Web Earth Online

In the news,

"SAN FRANCISCO — The target set by nations in global warming talks won't prevent the devastating effects of global warming, according to climate scientist James Hansen, director of NASA's Goddard Institute for Space Studies.

The history of ancient climate changes, which occurred over millions of years in the planet's history as it moved in and out of ice ages, offers the best insight into how humans' greenhouse gas emissions will alter the planet, Hansen said here today (Dec. 6) at the annual American Geophysical Union (AGU) meeting. And his research suggests the climate is more sensitive to greenhouse gas emissions than had been suspected.

"What the paleoclimate record tells us is that the dangerous level of global warming is less than what we thought a few years ago," Hansen said. "The target that has been talked about in international negotiations for 2 degrees of warming is actually a prescription for long-term disaster."

Hansen is referring to the goal set by climate negotiators in Copenhagen in 2009 to keep the increase in the average global temperature below 3.6 degrees Fahrenheit (2 degrees Celsius). That cap was put in place as a means to avoid the most devastating effects of global warming. [How 2 Degrees Will Change Earth]

However, signs of changes that will exacerbate the situation, such as the loss of ice sheets that will raise sea level and change how much sunlight is reflected off the planet's surface, are already appearing, according to Hansen.

Two degrees of warming will lead to an ice-free Arctic and sea-level rise in the tens of meters, Hansen told LiveScience. "We can't say how long that will take, [but]it’s clear it's a different planet."

Climate negotiators, currently gathered in Durban, South Africa, are working with that 2-degree goal, trying to figure out ways to meet it.

If greenhouse gas emissions continue to rise unabated, the Earth's temperature is expected to increase by about 5.4 degrees F (3 degrees C) thanks to short-term effects, such as an increase in water vapor in the atmosphere and changes in cloud cover, which will amplify or weaken the temperature increase. But this is only a small piece of the warming that is expected, according to Hansen's research.

Some fast-feedback effects show up within decades, and some of these show up only when other parts of the system, particularly the oceans, which warm slowly, catch up with atmospheric warming. This can take centuries.

There are also slow-feedback effects that are expected to amplify global warming, particularly, the melting of ice sheets. The darker ground beneath the ice and the meltwater that pools on top of it absorbs more sunlight, warming the planet even more.

It's difficult to project how long the effects will take to set in, because, in the history of Earth's climate, the level of carbon dioxide in the atmosphere has never risen as quickly as it is now.

Because there is evidence that ice sheets are losing mass, the planet is already facing these powerful feedbacks, making the goal of reducing greenhouse gas emissions to a point that prevents warming of 3.6 degrees F (2 degrees C) insufficient, said Hansen and his colleagues Ken Caldeira of Stanford University and Eelco Rohling of the University of Southampton in England said during their presentation."

"Two degrees of warming will lead to an ice-free Arctic and sea-level rise in the tens of meters, Hansen told LiveScience. "We can't say how long that will take, [but]it’s clear it's a different planet."
Ice free Arctic? Sea-level rise? That sounds bad!

First a few Facts:
Humans create carbon dioxide most notably through emissions burning fossil fuels.
Carbon dioxide is a green house gas.
The green house effect is real.
Therefore humans are contributing to global warming.

Now that these basic facts have been realized we can move on to the question of, how much effect are humans having on warming?

I would refer to ice core data for one insight on this question.
Scientist have taken ice core samples in Antarctica that go back millions of years.
Ice cores build up in layers like rings on a tree where each ring is a year of time.
Trapped in these samples are the air that goes back millions of years.
Scientist have measured the amount of carbon dioxide that was in the air at those times.
They found that the most carbon dioxide recorded going back that far was 290 parts of carbon dioxide per million.
Today carbon dioxide levels are 390 parts per million. see http://co2now.org/
390+ parts per million of carbon dioxide is not a normal natural cycle, rather it is way outside of the range of what would be considered normal over millions of years.
Humans have pushed carbon dioxide levels WAY outside of anything that could be called normal levels.

I have heard that Carbon Dioxide takes hundreds of years to dissipate.
So you are talking about sort of stopping Carbon Dioxide levels completely, but remember that we continue to increase the levels, not decrease the levels.

Compressed air is just a stored form of energy. Sort of like a battery but with air jammed into a cylinder under high pressure which can later be released to move or power a car for example.
So the question is, what energy source is used to compress the air (thereby storing energy).
If the energy used to compress the air is clean (like say solar energy was used to compress the air), then it can be a totally clean energy cycle.
And you are right, then in this case it could be totally clean with zero emissions.

