Awakening the Sleeping Giants

Over many millenia, carbon has been trapped in the Arctic, both in the terrestrial permafrost in Northern Canada and Russia and in methane hydrates capped by subsea permafrost in the East Siberian Arctic Shelf. The stable frozen conditions of the Artic have essentially kept this vast store safely locked away. All that is about to change, however as the Arctic is the fastest warming region on the planet today, warming twice the rate of anywhere else. Temperatures in the Arctic are climbing dangerously high. The summer of 2014 has seen incredible temperatures across the Arctic – averaging a frightening 10 Deg C above average. Warm Atlantic currents are inundating the Arctic Ocean warming both the subsea permafrost and the Arctic Ice sheets dramatically. If temperatures are breached and permafrost begins to thaw uncontrollably, microbial action on land may result in catastrophic pulses of methane gas, 26 times more potent than CO2 in the short term. If the sub-sea permafrost dome is eroded in the East Siberian Arctic Shelf, it may offer  many gigatons of methane hydrates a direct path to the atmosphere. We are living in dangerous times and the Cryosphere’s response may make dystopian movies seem mild. More and more scientists are warning that we should possibly prepare for a human extinction event.

Introduction

The cryosphere is the technical term for the ecosystem of the frozen, polar ice caps and include the Arctic and Antarctic. Both areas play a crucial role in maintaining a stable planetary climate and ecological system. Instabilities here have enormous implications for the entire planet. Unfortunately these regions are also the fastest warming ones on the planet. Warming atmosphere, warming oceans and pollution are bringing dramatic change to these regions that have remained unchanged for thousands of years.  The graph below shows that the increase in global warming in the Arctic region is double that of any other region on the globe. NASA estimates that permafrost is warming even faster than air temperatures – at a rate between 1.5 to 2.5 degrees Celsius. The Greenland glacier in the Arctic and six glaciers in Amundsen Bay of West Antarctica are calving at high rate.

 

Figure 1: Averaged temperature change from 2006 to 2012 referenced to historical mean temperature from 1951 to 1980 as a function of latitude

(Source UNEP 2012, Keeping Track of our Changing Environment, original source of data – NASA)

 

 Estimates of Permafrost Carbon Pool Estimates for the 0– 100 cm depth:

  • 1220 Gt – Sombroek et al. (1993),
  • 1395 Gt – Post et al. (1982),
  • 1462 to 1548 Gt – Batjes (1996),
  • 1502 Gt  -Jobba´gyand Jackson (2000),
  • 1576 Gt – Eswaran et al. (1993)

Estimates for the 0 – 200 cm depth:

  • 2376 – 2456 Gt [Batjes, 1996]

Estimate for the 100 – 200 cm depth:

  • 491 Gt [Jobba´gy and Jackson, 2000]

Estimate for the 200 – 300 cm depth:

  • 351 Gt[Jobba´gy and Jackson, 2000]
The implication of this dramatic change in temperature in the Arctic are quite serious for all of humanity. In the cryosphere, During the summer, parts of the Arctic warm briefly, stimulating plant and animal growth. However, this growth is only supported on a very thin layer of topsoil. Beneath that, the ground remains permanently frozen. When the cold season occurs once again, the Arctic’s extremely cold conditions prevent dead plants and animals from decomposing. As a result,  another layer of undecomposed flora and fauna is added to the reservoirs of organic carbon already accumulated just beneath the topsoil.

Over thousands of years, this has resulted in anywhere from 1400 GtCO2 eq to 1850 GtCO2 eq stored in the permafrost. Currently the Arctic is a net carbon sink but with global warming reaching a tipping point, it can switch to becoming a net carbon source. When the permafrost reaches the thawing tipping point, huge stores of carbon will become available to microbes to digest, releasing vast amounts of CO2 and methane. Once this tipping point is reached, such a large amount of GHG may be liberated that it may begin the cycle of unstoppable global warming – there is likely no treatment. Our only chance is prevention. There are two sources of carbon in the cryosphere:

  1. permafrost
  2. methane hydrates (also called methyl clathrates)

Permafrost

Permafrost is technically defined as soil with temperatures at or below 0 degrees Celsius for at least two or more  years in a row.

Carbon was buried in permafrost by processes that took thousands of years. During the last ice age, great ice sheets covered most of the continents. As they spread out and then shrunk back, the heavy fields of ice ground up the rock underneath them into a very fine dust called loess or glacial flour. The ice sheets produced a huge amount of this powdered rock, and wind and rain deposited it onto the soil. As the ice sheets added loess to the soil, the soil got thicker. As the soil built up, the active layer on top stayed the same thickness. The active layer freezes and thaws each year, and plants can grow in it. But underneath the active layer, roots and other organic matter were frozen into the permafrost, where they can’t decay. Most of the organic matter consists of partially decayed roots, whole roots, and other plant material. However, there are also animals and animal material frozen in the ground  – NSIDC
In warmer areas, permafrost can absorb enough heat  in the summer time to let the topmost layer of soil, called the active layer, to temporarily thaw, allowing plants to grow and animals to find food. Underneath this layer, the soil remains frozen, preventing decay and preserving plant matter and organic material for thousands of years. If temperatures rise and permafrost thaws, the organic material decays, and the soil becomes wet and marshy. As the organic material rots, most of the carbon is released into the atmosphere as carbon dioxide, but in this moist environment, a significant fraction of the carbon is released as methane, a potent greenhouse gas.  When the frozen ground thaws, the soil may also collapse and creates holes in the tundra, exposing the old carbon directly to the atmosphere and accelerating its decay. As of 2012, major climate models still do not include CO2 and methane emissions from permafrost, even though the 13 million square kilometers of permafrost contain half the known stores of soil carbon on the planet.  As long as the permafrost remains frozen, bacteria and fungi have no access to decompose it. However, when permafrost thaws, the story changes. Now, these organisms can respire the defrosted carbon to methane or carbon dioxide and release it into the atmosphere.  Conversion of this currently frozen carbon pool to GHGs has the potential to double the amount of CO2 in the atmosphere on a timescale that is similar to human inputs.  This could cause runaway global warming.

