Arctic's Summer Sea Ice Could Be Gone in 20 Years

Say goodbye to dreams of standing at the top of the world, for you may soon have to swim. A report published last week by the Arctic Monitoring and Assessment Programme suggests that the Arctic may be ice-free in summer within twenty years. The 90 authors of the rigorously peer-reviewed AMAP report state, “Extrapolations of recent observed data suggest a largely ice-free summer ocean by the late 2030s, which is earlier than projected by most climate models.”

This timeframe is also much sooner than AMAP reports from the early 2000s predicted. An executive summary published in 2004, just 13 years ago, projected near total loss of summer sea ice by the end of this century. Now, with summer sea ice forecasted to be gone by the late 2030s, that projection has been sped up about 70 years. The faster pace of Arctic climate change means that there is even less time for communities, nations, and international organizations to design and implement adaptation policies. Where we once might have had another eight decades or so to prepare for an ice-free Arctic, we now may have only two decades. Importantly, extrapolations from recent data rather than models are what indicate that society has hit the fast-forward button on Arctic climate change. 

The AMAP report executive summary, which is written with policy makers in mind, has six key findings. They are: 

- The Arctic climate is shifting to a new state.
- Arctic climate change is continuing at a rapid pace.
- Warming that is already “locked in” to the climate change means that climate change will continue at least through mid-century.
- Reducing greenhouse gas emissions, however, can stabilize change after 2050.
- Mitigation and adaptation policies can limit vulnerabilities.
- Putting these in place requires a solid understanding of Arctic climate change.

In other words, the takeaway message appears to be: Arctic climate change is drastic, but it can be stabilized if we continue to do good scientific research and implement science-based policy. Of course, as the report also notes, traditional ecological knowledge should also inform decision making.

By the numbers

You could read the report and learn that the Arctic was warmer from 2011-2015 than at any point since record keeping began in 1900. Or that sea ice thickness declined by 65% between 1975 and 2012. Or that Greenland lost more than 20 square miles of ice each year from 2011-2014, nearly twice as much as was lost between 2003 and 2008. These numbers are shocking, but perhaps it’s easier to conceptualize Arctic change in terms of how much else it affects, both locally and globally. Below are a few snapshots of what all that melting sea ice means for the world at large.

Local impacts

Hunting opportunities will be curtailed with the loss of summer sea ice. As a recent publication in Biology Letters based on interviews with 11 coastal hunters from the Bering Sea to the Beaufort Sea described, hunting will become harder and more dangerous. Sea ice limits wave action, so without it, open water navigation actually becomes more precarious. Species like walruses and seals also hang around the ice, so hunters will have to travel farther out as sea ice retreats – and who knows where these animals will go once there is no more summer sea ice (perhaps they may instead haul out on land). 

An ice dam on the Greenland ice sheet. August 2014. Photo: Mia Bennett

Unlike Arctic summer sea ice, the Greenland Ice Sheet should stick around for a lot longer. Studies have found that it would take at least 1,000 years of sustained temperatures 3°C higher than average for it to completely melt away. Still, current levels of melting on the world’s largest island can contribute significantly to sea level rise. The 2013 Intergovernmental Panel on Climate Change (IPCC) report predicted that Greenland’s melting would contribute 9 inches to sea level rise by 2100. Eric Rignot, professor of Earth system science at UC Irvine, believes that could be an underestimate. 

And what would happen if and when the ice sheet were to disappear? First, there would be about 23 feet of sea level rise. Second, an older, deeply sobering study called, “Climatic Impact of a Greenland Deglaciation and Its Possible Irreversibility,” came to a very finite conclusion. If the Greenland ice sheet were to completely melt away, the authors found, its disappearance would be “irreversible” even if preindustrial climate conditions were reestablished afterwards. In other words, once it’s gone, it’s gone. 

Global ramifications

Boreal forests are literally “breaking apart” as the permafrost beneath them thaws. Apart from the oceans, they are the world’s largest biome, stretching across Alaska, Canada, the Nordic countries, and Russia, where they are called taiga. The increased rate of forest fires is also burning through big stands of trees. It’s thought that climate change was behind the devastating forest fires that engulfed the boreal boom town of Fort McMurray, Alberta last spring, painfully revealing the human and economic impacts of rapid northern climate change. 

This is what happens to trees when the permafrost beneath them thaws and refreezes year after year. Photo: Mia Bennett, Northwest Territories, Canada. June 2016.

Arctic warming could alter the Southeast Asian monsoon, possibly leading to up to 70% less rain in India and Southeast Asia during the summer monsoon season. As the Arctic gets warmer and wetter, parts of the world that already are suffering water shortages may be even more hard up for H2O. 

Is there still hope?

The AMAP report’s determination that Arctic climate change is already “locked in” through 2050 may sound like mitigation efforts are futile. But they are not. The authors conclude, “Climate models show that reducing greenhouse gas emissions and stabilizing concentrations, under a scenario roughly consistent with the Paris Agreement, could stabilize the further loss of snow cover and permafrost after mid-century.” All the more reason, then, for the United States not to renege on the landmark global climate agreement. 

The outlook for the Paris Agreement remains grim, however. At a campaign-style rally in Pennsylvania last night marking his first 100 days in office, President Donald Trump promised (threatened?), “I’ll be making a big decision on the Paris accord over the next two weeks, and we’ll see what happens.” It’s unclear which way the president will swing given the divisions between his advisors and cabinet members on the matter. But if the U.S. pulls out the rug from under the Paris Agreement, any chance we have to stabilize Arctic warming will likely evaporate.