There are many issues being discussed concerning side effects of warming.
Rising water levels is just one.
This week I heard a show on the radio which talked about the fact that scientist have been way too conservative on the amount of melting that is going on.
So sea levels are rising much faster than predicted.
Right now they think 100 million people will be displaced from their homes and cities by the end of this century by rising water levels.

This is a really big topic when you start trying to consider all the possible side effects.
Predicting rising temperatures is one thing the climatologists are doing.
Predicting all the side effects of rising temperatures seems to get even more complex.
I think that there is the possibility of something called runaway feedback that could occur in the environment.
For example, permafrost up north is starting to melt, when it does, it releases methane, methane is an even more powerful green house gas with a quicker dissipation time than carbon dioxide, and the methane release causes more warming, which causes the permafrost to melt even more, which causes even more methane to release, which causes even more permafrost to melt, which causes ... well you get the idea, that is run away feedback.
There are other climate systems that could be impacted like this (look up the heat pumps which run in the Atlantic ocean driving the gulf stream and what might happen if too much fresh water melts changing the salinity of the ocean (saltiness of the ocean), causing these heat pumps to shut down, which could lead to slamming us back into an ice age).

It is liking we are performing this experiment on a global scale.
Who approved this experiment?
What are the risks?

Alexander wrote:How interesting. So, if we found another alternative, such as maybe just compressed air (I remember my father telling me about this), will the Earth be able to renew itself of the massive levels of carbon dioxide, or will it be so bad that it either ends up like Terra Nova where you can't breathe outside your own home or will we have to help our Earth back to its natural state?
I'm guessing that may be the question for now. And the answer depends on time and time as in when it will stop and how much of it will stop. Another thing to consider would be if the alternative was cheaper and more effective...
Thank you for using facts and giving me a non-opinionated answer.

In the news,

"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.

Josh Haner/The New York Times
In an Alaskan lake, bubbles of methane, a potent greenhouse gas, collect beneath the ice. More Photos »
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.”
Temperature Rising

Trouble in the Arctic

Articles in this series are focusing on the central arguments in the climate debate and examining the evidence for global warming and its consequences.
Previous Articles in the Series »
Multimedia

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.
Temperature Rising

Trouble in the Arctic

Articles in this series are focusing on the central arguments in the climate debate and examining the evidence for global warming and its consequences.
Previous Articles in the Series »
Multimedia

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.
Temperature Rising

Trouble in the Arctic

Articles in this series are focusing on the central arguments in the climate debate and examining the evidence for global warming and its consequences.
Previous Articles in the Series »
Multimedia

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.” "

A response to the New York Times article,

For pictures and full article see :
http://thinkprogress.org/romm/2011/12/1 ... ory-right/