Methane Hydrates (also called Methane Clathrates)

Methane hydrate is an ice-like substance formed when CH4 and water combine at low temperature (up to ~25ºC) and moderate pressure (greater than 3-5 MPa, which corresponds to combined water and sediment depths of 300 to 500 m). Globally, an estimated 99% of gas hydrates occurs in the sediments of marine continental margins at saturations as high as 20% to 80% in some lithologies; McIver (1981), Collett et al. (2009) estimate the remaining 1% is mostly associated with sediments in and beneath areas of high-latitude, continuous permafrost. Nominally, methane hydrate concentrates CH4by ~164 times on a volumetric basis compared to gas at standard pressure and temperature. Warming a small volume of gas hydrate could thus liberate large volumes of gas. A challenge for assessing the impact of contemporary climate change on methane hydrates is continued uncertainty about the size of the global gas hydrate inventory and the portion of the inventory that is susceptible to climate warming. This paper addresses the latter issue, while the former remains under active debate. Dickens (2011) recently estimated 7×102 to 1.27×104 Gt carbon (Gt C) to be sequestered in marine gas hydrates alone, while Shakhova et al. (2010a) estimate 3.75×102 Gt C in methane hydrates just on the East Siberian Arctic shelf (ESAS). A conservative estimate (Boswell & Collett 2011) for the global gas hydrate inventory is ~1.8×103 Gt C, corresponding to CH4 volume of ~3.0×1015 m3 if CH4 density is taken as 0.717 kg/m3. In the unlikely event that 0.1% (1.8 Gt C) of this CH4 were instantaneously released to the atmosphere, CH4 concentrations would increase to ~2900 ppb from the 2005 value of ~1774 ppb (IPCC 2007). (Source: Ruppell, 2011)

 

Figure 2: Schematic cross-section from a high-latitude ocean margin (onshore permafrost and shallow offshore subsea permafrost) in Sectors 1 and 2 on the left, across a generic upper continental slope (Sector 3), and into a deepwater marine gas hydrate system (Sector 4) and an area of gas seeps on the right (Sector 5). The horizontal scale on Arctic Ocean margins may range from less than 102 to 103 km. GHSZ sediments usually have low saturations of methane hydrate, except in permeable sand layers shown here with coarser-grained texture. Ice-bonding within permafrost follows similar relationships. New microbial CH4(green) can be formed where labile organic carbon is available, including within the GHSZ, beneath lakes in permafrost areas, and in newly thawed sediments above subsea or terrestrial permafrost. Red zones at and below the seafloor denote anaerobic CH4 oxidation (coinciding with sulfate reduction), which occurs in zones that thin with increasing CH4 flux. The orange zone onshore denotes seasonal aerobic CH4 oxidation in the annually thawed active layer. CH4 oxidation associated with lakes in permafrost is not depicted. Methane, not necessarily derived from gas hydrates, is emitted directly to theatmosphere at ebullition sites in shallow lakes within permafrost and probably in open water on shallow Arctic shelves. Methane emitted at the seafloor at greater water depths is not likely to reach the atmosphere. (Ruppel, 2011)

How Much Potential Emissions in the Arctic?

The Arctic is a sleeping giant that will be roused awake by global warming. It holds half the store of global terrestrial carbon and current estimates are that there are between 750 and 850 GtCO2 in the atmosphere in the form of CO2  while there is approximately 1400 to 1850 GtCO2 locked in the Arctic (NASANSIDC), most located in thaw-vulnerable topsoils within 3 meters of the surface. This is just a conservative estimate however and can be considerably larger –  other scientists such as Dr. Natalia Shakhova, an Arctic ice researcher estimates 1400 GtCO2 eq for carbon locked in permafrost in one region she is studying alone (The East Siberia Arctic Shelf – ESAS) alone. Whatever the actual number, these amount dwarfs the current dangerous anthropogenic levels by two orders of magnitudes and as other researchers such as Dr. Rose Cory warn, that amount is likely to be released in a very short time period (tens to hundreds of years). How much emissions will come from the Arctic as we reach tipping points and how quickly will it be released? This is the big and complex question. As the Arctic warms, it grow vegetation such as trees which become carbon sinks. It is not at all clear what all the sources and sinks are so the net amount is not currently predictable. Climate modelers desperately need good cryosphere data to feed into their models; underlying the critical nature of the research. NASA’s five year Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) project is one large scale effort to try to gather this data. The team uses an old C-23 prop plane and performs regular low level (152 meter above ground) flights across the Arctic. The sensitive onboard instruments sample for various GHG gases. Air samples are shipped to the University of Colorado’s Institute for Arctic and Alpine Research Stable Isotope Laboratory and Radiocarbon Laboratory in Boulder for analyses to determine the carbon’s sources and whether it came from thawing permafrost. The early results are troubling. Principal research scientist Charlie Miller said “We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze. To cite another example, in July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels. That’s similar to what you might find in a large city.”

Arctic Tipping Points

Although the Arctic  is far away both geographically and from most people’s mind, it is home to the greatest concentration of tipping points on the  planet. The paper Tipping Elements in the Arctic Marine Ecosystem published in AMBIO  by Carlos M. Duarte et al.(2012) provide a survey of the many tipping points in the Arctic:

Table 1: List of  tipping points in the Arctic (Source: Tipping Elements in the Arctic Marine Ecosystem, Duarte et al., AMBIO 2012)

Figure 3: Diagram showing Arctic Ocean tipping point. Regime A (above dotted horizontal line) is the Arctic’s current stable regime and is dominated by diatom plankton which absorb CO2. Increased global warming is leading to accelerated melting Arctic ice cover. Diminished enough, it can lead to an abrupt state change (vertical black line) to Regime B (below the dotted horizontal line) in which diatomic plankton produce vanishes and is replaced by picoplankton production which generates instead of consumes CO2 (Source:  Tipping Elements in the Arctic Marine Ecosystem AMBIO 2012, Duarte et al. )

