinking sea ice and tundra put a number of species at risk:

  • Polar bears rely on sea ice to travel and hunt ringed seal, their main prey. Reductions in available ice have made it more difficult for polar bears to survive energetically-challenging times, for example during the depths of winter and over the nearly ice-free summers.
  • Other marine mammals, like the walrus, narwhal, bowhead, and beluga whales are all relying on a food web and marine ecosystem deeply dependent on complex ice dynamics. The walrus and several seal species need the ice as a resting platform used between bouts of feeding.
  • The Arctic fox lives in coastal areas along the Arctic Ocean. It is threatened by changing ice patterns and fewer carnivores (polar bears) whose prey to scavenge. New competition for food is also arriving, as the red fox expands its range from the south.
  • Muskox and caribou require healthy, productive tundra vegetation for feeding, and that habitat is threatened as discussed above. In addition, warming trends encourage the production of pests like mosquitoes and other biting insects, and facilitate the propagation of parasites. These parasites are often brought north by other ungulates, like moose, which are expanding their range northward.
  • Many bird species use the tundra as nesting grounds, taking advantage of the brief summers to raise young. These birds include a large number of the shorebirds we encounter on beaches and mudflats across the world. Some of the most threatened bird species relying on Arctic tundra include spoon-billed sandpipers, emperor goose, Ross’ gull, and tundra bean goose. Other species, like the little auk and the ivory gull, are dependent on sea ice dynamics for food. Ivory gulls capture their prey right at the edge of the ice and during the nesting season they will shuttle between the ice edge and the nesting cliffs in search of food.