As climate stirs Arctic sea ice faster, pollution tags along

June 27, 2017

A warming climate is not just melting the Arctic's sea ice; it is stirring the remaining ice faster, increasing the odds that ice-rafted pollution will foul a neighboring country's waters, says a new study.

Declining sea ice is opening more of the Arctic Ocean to industrial development and resource extraction, raising concerns that oil spills and other pollution could endanger the region. The new study, which maps the movement of sea ice in the region, underscores the risk of contaminated sea ice drifting from the economic zone of one country to another's. Eight nations have exclusive economic zones off their Arctic coasts.

In the study, published this week in the journal Earth's Future, researchers at Columbia and McGill universities find that faster moving sea ice is responsible for exporting 1 million square kilometers of ice -- an area bigger than France and Germany combined -- from one nation to another each year. That's about a fifth of all sea ice formed.

"If you have a Deepwater Horizon-type spill where sea ice is forming, the oil can get into the ice and be transported to another country's waters," said study coauthor Stephanie Pfirman, a researcher at Barnard College and Columbia University's Lamont-Doherty Earth Observatory. "We show that what happens in your EEZ doesn't necessarily stay there."

As Arctic sea ice thins and retreats, the winds are pushing it faster and farther, allowing year-old ice to escape the summer-melt front, even as the front advances north. Using satellite images and GPS-tagged ice buoys, between 1988 and 2014 the researchers tracked 239,000 parcels of ice from their formation to their eventual demise. Consistent with earlier findings, they confirmed that ice floes have picked up their pace by about 14 percent each decade.

Partly due to this acceleration, they calculate that 21 percent of all ice, covering 1 million square kilometers, drifted beyond the exclusive economic zone, or EEZ, where it formed. The EEZ extends 200 miles off a country's coastline, but nations can extend their economic activities further if they can show that the sea bottom continues from their continental shelf.

Most Arctic sea ice forms in Russian waters, making Russia the region's top exporter of ice as well. Most Russian ice drifts into waters off Norway and Greenland. The United States is the region's second largest exporter, offloading most of its ice on Russia. The U.S., in turn, receives most of its imported ice from Canada.

"These regions are all connected," said the study's lead author, Robert Newton, an oceanographer at Lamont-Doherty. "If you have oil spills off one continental shelf, the ice will move that pollution to other nations, and to any wildlife refuges that we may create. If you're planning for conservation and stewardship you need to take a pan-arctic view."

The Arctic Ocean is expected to lose much of its summer sea ice by the 2030s as the region continues to warm twice as fast as the rest of the planet. The United States and its seven Arctic neighbors are already planning for the coming resource rush. The U.S. Geological Survey estimates that 13 percent of the world's undiscovered oil, and 30 percent of its natural gas, lie beneath the Arctic seafloor. Open waters in the summer are also expected to bring an uptick in freight shipping and tourist cruise ships.

The consequences of a spill could be enormous. In a worst-case scenario modeled earlier this year by study coauthor Bruno Tremblay and his colleagues, an oil spill at the end of the summer drilling season could be carried by sea ice 4,000 kilometers away, polluting up to 2 million square kilometers of ocean. The cleanup would be hampered by months of cold and near-complete darkness. By the following summer the contamination would reach multiple countries, they found.

As shrinking sea ice alters the habitat of polar bears, seals, whales and other Arctic wildlife, environmental groups, including most recently the International Union for the Conservation of Nature, have recommended creating a series of protected areas off the coasts of Canada and Greenland, where ice is projected to persist. The current study shows just how vulnerable downstream wildlife may be.

"We all know that pollution in a watershed ends up in lakes and rivers downstream," said Tremblay, who holds joint appointments at McGill University and Lamont-Doherty. "But I don't think the concept of an 'iceshed' is fully appreciated. The countries around the Arctic are all connected, so therefore we need to develop agreements that protect coastal waters where ice is formed."
The paper, "Increasing Transnational Sea Ice Exchange in a Changing Arctic Ocean," is available from the authors or the Columbia University press office.

Scientist contacts:

Robert Newton 845-365-8686

Stephanie Pfirman 845-365-8475

Bruno Tremblay

More information: Kim Martineau 212-854-5276

Lamont-Doherty Earth Observatory is Columbia University's home for Earth science research. Its scientists develop fundamental knowledge about the origin, evolution and future of the natural world, from the planet's deepest interior to the outer reaches of its atmosphere, on every continent and in every ocean, providing a rational basis for the difficult choices facing humanity. | @LamontEarth

The Earth Institute, Columbia University mobilizes the sciences, education and public policy to achieve a sustainable earth.

The Earth Institute at Columbia University

Related Sea Ice Articles from Brightsurf:

2020 Arctic sea ice minimum at second lowest on record
NASA and the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder shows that the 2020 minimum extent, which was likely reached on Sept.

Sea ice triggered the Little Ice Age, finds a new study
A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.

How much will polar ice sheets add to sea level rise?
Over 99% of terrestrial ice is bound up in the ice sheets covering Antarctic and Greenland.

A snapshot of melting Arctic sea ice during the summer of 2018
A study appearing July 29 in the journal Heliyon details the changes that occurred in the Arctic in September of 2018, a year when nearly 10 million kilometers of sea ice were lost throughout the summer.

Antarctic penguins happier with less sea ice
Researchers have been surprised to find that Adélie penguins in Antarctica prefer reduced sea-ice conditions, not just a little bit, but a lot.

Seasonal sea ice changes hold clues to controlling CO2 levels, ancient ice shows
New research has shed light on the role sea ice plays in managing atmospheric carbon dioxide levels.

Artificial intelligence could revolutionize sea ice warnings
Today, large resources are used to provide vessels in the polar seas with warnings about the spread of sea ice.

Antarctic sea ice loss explained in new study
Scientists have discovered that the summer sea ice in the Weddell Sea sector of Antarctica has decreased by one million square kilometres -- an area twice the size of Spain -- in the last five years, with implications for the marine ecosystem.

Antarctic sea-ice models improve for the next IPCC report
All the new coupled climate models project that the area of sea ice around Antarctica will decline by 2100, but the amount of loss varies considerably between the emissions scenarios.

Earth's glacial cycles enhanced by Antarctic sea-ice
A 784,000 year climate simulation suggests that Southern Ocean sea ice significantly reduces deep ocean ventilation to the atmosphere during glacial periods by reducing both atmospheric exposure of surface waters and vertical mixing of deep ocean waters; in a global carbon cycle model, these effects led to a 40 ppm reduction in atmospheric CO2 during glacial periods relative to pre-industrial level, suggesting how sea ice can drive carbon sequestration early within a glacial cycle.

Read More: Sea Ice News and Sea Ice Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to