Sea Ice

The characteristic element of the Arctic ecosystem is ice and the presence and importance of ice already determine the existence of a critical tipping point for the Arctic marine ecosystem. This dominant tipping point is given by the temperature at which a water phase change occurs going from solid to liquid phase. This happens at:

  • Zero deg C for freshwater
  • approximately -1.8C for seawater (the salt content lowers the freezing point)

Hence, ice is a tipping element that responds abruptly to changes in temperature across this tipping point. Warming and loss of ice cover drive  many other changes that amplify climate warming regionally and have the potential to affect climate globally [Lenton et al. 2012]. These changes include:

  1. the reduction in albedo with declining sea-ice extent which drives a positive feedback conducive to heating of the Arctic Ocean [Perovich et al. 2007]
  2. changes in the submarine irradiance field and the heat budget of the Arctic Ocean
  3. increased air-sea fluxes of green-house gases and other climate-active substances across the open water surface [Chang and Dickey 2004]; [Perovich et al. 2007]; [Ru´iz-Halpern et al.2010]

Moving beyond this tipping point will set in motion most of the other tipping elements contained in the Arctic region as indicated in the Table above.

Permafrost

Permafrost is the frozen ground found in the Arctic. It’s thawing leads to many serious consequences:

  1. Thawing of the permafrost leads to thermokarst formation by which solid soils turns into fluid soil and eventually ponds and aquatic ecosystems [Lawrence et al. 2008].
  2. Thermokarst lakes and ponds are formed in a depression by meltwater from thawing permafrost, often enhanced by the collapse of ground levels associated with permafrost thawing [Jorgenson et al. 2006]; [Lawrence et al. 2008]; [Prairie et al. 2009].
  3. Thermokarst lakes and ponds have become increasingly common in the Arctic, including Siberia and the Canadian Arctic
  4. They can extend to 10–30% of arctic lowland landscapes with further climate change [Jorgenson et al. 2006]
  5. Permafrost thawing, together with increased precipitation, increases freshwater discharge to the Arctic ecosystem which has increased by about 30% in recent years [Peterson et al. 2002]
  6. Thawing enhances the movement of organic materials and sediments hitherto trapped in frozen soils to the Arctic Ocean[Guo et al. 2007]
  7. Frozen soils and sediments contain large amounts of methane hydrates that can be released to the atmosphere [Kvenvolden 1988]; [van Huissteden et al. 2011]

Methane Hydrates

At intermediate depth, ocean temperatures are also increasing globally in every part of the ocean due to global warming and subsequently releasing methane previously trapped in methane hydrate deposits.

  1. Recent assessments have found substantial outgassing of methane liberating from hitherto frozen methane hydrates on the Siberian shelf [Shakhova et al. 2010] as well as in thawing Arctic permaforst.
  2. Models suggest that a global 3C warming could release between 35 and 94 Gt C of methane, which could add up an additional 0.5C to global warming [Maslin et al. 2010]
  3. The most likely scenario is that of gradual, long-term chronic methane release rather than an abrupt release event, so that a tipping point on the global climate due to abrupt methane release from the Arctic appears, at this point, unlikely [Lenton, AMBIO 2012]

Ocean Biogeochemistry

  1. As ice cover declines, ocean water becomes exposed and solar radiation penetrates and is absorbed in the water, while the previous ice cover reflected radiation back to the atmosphere. This alters the heat budget of the Arctic Ocean, leading to warming of the waters and acceleration of the melting of ice [Perovich et al. 2007].
  2. As more light reaches the seawater when ice is lost, primary plankton production is expected to increase [Arrigo et al. 2008]; [Wassmann et al. 2008], with the associated release of dissolved organic compounds, which add to the increased delivery of organic matter from rivers.
  3. Colored organic matter dissolved in seawater absorbs light strongly and dissipates the energy as heat (Chang and Dickey 2004), thereby further increasing the warming of Arctic water once the ice cover is lost.
  4. Warming of Arctic water reduces the solubility of gases, including CO2, and may lead to increased partial pressure of CO2 and its release to the atmosphere [Siegenthaler and Sarmiento 1993].
  5. Increased ice melting at sea and on land leads to a higher export of freshwater from the Arctic, which adds buoyancy and stabilizes the water column of the Arctic water exported south along the Greenland coast [Dickson et al. 2002]. This added stability may affect deep-water formation in the North Atlantic and eventually slow down the thermohaline circulation [Dickson et al. 2002], which may trigger abrupt regional climate change [Driscoll and Haug 1998]
  6. Whereas such abrupt climate changes from the collapse of the thermohaline circulation may be a distant tipping point, a slowing down is robustly predicted [Lenton 2012]

Greenland Ice Sheet

  1. The thick ice sheet in Greenland is also destabilized – evidence from increased ice melting and iceberg release from the Greeland ice sheet [Zwally et al. 2002]; [Velicogna and Whar 2006]
  2. Thinning of the Greenland ice sheet and increased glacial discharge will further increase the export of freshwater from the Arctic Ocean , adding to the processes indicated above
  3. The Greenland ice sheet contains a enormous volume of ice and its loss can lead to a 6–7 m increase in sea level rise [Gregory et al. 2004]
  4. Whereas the time scales involved in such loss extend over centuries [Lenton et al. 2008], the process of melting of the ice sheet is self-accelerating. Destabilization of the Greenland ice sheet, which may have already been initiated [Gregory et al. 2004]; [Lenton et al. 2008]; [Lenton 2012], is,thus, another tipping point of global consequences as it will exacerbate problems of coastal erosion and flooding of low-laying areas already impacted by climate change.

