[Vision2020] As Permafrost Thaws, Scientists Study the Risks

[Donovan Arnold]

What else is locked up in the thawing ice of the Arctic that might be released as the Earth warms? Does anyone know if it is possible for a virus or bacteria to be reintroduced into an animal, human, or plant population after all these years of being frozen? 
 
Donovan Arnold
 

________________________________
 From: Art Deco <deco at moscow.com>
To: Vision2020 at moscow.com 
Sent: Saturday, December 17, 2011 4:29 PM
Subject: [Vision2020] As Permafrost Thaws, Scientists Study the Risks
 

  

  
   



________________________________
 
December 16, 2011  
As Permafrost Thaws, Scientists Study 
the Risks 
By JUSTIN GILLIS 
FAIRBANKS, Alaska — A bubble rose through a hole in the surface of a frozen 
lake. It popped, followed by another, and another, as if a pot were somehow 
boiling in the icy depths.  
Every bursting bubble sent up a puff of methane, a powerful greenhouse gas 
generated beneath the lake from the decay of plant debris. These plants last saw 
the light of day 30,000 years ago and have been locked in a deep freeze — until 
now.  
“That’s a hot spot,” declared Katey M. Walter Anthony, a leading scientist in 
studying the escape of methane. A few minutes later, she leaned perilously over 
the edge of the ice, plunging a bottle into the water to grab a gas sample.  
It was another small clue for scientists struggling to understand one of the 
biggest looming mysteries about the future of the earth.  
Experts have long known that northern lands were a storehouse of frozen 
carbon, locked up in the form of leaves, roots and other organic matter trapped 
in icy soil — a mix that, when thawed, can produce methane and carbon dioxide, 
gases that trap heat and warm the planet. But they have been stunned in recent 
years to realize just how much organic debris is there.  
A recent estimate suggests that the perennially frozen ground known as 
permafrost, which underlies nearly a quarter of the Northern Hemisphere, 
contains twice as much carbon as the entire atmosphere.  
Temperatures are warming across much of that region, primarily, scientists 
believe, because of the rapid human release of greenhouse gases. Permafrost is 
warming, too. Some has already thawed, and other signs are emerging that the 
frozen carbon may be becoming unstable.  
“It’s like broccoli in your freezer,” said Kevin Schaefer, a scientist at the National Snow and Ice Data Center in Boulder, 
Colo. “As long as the broccoli stays in the freezer, it’s going to be O.K. But 
once you take it out of the freezer and put it in the fridge, it will thaw out 
and eventually decay.”  
If a substantial amount of the carbon should enter the atmosphere, it would 
intensify the planetary warming. An especially worrisome possibility is that a 
significant proportion will emerge not as carbon dioxide, the gas that usually 
forms when organic material breaks down, but as methane, produced when the 
breakdown occurs in lakes or wetlands. Methane is especially potent at trapping 
the sun’s heat, and the potential for large new methane emissions in the Arctic 
is one of the biggest wild cards in climate science.  
Scientists have declared that understanding the problem is a major priority. 
The United States Department of Energy and the European Union recently committed 
to new projects aimed at doing so, and NASA is considering a similar plan. But 
researchers say the money and people devoted to the issue are still minimal 
compared with the risk.  
For now, scientists have many more questions than answers. Preliminary 
computer analyses, made only recently, suggest that the Arctic and sub-Arctic 
regions could eventually become an annual source of carbon equal to 15 percent 
or so of today’s yearly emissions from human activities.  
But those calculations were deliberately cautious. A recent survey drew on the expertise of 41 permafrost scientists to offer more informal 
projections. They estimated that if human fossil-fuel burning remained high and 
the planet warmed sharply, the gases from permafrost could eventually equal 35 
percent of today’s annual human emissions.  
The experts also said that if humanity began getting its own emissions under 
control soon, the greenhouse gases emerging from permafrost could be kept to a 
much lower level, perhaps equivalent to 10 percent of today’s human emissions.  
Even at the low end, these numbers mean that the long-running international 
negotiations over greenhouse gases are likely to become more difficult, with 
less room for countries to continue burning large amounts of fossil fuels.  
In the minds of most experts, the chief worry is not that the carbon in the 
permafrost will break down quickly — typical estimates say that will take more 
than a century, perhaps several — but that once the decomposition starts, it 
will be impossible to stop.  
“Even if it’s 5 or 10 percent of today’s emissions, it’s exceptionally 
worrying, and 30 percent is humongous,” said Josep G. Canadell, a scientist in 
Australia who runs a global program to monitor greenhouse gases. “It will be a 
chronic source of emissions that will last hundreds of years.”  
A troubling trend has emerged recently: Wildfires are increasing across much 
of the north, and early research suggests that extensive burning could lead to a 
more rapid thaw of permafrost.  
Rise and Fall of Permafrost  
Standing on a bluff the other day, overlooking an immense river valley, A. 