"The good news: The best NOAA analysis “suggests we have not yet activated strong climate feedbacks from permafrost and CH4 hydrates.” Climate Progress first reported that finding 2 years ago. The lead author of that work confirms to CP it still remains true — despite the fact that methane levels have been rising for the past 5 years after a decade of little growth.
The bad news: Leading experts at NOAA, the National Snow and Ice Data Center and around the world now expect the permafrost to become a major source of atmospheric carbon in the next few decades (see “NSIDC/NOAA: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100″ and “Nature: Climate Experts Warn Thawing Permafrost Could Cause 2.5 Times the Warming of Deforestation!“)
NY Times science reporter Justin Gillis has just published an excellent overview article, “As Permafrost Thaws, Scientists Study the Risks.” The piece makes clear we may be near a tipping point, citing University of Alaska scientist Vladimir Romanovsky:
In northern Alaska, Dr. Romanovsky said, permafrost is warming rapidly but is still quite cold. In the central part of the state, much of it is hovering just below the freezing point and may be no more than a decade or two from widespread thawing.
That thawing is of great concern because the permafrost contains a staggering amount of carbon, as Nature reported:
The latest estimate is that some 18.8 million square kilometres of northern soils hold about 1,700 billion tonnes of organic carbon4 — the remains of plants and animals that have been accumulating in the soil over thousands of years. That is about four times more than all the carbon emitted by human activity in modern times and twice as much as is present in the atmosphere now.
The permafrost carbon thus represents a dangerous amplifying feedback or vicious cycle whereby warming leads to accelerated emissions, which leads to further warming. And that could lead to a point of no return, as Gillis reports:
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….
That’s especially true since sea ice loss in the Arctic is happening faster than every major climate model projected — and accelerated Arctic warming and permafrost loss was linked to ice loss in a 2008 study by leading tundra experts, “Accelerated Arctic land warming and permafrost degradation during rapid sea ice loss“:
We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km inland and is apparent throughout most of the year, peaking in autumn. Idealized experiments using the Community Land Model, with improved permafrost dynamics, indicate that an accelerated warming period substantially increases ground heat accumulation. Enhanced heat accumulation leads to rapid degradation of warm permafrost and may increase the vulnerability of colder permafrost to degradation under continued warming. Taken together, these results imply a link between rapid sea ice loss and permafrost health.
And, of course, recent analysis suggests that our current “no policy” approach to climate will lead to staggering Arctic warming this century (see M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20°F).
So by any objective measure, the recent science and observations of the permafrost are increasingly worrisome.
While the NY Times‘ Gillis gets this right in the print edition, NYT blogger Andy Revkin asserts in a post published 3 days earlier focused on sea-based methane hydrates, “There’s an entirely different set of questions, also with relatively reassuring answers, about the vast amounts of methane locked in permafrost on land.” Not!
The NYT would seem to be schizophrenic on this crucial topic, but Gillis clearly has the story right and it isn’t reassuring at all.
Indeed, Gillis adds some new reporting that is very un-reassuring:
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.
Let’s look at the highlights of the important Gillis piece before returning to the sea-based issue:
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.”
Are you relatively reassured yet?
The article has a nice graphic (click to enlarge).
When the Tundra Burns
Gillis has some important reporting on a related amplifying feedback
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.”
Gillis points outs:
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.
I’ve written about the peat issue recently (see “Stunning Peatlands Amplifying Feedback — Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold: “Drying of northern wetlands has led to much more severe peatland wildfires and nine times as much carbon released into the atmosphere, according to new research“).
I would add that denser plant growth in the Arctic might not actually be such a good thing — because of reduced snow cover and albedo (reflectivity). According to a 2008 Science article: “Continuation of current trends in shrub and tree expansion could further amplify [Arctic] atmospheric heating 2-7 times.” The point is that if you convert a white landscape to a boreal forest, the surface suddenly starts collecting a lot more solar energy (see “Tundra 3: Forests and fires foster feedbacks“).
The point is that if you convert a white landscape to a boreal forest, the surface suddenly starts collecting a lot more solar energy.
And then we have the study, “Frequent Fires in Ancient Shrub Tundra: Implications of Paleorecords for Arctic Environmental Change,” which finds:
… greater fire activity will likely accompany temperature-related increases in shrub-dominated tundra predicted for the 21st century and beyond. Increased tundra burning will have broad impacts on physical and biological systems as well as on land-atmosphere interactions in the Arctic, including the potential to release stored organic carbon to the atmosphere.
The concern is not so much the direct emissions from burning tundra. As the article concludes: “studies of modern tundra fires suggest the possibility for both short- and long-term impacts from increased summer soil temperatures and moisture levels from altered surface albedo and roughness, and the release soil carbon through increased permafrost thaw depths and the consumption of the organic layer.”
Gillis ends his piece:
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.”
There is nothing reassuring in the least about recent permafrost research and observation.
Methane Emissions
It is widely believe that some of the carbon locked away in the tundra will be released as methane, a very potent greenhouse gas. Gillis notes:
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.
Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times to 100 times as potent over 20 years! The new Nature study found:
Across all the warming scenarios, we project that most of the released carbon will be in the form of CO2, with only about 2.7% in the form of CH4. However, because CH4 has a higher global-warming potential, almost half the effect of future permafrost-zone carbon emissions on climate forcing is likely to be from CH4. That is roughly consistent with the tens of billions of tonnes of CH4 thought to have come from oxygen-limited environments in northern ecosystems after the end of the last glacial period.
And because of the much higher warming impact of methane over shorter time frames, even this low percentage level of methane means that over a 20 year period, the warming from CH4 will actually be higher than that of CO2.
Because methane is so potent and because of the recent literature on the Arctic warming and tundra melt, many have wondered whether the Arctic is responsible for the recent resurgence in global methane levels. Here is the latest data from The NOAA Annual Greenhouse Gas Index:

As you can see, methane levels are on the march again after almost a decade.
Back in 2009, I wrote about a NOAA-led study, Dlugokencky et al., “Observational constraints on recent increases in the atmospheric CH4 burden” (subs. req’d, NOAA online news story here), which found:
The most likely drivers of the CH4 anomalies observed during 2007 and 2008 are anomalously high temperatures in the Arctic and greater than average precipitation in the tropics. Near-zero CH4 growth in the Arctic during 2008 suggests we have not yet activated strong climate feedbacks from permafrost and CH4 hydrates.
But then we seemed to get some reports that suggested that Arctic methane hydrates could be a source of the continuing surge (see my March 2010 post here). The lead author of an NSF-funded study said on the Eastern Siberian Arctic Shelf said, “Our concern is that the subsea permafrost has been showing signs of destabilization already. If it further destabilizes, the methane emissions may not be teragrams, it would be significantly larger.” The NSF warned, ““Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.”
And then this month, we had the UK’s Independent writing a story on the work of Russian scientist Igor Semiletov of the International Arctic Research Centre at the University of Alaska Fairbank, “Shock As Retreat of Arctic Sea Ice Releases Deadly Methane Gas Levels.”
But Dlugokencky emails that his work through 2010 confirms:
There is no evidence from our atmospheric measurements that there has been a significant increase in emissions during the past 20 years from natural methane sources in the Arctic so far.
And, as Revkin notes, a new study finds, “Siberian shelf methane emissions not tied to modern warming” (subs. req’d). That study suggests the offshore methane hydrates are unlikely to be a big contributor to methane emissions this century.
I tend to think all bets are off after 2100 if we are idiotic enough to stay on our current emissions path (see Science stunner — On our current emissions path, CO2 levels in 2100 will hit levels last seen when the Earth was 29°F (16°C) hotter).
I wanted to probe further, so I interviewed Stephen Wofsy of Harvard University. He has been flying on NSF’s research plane HIAPER (for High Performance Instrumented Airborne Platform for Environmental Research) as part of the HIPPO (for HIAPER Pole-to-Pole Observations) pollution mapping program.
Science News had written this back in September:
Something too new to fully understand (although a report on it is being prepared for publication), Wofsy says, is a finding of notable concentrations of methane in the Arctic’s atmosphere that trace back to the sea.
“Oceanographers have known for some time that there is production of methane in surface waters of the Arctic,” he says, but “it’s never been observed in the atmosphere.” Those oceanographic data, he says, suggest a source for this methane other than sediments or the melting of icy gas hydrates.
The phenomenon also appears very widespread. “We observed that the ocean surface releases methane to the atmosphere all over the whole of the Arctic Ocean,” Wofsy says.
Climate scientists have been concerned about whether the Arctic Ocean’s loss of summer ice cover might lead, through some feedback mechanisms, to boosting the release of methane. Concludes Wofsy: Thanks to HIPPO, “This hypothesized feedback has been observed for the first time.” And there are hints, he adds, that methane’s source may be something other than melting of gas hydrates.
Tantalizing, no?
According to Wofsy, HIPPO saw significant methane fluxes over the Arctic ocean away from the shore — but this “wasn’t seen where the ice is solid.” He thinks it is probably due to algae munching anaerobically. And he thinks that the retreat of the ice increases the productivity of the algae and allows more of the methane to escape.
He doesn’t think this will “blow the world up,” but he does think it is a significant effect and could increase as the ice retreats. He’ll be describing his findings in more detail in a forthcoming Journal article.
BOTTOM LINE
The key conclusion remains unchanged from my October 2009 post, “Is it just too damn late?“ We have not crossed a tipping point or point of no return with methane releases in the Arctic. It’s not too late to avert the worst impacts of human-caused global warming.
But what we now know that wasn’t so clear back then is that the best science and the leading scientists say we are likely to see large releases of carbon from the permafrost this century – particularly if we don’t aggressively reduce greenhouse gas emissions starting ASAP.
The stunning conclusion of the NOAA/NSIDC paper was:
The thaw and release of carbon currently frozen in permafrost will increase atmospheric CO2 concentrations and amplify surface warming to initiate a positive permafrost carbon feedback (PCF) on climate…. [Our] estimate may be low because it does not account for amplified surface warming due to the PCF itself….
We predict that the PCF will change the arctic from a carbon sink to a source after the mid-2020s and is strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible and accounting for the PCF will require larger reductions in fossil fuel emissions to reach a target atmospheric CO2 concentration.
The Nature article concludes:
Our group’s estimate for carbon release under the lowest warming scenario, although still quite sizeable, is about one-third of that predicted under the strongest warming scenario.
… our survey outlines the additional risk to society caused by thawing of the frozen north, and underscores the urgent need to reduce atmospheric emissions from fossil-fuel use and deforestation. This will help to keep permafrost carbon frozen in the ground.
The only thing recent research on the Arctic reassures us about is the urgent need to cut emissions sharply and quickly."

I know the two articles above are long, but they address with some detail the concern of runaway feedback in the environment due to global warming.