Terrestrial Ecosystems

  1. In the subarctic, warmer temperatures are leading to dieback of the boreal forest [Chapin et al. 2004]; [Soja et al. 2007] and desiccation of extensive peat deposits [Davidson and Janssens 2006]
  2. Peat desiccation is of particular concern because it may subsequently lead to subsurface fires, such as those experienced in Russia in the summer of 2010 [Yurganov et al. 2011], and the release of massive amounts of CO2
  3. Peat deposits may release an estimated 100 Gt C by 2100 through forest fires or aerobic decomposition of dried peat deposits [Davidson and Janssens 2006]; [Dorrepaal et al. 2009]

Human Activity

  • Reduced ice cover in the Arctic Ocean is already leading to increased human activity in the Arctic, including shipping, oil, gas and mineral exploitation, and fisheries (Wassmann 2008, 2011), which may itself affect the trajectories and impacts of climate change in the Arctic [Huntington et al. 2007].
  • The Arctic region contains many of the key tipping elements of the Earth System which—if set in motion—can generate profound global changes (cf. Lenton  AMBIO 2012).

 Extreme Weather in North America linked to Arctic Sea Ice

Cornell University researchers Charles H. Greene, professor of earth and atmospheric sciences, and Bruce C. Monger, senior research associate  are disentangling the mechanics of how the Arctic climate system has a major influence on extreme weather events in North America such as the recent record breaking heat wave and hurricanes such as Hurricane Sandy. In their paper An Arctic Wild Card in the Weather published in the June 2012 issue of the journal Oceanography, they show how Arctic sea ice changes are triggering a domino effect leading to increased odds of severe weather outbreaks in the Northern Hemisphere’s middle latitudes. For a condensed, simplified explanation, go here. Once any of these tipping points is reached, it may set off an unstoppable positive feedback effect which can lead to accelerating the chances of other tipping points occurring. With such enormous amounts of methane sealed underneath the cryosphere, even a small percent leaked directly to the atmosphere due to global warming could increase the methane burden many times, leading modern civilization and the planet into completely uncharted territory. The Arctic is therefore not at the periphery, but the core of the Earth System and we should all be concerned as Arctic tipping points

Figure 4: Arctic Sea Ice Freeze and Thaw Millions of Square Km recorded from 1979 to  2012. Click on the image to go to the Interactive Display or click here

 

NCAR scientists Marika Holland  shows dramatic Sea Ice Loss

Arctic Amplification

Arctic amplification describes the tendency for high Northern latitudes to experience enhanced warming or cooling relative to the rest of the Northern Hemisphere due to the presence of snow and sea ice, and the feedback loops that they trigger. To understand the important role that sea ice plays in moderating global temperatures, readers need to have an understanding of the reflective abilities of snow, ice and open ocean.

Albedo

Figure 5: Albedo (Source: NSIDC)
Albedo (α)  is a non-dimensional, unitless quantity that indicates how well a surface reflects solar energy. Albedo is commonly thought of as the “whiteness” of a surface and varies between 0 and 1, with 0 meaning black and 1 meaning white. As an example, blacktop has a much lower albedo than concrete because the black surface absorbs more energy and reflects very little energy. A value of 0 means the surface is a “perfect absorber” that absorbs all incoming energy. Absorbed solar energy can be used to heat the surface or, when sea ice is present, melt the surface. A value of 1 means the surface is a “perfect reflector” that reflects all incoming energy. Albedo generally applies to visible light, although it may involve some of the infrared region of the electromagnetic spectrum. Here are the facts about albedo in the Arctic:

  • Sea ice has a much higher albedo compared to other earth surfaces, such as the surrounding ocean
  • A typical ocean albedo is approximately 0.06
  • bare sea ice varies from approximately 0.5 to 0.7.
  • Hence the ocean reflects only 6 percent of the incoming solar radiation and absorbs the other 94%, while sea ice reflects 50 to 70 percent of the incoming energy. The sea ice absorbs less solar energy and keeps the surface cooler.
  • Snow has an even higher albedo than sea ice, and so thick sea ice covered with snow reflects as much as 90 percent of the incoming solar radiation. This serves to insulate the sea ice, maintaining cold temperatures and delaying ice melt in the summer.
  • After sea ice snow begins to melt, shallow melt ponds form having an albedo of approximately 0.2 to 0.4
  • The overall surface albedo of sea ice with melt ponds therefore drops to about 0.75
  • As melt ponds grow and deepen, the surface albedo can drop to 0.15. As a result, melt ponds are associated with higher energy absorption and a more rapid ice melt
  • Water that is above zero degrees will also contribute to melting of sea ice

Sea Ice Thermodynamics

Figure 6: Seasonal cycle of arctic sea ice growth and melt over one year. Left y-axis represents thickness of sea ice and snow, referenced to the top of the ice. Modified from Maykut and Untersteiner (1971). (Source: NDIDC)

Sea Ice Growth and Melt Cycle

  1. Sea ice growth begins during the autumn when incoming solar energy decreases and air temperatures fall below the freezing point
  2. Ice growth continues through the winter. Ice becomes thicker as heat continually transfers from the relatively warm ocean to the cold atmosphere
  3. As the sun climbs higher in the sky and solar energy increases in the spring and summer, the temperatures rise and the ice begins to melt
  4. If the ice has not grown thick enough during the autumn and winter, it will completely melt during the spring and summer
  5. However, if the ice grows thick enough during the growth season, it will remain through the summer, become thinner through the melt season, and thicken again the following autumn
  6. Such ice may remain for several years, thinning during the summer and regrowing the following autumn and winter.
  7. Where growth outpaces melt, ice gradually becomes thicker over the years. Sea ice eventually reaches  thermodynamic equilibrium state
  8. Ice grows due to a transfer of heat from the relatively warm ocean to the cold air above
  9. Ice insulates the ocean from the atmosphere and inhibits this heat transfer
  10. The amount of insulation depends on the thickness of the ice; thicker ice allows less heat transfer
  11. If the ice becomes thick enough that no heat from the ocean can be conducted through the ice, then ice stops growing
  12. This is called the thermodynamic equilibrium thickness. It may take several years of growth and melt for ice to reach the equilibrium thickness
  13. In the Arctic, the thermodynamic equilibrium thickness of sea ice is approximately 3 meters (9 feet). However, dynamics can yield sea ice thicknesses of 10 meters (30 feet) or more
  14. Equilibrium thickness of sea ice is much lower in Antarctica, typically ranging from 1 to 2 m (3 to 6 feet)
With global warming, the sea ice retreats and sunshine that would have normally been reflected back to space by the higher albedo brighter ice is instead absorbed by the lower albedo ocean, which heats up, melting even more ice. As the world has warmed since the fossil-fuel revolution after World War II, Arctic temperatures have increased at more than twice the global rate. A dramatic indicator of this warming is the loss of Arctic sea ice in summer, which has declined by 40 percent in just the past three decades, an area of lost ice equivalent to approximately 1.3 million square miles. Extra heat entering the vast expanses of open water that were once covered in ice is released back to the atmosphere in the fall when the atmosphere acts as a heat sink. This has led to an increase in near-surface, autumn air temperatures of 2 to 5 degrees C (3.6 to 9 degrees F) over much of the Arctic Ocean during the past decade. This extra atmospheric heat cannot help but affect the weather, both locally and on a large scale. Mounting scientific evidence is providing support that extreme weather phenomena in recent years — such as prolonged cold spells in Europe, heavy snows in the northeastern U.S. and Alaska, heat waves in Russia and North America, Hurrican Sandy — may be related to Arctic amplification. The Arctic ecosystem is intimately connected with the rest of the planet in many ways and if it undergoes major change, such as melting permafrost or sea ice, it will impact the entire planet in a profound way.

