FAIRBANKS, Alaska (AP) - Ounce for ounce, methane has an effect on global
warming more than 30 times more potent than carbon dioxide, and it’s leaking
from the Arctic Ocean at an alarming rate, according to new research by
scientists at the University of Alaska Fairbanks.
Their article, which appeared Sunday in the peer-reviewed journal Nature
Geoscience, states that the Arctic Ocean is releasing methane at a rate more
than twice what scientific models had previously anticipated.
Natalia Shakhova and Igor Semiletov at UAF’s International Arctic Research
Center have spent more than a decade researching the Arctic’s greenhouse gas
emissions, along with scientists from Russia, Europe and the Lower 48.
Shakhova, the lead author of the most recent report, said the methane
release rate likely is even greater than their paper describes.
“We decided to be as conservative as possible,” Shakhova said. “We’re
actually talking the top of the iceberg.”
The researchers worked along the continental shelf off the northern coast of
eastern Russia - the East Siberian Arctic Shelf, which is underlain by
Much like the now-submerged Beringia, the land bridge that once connected
Alaska to Russia, the East Siberian Arctic Shelf was dry land until around
7,000 to 15,000 years ago, when it flooded and became part of the Arctic
Ocean. During that time on dry land, the shelf developed a layer of
permafrost that is now in danger of melting away and releasing vast amounts
of greenhouse gases.
Past studies in Alaska and other circumpolar regions have stated that the
boreal forests covering much of the world’s Arctic and sub-Arctic dry land
contain more than 30 percent of the world’s stored carbon. This carbon is
protected from atmospheric release in large part by the permafrost layer.
The submerged East Siberian Arctic Shelf contains much of the same stored
carbon as the dry-land tundra just to its south, but it also contains at
least 17 teragrams of methane, the study states. A teragram is equal to 1
Those carbon stores are similarly protected by the layer of sub-sea
permafrost, but that permafrost is teetering on the brink of disappearing.
Core samples taken of the sub-sea permafrost by Shakhova and her peers
showed temperatures near the freezing mark, around 30 to 32 degrees. Both
the top and lower layers of sediment had already thawed.
Some climate modelers had previously suggested the sub-sea permafrost would
not thaw for 5,000 to 7,000 years, but according to Shakhova’s team, the
data gathered from the actual shelf shows the process is happening on a much
more rapid timescale.
“What we’re observing right now is much faster than what we anticipated and
much faster than what was modeled,” Shakhova said.
This revelation should be a cause for alarm, Shakhova said.
“Absolutely. We think so,” she said. “We should not only just worry. We
Climate scientists have constructed what they call a carbon budget to
determine how much carbon-based gas, such as methane and carbon dioxide, is
being released into the atmosphere. Many climate change projections are
based on this budget.
The consensus carbon budget estimates that more than half of carbon
emissions are human-caused, but these estimates vastly underestimate the
amount of carbon stored in the Arctic shelves, Shakhova said.
“I believe strongly the Arctic sources are understated and need to be paid
more attention,” Shakhova said.
The UAF researchers also concluded the Arctic methane release creates a
positive feedback loop. As temperatures increase, more methane is released
and as more methane is released temperatures increase.
In addition, storms throughout the Arctic Ocean have increased in the past
decade, according to multiple studies cited by the UAF team. These storms
speed up the methane release just as shaking a soda causes the carbonation
to rise more rapidly to the top and escape.
In the end, the Arctic and sub-Arctic regions may have the most to lose.
“When something is warming, when warming occurs, what, do you think, part of
the globe will be affected first?” Shakhova said. “The Arctic is warming
twice as fast as the rest of the globe. ... This is what affects the number
of cyclones. This is what affects the sea ice, which is shrinking.”
Shakhova didn’t want to dwell on predictions or possible outcomes from such
rising temperatures. What she wanted to see, she said, was more primary
research in the Arctic itself to determine what is happening. “Our study is
not about being depressing,” Shakhova said. “It’s about knowledge, no matter
if you like it or not.”