David McGuire, a scientist from the University of Alaska, Fairbanks, sketched 
out two million years of the region’s history. It was the peculiar geology of 
western North America and eastern Siberia, he said, that caused so much plant 
debris to get locked in an ice box there.  
These areas were not covered in glaciers during the last ice age, but the 
climate was frigid, with powerful winds. The winds and rivers carried immense 
volumes of silt and dust that settled in the lowlands of Alaska and Siberia.  
A thin layer of this soil thawed on top during the summers and grasses grew, 
capturing carbon dioxide. In the bitter winters, grass roots, leaves and even 
animal parts froze before they could decompose. Layer after layer of permafrost 
built up.  
At the peak of the ice age, 20,000 years ago, the frozen ground was more 
extensive than today, stretching deep into parts of the lower 48 states that 
were not covered by ice sheets. Climate-change contrarians like to point to that 
history, contending that any melting of permafrost and ice sheets today is 
simply the tail end of the ice age.  
Citing permafrost temperatures for northern Alaska — which, though rising 
rapidly, remain well below freezing — an organization called the Center for the 
Study of Carbon Dioxide and Global Change claimed that permafrost is in “no more 
danger of being wiped out any time soon than it was in the days of our 
great-grandparents.”  
But mainstream scientists, while hoping the breakdown of permafrost will 
indeed be slow, reject that argument. They say the climate was reasonably stable 
for the past 10,000 years or so, during the period when human civilization 
arose. Now, as people burn immense amounts of carbon in the form of fossil 
fuels, the planet’s temperature is rising, and the Arctic is warming twice as 
fast. That, scientists say, puts the remaining permafrost deposits at risk.  
For several decades, researchers have been monitoring permafrost temperatures 
in hundreds of boreholes across the north. The temperatures have occasionally 
decreased in some regions for periods as long as a decade, but the overall trend 
has been a relentless rise, with temperatures now increasing fastest in the most 
northerly areas.  
Thawing has been most notable at the southern margins. Across huge areas, 
including much of central Alaska, permafrost is hovering just below the freezing 
point, and is expected to start thawing in earnest as soon as the 2020s. In 
northern Alaska and northern Siberia, where permafrost is at least 12 degrees 
Fahrenheit below freezing, experts say it should take longer.  
“Even in a greenhouse-warmed world, it will still get cold and dark in the 
Arctic in the winter,” said Mark Serreze, director of the snow and ice data 
center in Boulder.  
Scientists need better inventories of the ancient carbon. The best 
estimate so far was published in 2009 by a Canadian scientist, Charles 
Tarnocai, and some colleagues. They calculated that there was about 1.7 trillion 
tons of carbon in soils of the northern regions, about 88 percent of it locked 
in permafrost. That is about two and a half times the amount of carbon in the 
atmosphere.  
Philippe Ciais, a leading French scientist, wrote at the time that he was 
“stunned” by the estimate, a large upward revision from previous calculations.  
“If, in a warmer world, bacteria decompose organic soil matter faster, 
releasing carbon dioxide,” Dr. Ciais wrote, “this will set up a positive 
feedback loop, speeding up global 
warming.”  
Plumes of Methane  
Katey Walter Anthony had been told to hunt for methane, and she could not 
find it.  
As a young researcher at the University of Alaska, Fairbanks, she wanted to 
figure out how much of that gas was escaping from lakes in areas of permafrost 
thaw. She was doing field work in Siberia in 2000, scattering bubble traps 
around various lakes in the summer, but she got almost nothing.  
Then, that October, the lakes froze over. Plumes of methane that had been 
hard to spot on a choppy lake surface in summer suddenly became more visible.  
“I went out on the ice, this black ice, and it looked like the starry night 
sky,” Dr. Walter Anthony said. “You could see these bubble clusters everywhere. 
I realized — ‘aha!’ — this is where all the methane is.”  
When organic material comes out of the deep freeze, it is consumed by 
bacteria. If the material is well-aerated, bacteria that breathe oxygen will 
perform the breakdown, and the carbon will enter the air as carbon dioxide, the 
primary greenhouse gas. But in areas where oxygen is limited, like the bottom of 
a lake or wetland, a group of bacteria called methanogens will break down the 
organic material, and the carbon will emerge as methane.  
Scientists are worried about both gases. They believe that most of the carbon 
will emerge as carbon dioxide, with only a few percent of it being converted to 
methane. But because methane is such a potent greenhouse gas, the 41 experts in 
the recent survey predicted that it would trap about as much heat as the carbon 
dioxide would.  
Dr. Walter Anthony’s seminal discovery was that methane rose from lake 
bottoms not as diffuse leaks, as many scientists had long assumed, but in a 
handful of scattered, vigorous plumes, some of them capable of putting out many 
quarts of gas per day. In certain lakes they accounted for most of the emerging 
methane, but previous research had not taken them into consideration. That meant 