Basic Mechanics of the Cryosphere

In the simplest terms, the cryosphere is the frozen water part of the Earth system. It has two major components: continental or land ice and sea ice. In continental ice, soil that has been frozen for more than 2 years  is referred to as Permafrost. It can exist on land or as subsea permafrost beneath the ocean such as in the shallow Arctic Sea.  While it is frozen, the cryosphere acts as a lid to contain vast deposits of methane gas. If this permafrost thaws, however, vast amounts of gas can be liberated.

Figure 7a: Permafrost Infographic (Source: Thinkprogress)

Figure 7b: The Arctic Ecosystem (source: International Arctic Research Center)

The Arctic is the fastest warming region on the planet. As it warms frozen water, in the form of permafrost and glaciers and frozen ice begin to thaw.

Permafrost Degradation

Permafrost is defined as land that has remained frozen for more than 2 years. As permafrost degrades and turns from ice to water due to the warming climate, the organic matter, trapped in the frozen ground for thousands of years, is freed and bacterial decay rapidly sets in, releasing methane to the atmosphere.

Clathrate and Methane Hydrates

At greater depths in the sedimentary column, methane may exist in a second form, trapped in clathrate molecules. A clathrate is a naturally-occurring chemical substance which chemically consists of one type of molecule forming a cage-like crystalline lattice  (called the host) which traps a second type of molecule (called the guest). In this case, the host is water and the guest is methane, hence the term ‘methane hydrate’.  It is a white, crystalline solid that looks just like ice with the one difference that it is only stable at low temperatures and/or high pressures. When the low temperature / high pressure condition is removed, the hydrate molecule decomposes, liberating the guest methane molecule.

Figure 8: Global Estimate of Methane Hydrates (Source: Der Spiegel)

The Methane Gun Hypothesis 

  1. methane clathrate at shallow depth begins melting
  2. because of the shallow depth, the methane does not oxidize in the water column but instead goes directly into the atmosphere, accelerating atmospheric and oceanic warming
  3. this atmospheric warming feeds back onto the methane hydrates, causeing more melting of even larger and deeper clathrate deposits
  4. This results is a relatively sudden massive outgassing of methane, the so-called firing of the Methane Gun.

Miscellanous Facts

  • It has been known for many years that methane is being emitted from Siberian swamplands previously covered by permafrost, trapping an estimated 1,000 billion tons of methane.
  • Permafrost on land is now seasonally melting and with each season melting penetrates to greater depth, ensuring a methane venting rises further with each passing year
  • Methane clathrate has accumulated over the East Siberian continental shelf where it is covered by sediment and seawater up to 50 meters deep.
  • An estimated 1,400 billion tons of methane is stored in these deposits; total human greenhouse gas emissions (including CO2) since 1750 amount to some 350 billion tons.

Significant methane release can occur when:

  1. on-shore permafrost is thawed by a warmer atmosphere (predicted to occur on century timescale)
  2. undersea clathrate at relatively shallow depths is melted by warming water

Follow the Unfolding Story: Signs that the Arctic Methane Tipping Point may be Beginning

The following studies, in chronological order paint a dramatic picture of a dangerous Tipping Point starting to emerge.

NOAA 2009 Study: Observational constraints on recent increases in the atmospheric CH4burden

Measurements of atmospheric CH4 from air samples collected weekly at 46 remote surface sites show that, after a decade of near-zero growth, globally averaged atmospheric methane increased during 2007 and 2008. During 2007, CH4 increased by 8.3 ± 0.6 ppb. CH4 mole fractions averaged over polar northern latitudes and the Southern Hemisphere increased more than other zonally averaged regions. In 2008, globally averaged CH4 increased by 4.4 ± 0.6 ppb; the largest increase was in the tropics, while polar northern latitudes did not increase. Satellite and in situ CO observations suggest only a minor contribution to increased CH4 from biomass burning. 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. NOAA’s most recent graph show that Methane is on the rise again.

