Our first stop during our months of reporting on climate change in the high north, wasn’t in the Arctic – but it was an important visit. Permafrost is becoming more and more critical to greenhouse gases filtering into the atmosphere. We went to the permafrost research tunnel in Fairbanks, Alaska to learn more.
Permafrost is exactly what it sounds like: ground that is supposed to be permanently frozen. The tunnel is a working lab, and almost seems like a small natural history museum.
The tunnel itself is maintained by the U.S. Army Corps of Engineers, and they are the gatekeepers for allowing researchers (and journalists) in.
In simple terms, as the Arctic and near-Arctic areas warm, permafrost starts to thaw. That’s bad news for a number of reasons. For one, sinkholes are popping up all over Alaska, and throughout the Arctic globally, as ice-wedges beneath the surface melt. So, homes, businesses, roads, and pipelines are in danger of being swallowed as the permafrost surrenders to a warmer climate and the ground can no longer support the same weight.
The tunnel was constructed more than half a century ago. At the height of the Cold War (ironic right?), the United States wanted to find out if they could tunnel into frozen earth should the Soviets attack Alaska and America needed a place to store weapons.
While digging the tunnel, crews unearthed an array of prehistoric bones — mammoths, bison, musk ox, and other animals are still protruding from the walls. Fascinating stuff.
But in the last decade, researchers such as Vladimir Romanovsky are uncovering different, more important findings. Romanovsky came to the U.S. from the former Soviet Union around 1990 to study permafrost. By his own account, it was really a pretty boring field at the time.
Permafrost wasn’t supposed to thaw, and for the most part it didn’t.
But climate change altered all that. Now the tunnel has scars from where researchers have pried core samples from the earth, trying to understand the consequences of thawing permafrost.
Aside from an obvious downside of buildings being consumed by the earth when permafrost melts, there is a hidden concern. Permafrost has locked in twice as much carbon dioxide and methane in the frozen grass and turf as there is in the atmosphere. So do the math: if permafrost continues to thaw, more greenhouse gases will be released into the air, feeding the harsh cycle of rising temperatures.
Permafrost is important to people of the north. Heavy construction needs to be done in the winter when the ground is frozen solid. So visit Deadhorse, Alaska — the head of the Trans-Alaska pipeline — and you can see massive machines slowly plodding on permafrost. In other areas, indigenous populations have dug into the permafrost to create natural refrigeration to store whale, walrus, and other subsistence kills.
Researchers are worried about the future. Unless governments can find a way to get a handle on climate change, Romanovsky worries that permafrost in the Arctic, long thought invulnerable to climate change, could thaw completely in the next 100 years.
Another melting concern is Arctic sea ice, and how much less of it there is
Arctic sea ice is frozen seawater. At the end of the summer melt, sea ice is at its minimum extent, and after the winter freeze, it’s at its maximum.
Covered with snow for most of the year, sea ice reflects sunlight away from the ocean. This helps keep temperatures cool in the Arctic. When it melts, sunlight (and heat) is absorbed into the water, and the ocean gets warmer.
Most sea ice forms in the winter, and some of it melts away in the summer. But this cycle has been changing: scientists have found that the extent of sea ice has declined dramatically over the past three decades. Less sea ice means more open ocean, which in turn means a warming Arctic. As the Arctic and Antarctic help moderate global climate, a change there can cause changes elsewhere in the world.
On average, minimum sea ice extent in the Arctic was 6.5 million square kilometers (2.5 million square miles) from 1980 to 2010. The record low was set in 2012, when there was only 3.62 million sq/km (1.39 million sq/m). The record high of 7.87 million square kilometers (3.03 million square miles) was set in 1996.
But in 2015, sea ice extent was nearly a third below the average: 4.63 million square kilometers (1.78 million square miles).
“Ten years ago this would have been an astonishing summer of ice melt,” National Snow and Ice data Center lead scientist Ted Scambos said in a press release. “Now it is just another season in a decade of low years.”
According to the Center, the melt’s pace picked up rapidly in July, as temperatures across the Arctic hit the second highest on record.
“What we have seen this summer reinforces our conclusions that Arctic sea ice extent is in a long-term decline and that we are headed for a seasonally ice-free ocean,” NSIDC director Mark Serreze said.