big upward revisions were probably needed in estimates of the amount of methane 
lakes might emit as permafrost thawed.  
Most of the lakes Dr. Walter Anthony studies were formed by a peculiar 
mechanism. Permafrost that is frozen hard supports the ground surface, almost 
the way a concrete pillar supports a building. But when thaw begins, the ground 
sometimes turns to mush and the entire land surface collapses into a low-lying 
area, known as a thermokarst. A lake or wetland can form there, with the dark 
surface of the water capturing the sun’s heat and causing still more permafrost 
to thaw nearby.  
Near thermokarst locations, trees often lean crazily because their roots are 
disturbed by the rapid changes in the underlying landscape, creating “drunken 
forests.” And the thawing, as it feeds on itself, frees up more and more ancient 
plant debris.  
One recent day, in 11-degree weather, Dr. Walter Anthony and an assistant, 
Amy Strohm, dragged equipment onto two frozen thermokarst lakes near Fairbanks. 
The fall had been unusually warm and the ice was thin, emitting thunderous 
cracks — but it held. In spots, methane bubbled so vigorously it had prevented 
the water from freezing. Dr. Walter Anthony, six months pregnant, bent over one 
plume to retrieve samples.  
“This is thinner ice than we like,” she said. “Don’t tell my mother-in-law! 
My own mother doesn’t know.”  
Dr. Walter Anthony had already run chemical tests on the methane from one of 
the lakes, dating the carbon molecules within the gas to 30,000 years ago. She 
has found carbon that old emerging at numerous spots around Fairbanks, and 
carbon as old as 43,000 years emerging from lakes in Siberia.  
“These grasses were food for mammoths during the end of the last ice age,” 
Dr. Walter Anthony said. “It was in the freezer for 30,000 to 40,000 years, and 
now the freezer door is open.”  
Scientists are not sure yet whether thermokarst lakes will become more common 
throughout the Arctic in a warming climate, a development that could greatly 
accelerate permafrost thaw and methane production. But they have already started 
to see increases in some regions, including northernmost Alaska.  
“We expect increased thermokarst activity could be a very strong effect, but 
we don’t really know,” said Guido Grosse, another scientist at the University of 
Alaska, Fairbanks. He is working with Dr. Walter Anthony on precision mapping of 
thermokarst lakes and methane seeps, in the hope that the team can ultimately 
use satellites and aerial photography to detect trends.  
With this kind of work still in the early stages, researchers are worried 
that the changes in the region may already be outrunning their ability to 
understand them, or to predict what will happen.  
When the Tundra Burns  
One day in 2007, on the plain in northern Alaska, a lightning strike set the 
tundra on fire.  
Historically, tundra, a landscape of lichens, mosses and delicate plants, was 
too damp to burn. But the climate in the area is warming and drying, and fires 
in both the tundra and forest regions of Alaska are increasing.  
The Anaktuvuk River fire burned about 400 square miles of tundra, and work on 
lake sediments showed that no 
fire of that scale had occurred in the region in at least 5,000 years.  
Scientists have calculated that the fire and its aftermath sent a huge pulse 
of carbon into the air — as much as would be emitted in two years by a city the 
size of Miami. Scientists say the fire thawed the upper layer of permafrost and 
set off what they fear will be permanent shifts in the landscape.  
Up to now, the Arctic has been absorbing carbon, on balance, and was once 
expected to keep doing so throughout this century. But recent analyses suggest 
that the permafrost thaw could turn the Arctic into a net source of carbon, 
possibly within a decade or two, and those studies did not account for fire.  
“I maintain that the fastest way you’re going to lose permafrost and release 
permafrost carbon to the atmosphere is increasing fire frequency,” said Michelle 
C. Mack, a University of Florida scientist who is studying 
the Anaktuvuk fire. “It’s a rapid and catastrophic way you could completely 
change everything.”  
The essential question scientists need to answer is whether the many factors 
they do not yet understand could speed the release of carbon from permafrost — 
or, possibly, slow it more than they expect.  
For instance, nutrients released from thawing permafrost could spur denser 
plant growth in the Arctic, and the plants would take up some carbon dioxide. 
Conversely, should fires like the one at Anaktuvuk River race across warming 
northern landscapes, immense amounts of organic material in vegetation, soils, 
peat deposits and thawed permafrost could burn.  
Edward A. G. Schuur, a University of Florida researcher who has done 
extensive field work in Alaska, is worried by the changes he already sees, 
including the discovery that carbon buried since before the dawn of civilization 
is now escaping.  
“To me, it’s a spine-tingling feeling, if it’s really old carbon that hasn’t 
been in the air for a long time, and now it’s entering the air,” Dr. Schuur 
said. “That’s the fingerprint of a major disruption, and we aren’t going to be 
able to turn it off someday.”   
 
  
  
______________________________ 
Wayne A. Fox
wayne.a.fox at gmail.com
 
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