Figure 9: NOAA Annual Greenhouse Gas Index

March 2010 Study: Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Arctic Shelf  

The 2009 NOAA study’s optimistic results of a decade of no-growth in CH4 was short lived when Dr. Igor Semiletov and  Dr. Natalia Shakhova’s results were published. Their study, published in March 2010 in Science summarizes observations from a 2003 to 2008 Expedition to the East Siberian Arctic Shelf (ESAS) by [Dr. Igor Semiletov Dr. Natalia Shakhova et al. 2010]

Figure 10: Bathymetric map of the Arctic ESAS is area in red. (Source: Thinkprogress)
Until Dr. Semiletov’s expedition in 2003,  it was simply assumed that ESAS subsea permafrost was unlikely to be a source area for methane because it was all frozen solid. Dr. Semiletov’s research produced the surprising result that the surface and especially bottom waters were super-saturated with methane, implying that outgassing from the sea-bed was occurring. Further fieldwork went on to discover plumes of methane gas bubbling up to the surface. In deeper waters, methane does not make it all the way up to the atmosphere – it all dissolves in seawater  and microbes have a chance to convert it to CO2 – but over the shallower waters of the ESAS this is not the case. There, the methane has a direct path to the atmosphere. Air sampling surveys over the ESAS revealed great variability in methane levels: against the global background level of 1.85ppm:

  • they were elevated by typically 5-10% up to 1800m in height
  • local spikes over gas-productive areas as high as 8ppm

The team’s observations showed that the permafrost submerged on the shelf is perforated and leaking large amounts of methane into the atmosphere:

  • more than 80 percent of the deep water had methane levels around eight times higher than found in normal seawater
  • more than half of surface water had methane levels around eight times higher than found in normal seawater


Dr. Shakhova explaining the Research Study ResultsSemiletov and team calculated the annual CURRENT total methane flux from the ESAS to the atmosphere to be 7.98Tg C-CH4, or approximately 10.64 million tonnes of methane per year, a figure similar to what, up until now, was thought to be the methane emissions of the entire world’s oceans. To put this figure in perspective, domestic animals emit about 80 million tonnes a year. The team is not worried so much about the current methane flux, as it is about the potential methane flux should global warming continue. According to another Arctic methane researcher, professor Euan Nisbet, Royal Holloway, University of London, “The Arctic is the fastest warming region on the planet, and has many methane sources that will increase as the temperature rises.” Semiletov et al warn that the release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming. “Ocean-bottom permafrost contains vast amounts of carbon, and experts are concerned that its release as methane gas would lead to warmer atmospheric temperatures, thus creating a positive-feedback loop that would lead to more methane escaping from the permafrost and more global warming,” they said. When the team estimated the methane present as free gas and methane hydrate beneath or within the ~1.5 million sq km of the submarine permafrost of the ESAS, they calculated a total  >1000 Gt. Finally, Semiletov and team guessed where this 1000 Gt may liberate and thought the most likely area would be regions of permafrost affected by active fault zones and by open taliks – zones of permafrost that have melted. This was estimated to be 1-2% and 5-10% of the total area respectively. Semiletov arrived at a figure of  50Gt of methane hydrate at risk of destabilisation leading to “abrupt release at any time” (ref. 2). To see why scientists are deeply worried by this, compare this against annual anthropogenic methane emissions which in 2010 were approximately 275 million tonnes (or 0.275 Gt). Since methane has a global warming potential 25x greater than CO2 (as stated in the IPCC AR4),  an abrupt 50 Gt methane release would be like releasing 40 years’ worth of anthropogenic carbon dioxide emissions (at 2009 emission levels) all at once. Dr. Shakhova said that scientists are concerned because the undersea permafrost “has been showing signs of destabilization already,” and “If it further destabilizes, the methane emissions… would be significantly larger.”

Aug 2010: Dr. Shakhova et al. Release Paper: Geochemical and geophysical evidence of methane release over the East Siberian Arctic Shelf

Abstract The East Siberian Arctic Shelf (ESAS), which includes the Laptev Sea, the East Siberian Sea, and the Russian part of the Chukchi Sea, has not been considered to be a methane (CH4) source to hydrosphere or atmosphere because subsea permafrost, which underlies most of the ESAS, was believed, first, not to be conducive to methanogenesis and, second, to act as an impermeable lid, preventing CH4escape through the seabed. Here recent observational data obtained during summer (2005–2006) and winter (2007) expeditions indicate the ubiquitous presence of elevated dissolved CH4 and an elevated atmospheric CH4 mixing ratio. The CH4 data were also analyzed together with high resolution seismic (HRS) data obtained by means of a “Sonic M-141” system consisting of a high-resolution profiler and side-scan sonar mounted in a towed fish during the Transdrift-X Expedition (2004) onboard the R/V Yakov Smirnitskiy. Results show anomalously high concentrations of dissolved CH4 (up to 5 μM) and an episodically (nongradually) increasing atmospheric mixing ratio of CH4 (up to 8.2 ppm) in some areas of the ESAS. A most likely source is year-round CH4 release through taliks (columns of thawed sediments within permafrost) from seabed CH4 reservoirs such as shallow hydrates and geological sources. Such releases occur not only within the areas underlain by fault zones but also outside of them. This points to permafrost’s failure to further preserve CH4 deposits in the ESAS. The total amount of carbon preserved within the ESAS as organic matter and ready to release CH4 from seabed deposits is predicted to be ∼1400 Gt. Release of only a small fraction of this reservoir, which was sealed with impermeable permafrost for thousands of years, would significantly alter the annual CH4 budget and have global implications, because the shallowness of the ESAS allows the majority of CH4 to pass through the water column and escape to the atmosphere.

Sept 2010 Study: Gas escape features off New Zealand: Evidence of massive release of methane from hydrates from interglacial periods

Figure 11: Davy’s figure from the Journal Article
Bryan Davy, Ingo Pecher, Ray Wood, Lionel Carter and Karsten Gohl published this paper in Geological Research Letters, 2010. It was based on a study they conducted on the seafloor off the coast of New Zealand in an area known as the Chatham Rise.  Multibeam swath bathymetry data from the southwest margin of the Chatham Rise showed gas release features over a region of at least 20,000 km. Gas escape features, interpreted to be caused by gas hydrate dissociation, include:

  1. 10 features, 8–11 km in diameter at 800-1,100 m water depth
  2. 1,000 features, 1–5 km in diameter at 800–1,100 m water depth
  3. 10,000 features (estimated), ∼150 m in diameter at 500–700 m water depth

According to the team: In the latter depth range sub‐bottom profiles show similar gas escape features (pockmarks) at disconformities interpreted to mark past sea‐level low stands. The amount of methane potentially released from hydrates at each of the largest features is ∼7*10exp12 g. If the methane from a single event at one 8–11 km scale pockmark reached the atmosphere, it would be equivalent to ∼3% of the current annual global methane released from natural sources into the atmosphere.

