The Arctic is climate change’s whipping post.
We’ve all seen the pictures of lonely polar bears floating on ice floes.
Or watched Greenland’s glaciers splinter into the sea.
Even those time-lapse models of coastal cities being swallowed by rising ocean water are now common illustrations of why climate change is especially associated with the Arctic.
But just when you thought you knew what to worry about, new research from the University of Alaska is proving that the Arctic could be more crucial to our survival than previously imagined.
In fact, the Arctic could go from being a buffer that protects us from climate change to being an ecosystem that actually contributes to it.
A quarter of all the world’s carbon - nearly 800 million metric tonnes - is stored in the Arctic ocean and the frozen land that surrounds it every year, said Daniel Hayes, a climate change researcher at the university’s Fairbanks campus.
It’s stored in dead organisms that don’t decompose because they’ve been frozen in permafrost since the last ice age, said Hayes.
But that permafrost is melting, releasing carbon directly into the atmosphere, he said.
This would reverse the Arctic’s role from carbon sink to carbon emitter.
“It could already be happening or it’s about to happen,” said Hayes, who worked with fellow scientist David McGuire on the research.
Hayes and McGuire had to stitch together a patchwork of different research to understand the precise role between carbon and the Arctic.
Scientists had already determined that permafrost is melting everywhere from Siberia to the Yukon.
The result is a puddle-riddled tundra where the ground lumps and slumps in unusual patterns, said Hayes.
“If you’ve ever seen a ‘drunken forest,’ where trees are tipping over to their side, that’s a sign of melting permafrost,” he said.
Measurements are taken by snapping aerial photographs of the land, he said.
And there’s been plenty of work done on how much carbon is stored in the permafrost, said Hayes. But because there are so many different methodologies, no one had bothered to get the bigger picture.
What Hayes and McGuire found was one of the world’s biggest carbon sinks.
Not only that, it’s a carbon sink stuck in a part of the world that’s heating up faster than the rest of the planet.
Fossil fuels trapped beneath the Earth’s surface, plant life and the soil itself are all known carbon sinks.
But until now, no one knew exactly how much carbon was frozen in permafrost.
The scientists revealed some other daunting challenges to conventional climate change thinking.
Methane, a poorly understood gas that’s found stuck beneath the ocean and in the atmosphere, could also become a major climate change culprit if the permafrost is left to melt.
When an animal or a plant rots, the presence of oxygen allows certain kinds of microbes to transform the organism’s carbon into carbon dioxide.
But when oxygen is scarce, a different kind of microbe goes to work, creating methane.
Because permafrost is melting beneath the ground, shutting off its carbon contents from the air, methane-spewing microbes might become prevalent in Arctic soil.
And because methane is 23 more times more effective at trapping heat in the atmosphere than carbon dioxide, permafrost melt could become a serious threat to the planet.
The Arctic already leaks about 50 million metric tonnes of methane into the atmosphere every year.
Methane bubbles appear in lakes where dead plants and leaves have been rotting beneath the water.
But the increase in methane production and the warming of the oceans could unleash “methane pulses” that no one can predict, said Hayes.
“It might not be a linear event,” he said.
Methane has been increasing in the atmosphere for years, he said.
But in 2007, scientists recorded a major methane pulse.
“They believe it came from the high Arctic,” he said.
Russia’s high Arctic region is also feared to be a major methane storage site, and research there is patchy, said Hayes.
“It’s just such a big area of land,” he said.
Another big unknown are the positive and negative feedbacks of melting permafrost.
Cold water can store more carbon dioxide, said Hayes, so as the Arctic warms, the ocean can’t do it’s regular carbon sink job.
A reverse effect could be the increase in Arctic Ocean sea life, because bigger algae and phytoplankton populations would suck in more carbon dioxide through photosynthesis.
Similarly, growing seasons in the Arctic could increase, releasing more oxygen, said Hayes.
“It’s a question of which one is beating the other,” he said.
“But it looks like the positive feedbacks might be stronger.”
Contact James Munson at
jamesm@yukon-news.com