Feb 2011 Study: Amount and Timing of Permafrost Carbon Release in Response to Climate Warming

Abstract: 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. We use surface weather from three global climate models based on the moderate warming, A1B Intergovernmental Panel on Climate Change emissions scenario and the SiBCASA land surface model to estimate the strength and timing of the PCF and associated uncertainty. By 2200, we predict a 29–59% decrease in permafrost area and a 53–97 cm increase in active layer thickness. By 2200, the PCF strength in terms of cumulative permafrost carbon flux to the atmosphere is 190 ± 64 Gt C. This estimate may be low because it does not account for amplified surface warming due to the PCF itself and excludes some discontinuous permafrost regions where SiBCASA did not simulate permafrost. 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. Conclusion: 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.

Figure 12: Permafrost Carbon Flux from Amount and timing of permafrost carbon release in response to climate warming

This is the conclusion of lead scientist Kevin Shaefer of the National Snow and Ice Data Center (NSIDC) and others in the study. They now expect the permafrost to become a major source of atmospheric carbon in the next few decades and that thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100. In fact, the researchers predict: “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.” University of Alaska scientist Vladimir Romanovsky said that in northern Alaska, 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. Nature reported that the latest estimate is that some 18.8 million square kilometres of northern soils hold about 1,700 billion tonnes of organic carbon —  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.

June 2011 Expedition to ESAS: Amazing Observations by Dr. Igor Semiletov of Many Giant Methane Plumes, some 1 Km Wide

Figure 13: Area of East Siberian Arctic Shelf where Giant Plumes Discovered (Source: The Independent)
In their most recent late 2011 expedition to the East Siberian Arctic Shelf north of Siberia, Dr. Igor Semiletov and Dr. Natalia Shakhova made another astonishing and scary discovery.   In a joint expedition between the International Arctic Research Centre at the University of Alaska Fairbanks and the University of Georgia, Athens, the team witnessed methane plumes, the size and scale of which were unprecedented. “In a very small area, less than 10,000 square miles, we have counted more than 100 fountains, or torch-like structures, bubbling through the water column and injected directly into the atmosphere from the seabed,” Dr Semiletov said.
  A 2011 paper (ref. 1) reported a dramatic warming of the bottom water layer over the ESAS coastal zone (<10 m depth), since the mid-1980s, of 2.1°C. The warming was attributed to:

  • atmospheric changes involving enhanced summer cyclonicity
  • reduction in ice extent
  • the consequent lengthening of the summer open-water season and – consequential to that –
  • solar heating of the water column

The team had witnessed the extraordinary results of that warming. In late summer 2011, the Russian research vessel Academician Lavrentiev conducted an extensive survey of about 10,000 square miles of sea off the East Siberian coast, deploying four highly sensitive instruments, both seismic and acoustic, to monitor the “fountains” or plumes of methane bubbles rising to the sea surface from beneath the seabed. “We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale – I think on a scale not seen before. Some of the plumes were a kilometre or more wide and the emissions went directly into the atmosphere – the concentration was a hundred times higher than normal,” he said. Dr Semiletov released his findings for the first time last week at the American Geophysical Union meeting in San Francisco. He is now preparing the study for publication in a scientific journal. The New York Time reported that in the same  paper it was said “…roughly 1 meter of the subsurface permafrost thawed in the past 25 years, adding to the 25 meters of already thawed soil. Forecasting the expected future permafrost thaw, the authors found that even under the most extreme climatic scenario tested this thawed soil growth will not exceed 10 meters by 2100 or 50 meters by the turn of the next millennium. The authors note that the bulk of the methane stores in the east Siberian shelf are trapped roughly 200 meters below the seafloor…”

 The NYT report went on to say that other scientists who have been studying  methane emissions in the atmosphere say they have not seen any significant surge in methane levels correlated to the Arctic sea-bed emissions. Ed Dlugokencky, one such researcher  says: “Based on what we see in the atmosphere, there is no evidence of substantial increases in methane emissions from the Arctic in the past 20 years.”
Dr.  Shakhova said that the Arctic is becoming a major source of atmospheric methane and the concentrations of the powerful greenhouse gas have risen dramatically since pre-industrial times, largely due to agriculture. “I am concerned about this process, I am really concerned. But no-one can tell the timescale of catastrophic releases. There is a probability of future massive releases might occur within the decadal scale, but to be more accurate about how high that probability is, we just don’t know,” Dr Shakova said. “The concentration of atmospheric methane increased unto three times in the past two centuries from 0.7 parts per million to 1.7ppm, and in the Arctic to 1.9ppm. That’s a huge increase, between two and three times, and this has never happened in the history of the planet,” she added. In a 2011, New York Times environmental article, Dot Com Leaders of Arctic Methane Project Clarify Climate Concerns

We would first note that we have never stated that the reason for the currently observed methane emissions were due to recent climate change. In fact, we explained in detail the mechanism of subsea permafrost destabilization as a result of inundation with seawater thousands of years ago. We have been working in this scientific field and this region for a decade. We understand its complexity more than anyone.  And like most scientists in our field, we have to deal with slowly improving understanding of ongoing processes that often incorporates different points of views expressed by different groups of researchers.

Yes, modeling is important. However, we know that modeling results cannot prove or disprove real observations because modeling always assumes significant simplification and should be validated with observational data, not vice versa. Much of our work includes this field validation. Last spring, we extracted a 53-meter long core sample from the East Siberian Arctic Shelf, to validate our conclusions about the current state of subsea permafrost. We found that the temperatures of the sediments were from 1.2 to 0.6 degrees below zero, Celsius, yet they were completely thawed. The model in the Dmitrenko paper [link] assumed a thaw point of zero degrees. Our observations show that the cornerstone assumption taken in their modeling was wrong. The rate at which the subsea permafrost is currently degrading largely depends on what state it was in when recent climate change appeared. It makes sense that modeling on an incorrect assumption about thaw point could create inaccurate results. [Dec. 29, 9:28 a.m. | Updated Dmitrenko disputes this reading of his paper. See comment below.]

Observations are at the core of our work now. It is no surprise to us that others monitoring global methane have not found a signal from the Siberian Arctic or increase in global emissions. [This refers to the work of Ed Dlugokencky and others; see his comments in my Dot Earth post.] The number of stations monitoring atmospheric methane concentrations worldwide is very few. In the Arctic there are only three such stations — Barrow, Alert, Zeppelin — and all are far away from the Siberian Arctic. We are doing our multi-year observations, including year-round monitoring, in proximity to the source. In addition to measuring the amount of methane emitted from the area, we are trying to find out whether there is anything specific about those emissions that could distinguish them from other sources. It is incorrect to say that anyone is able to trace that signal yet.

All models must be validated by observations. New data obtained in our 2011 cruise and other unpublished data give us a clue to reevaluate if the scale of methane releases from the East Siberian Arctic Shelf seabed is assessed correctly (papers are now in preparation). This is how science works: step by step, from hypothesis based on limited data and logic to expanded observations in order to gain more facts that could equally prove or disprove the hypothesis. We would urge people to consider this process, not jump to conclusions and be open to the idea that new observations may significantly change what we understand about our world.

On Dec. 29, 2011 9:28 a.m. Dr. Igor Dmitrenko, whose paper is cited above, disputes the interpretation of his work by Semiletov and Shakhova. He sent this comment, starting with a quote from their statement:

“The model in the Dmitrenko paper [link] assumed a thaw point of zero degrees. Our observations show that the cornerstone assumption taken in their modeling was wrong. The rate at which the subsea permafrost is currently degrading largely depends on what state it was in when recent climate change appeared. It makes sense that modeling on an incorrect assumption about thaw point could create inaccurate results.”

This assessment of the model we used is completely wrong! The model takes into account that water can remain unfrozen at temperature below 0 degrees – “…the simulated temperature of sediments down to 25 m is below 0°C (dark blue line in Figure 6). Note that the sediments can still remain unfrozen because of the salt contamination”, page 7, right column, first paragraph.

This comment by Dr. Semiletov clearly demonstrates that he even didn’t carefully read our paper. Figure 6 shows simulated temperature profiles below the seafloor as a function of depth with unfrozen sediments at temperature below 0°C in the upper 30 m layer.

July 2011 Chukchi Sea leg of ICESCAPE Mission: NASA Scientists Discover Massive Phytoplankton Blooms Growing Underneath Arctic Ice

If someone had asked me before the expedition whether we would see under-ice blooms, I would have told them it was impossible . This discovery was a complete surprise.

- Kevin Arrigo of Stanford University in Stanford, Calif., leader of the ICESCAPE mission

Part of NASA’s mission is pioneering scientific discovery, and this is like finding the Amazon rainforest in the middle of the Mojave Desert

- Paula Bontempi, NASA's ocean biology and biogeochemistry program manager

 

NASA discovers incredible phytoplankton blooms under Arctic

In yet another unpredictable twist, NASA scientists on the ICESCAPE mission have discovered massive phytoplankton blooms growing underneath Arctic Ice. ICESCAPE researchers observed blooms beneath the ice that extended from the sea-ice edge to 72 miles into the ice pack. Ocean current data proved that these blooms developed under the ice rather than drifting there from open water, where phytoplankton concentrations can be high. The phytoplankton were extremely active, doubling in number more than once a day. Blooms in open waters grow at a much slower rate, doubling in two to three days. These growth rates are among the highest ever measured for polar waters. Researchers estimate that phytoplankton production under the ice in parts of the Arctic could be up to 10 times higher than in the nearby open ocean. Fast-growing phytoplankton consume large amounts of carbon dioxide. The study concludes that scientists will have to reassess the amount of carbon dioxide entering the Arctic Ocean through biological activity if the under-ice blooms turn out to be common. “At this point we don’t know whether these rich phytoplankton blooms have been happening in the Arctic for a long time and we just haven’t observed them before,” Arrigo said. “These blooms could become more widespread in the future, however, if the Arctic sea ice cover continues to thin.” These extensive but shallow melt ponds act as windows to the ocean, letting large amounts of sunlight pass through the ice to reach the water below, said Donald Perovich, a geophysicist with the U.S. Army Cold Regions and Engineering Laboratory in Hanover, N.H., who studied the optical properties of the ice during the ICESCAPE expedition. The discovery of these previously unknown under-ice blooms also has implications for the broader Arctic ecosystem, including migratory species such as whales and birds. Phytoplankton are eaten by small ocean animals, which are eaten by larger fish and ocean animals. A change in the timeline of the blooms can cause disruptions for larger animals that feed either on phytoplankton or on the creatures that eat these microorganisms. “It could make it harder and harder for migratory species to time their life cycles to be in the Arctic when the bloom is at its peak,” Arrigo said. “If their food supply is coming earlier, they might be missing the boat.” (Source: NASA)

Dec 2011 New York Times Article: As Permafrost Thaws, Scientists Study the Risks

Justin Gillis, a writer for the New York Times, wrote an interesting article providing new information from scientists on the impacts of permaculture thawing. Gillis relates how scientists are reporting that wildfires are increasing across much of the north, and early research suggests that extensive burning could lead to a more rapid thaw of permafrost.

One fire, occuring in 2007  and named the Anaktuvuk River fire was started by a lightning strike set the tundra on fire.Historically the tundra plants consisting of lichens, mosses and delicate plants, was too damp to burn. But climate change in the area has dried these plants sufficiently to catch fire and burn.  The  fire burned about 400 square miles of tundra, something that lake sediment study revealed has not happened for 5,000 years. Scientists have also calculated that the fire and its aftermath sent a huge pulse of carbon into the air  and it thawed the upper layer of permafrost, triggering what may be permanent changes in the landscape. Michelle Mack is a scientist studying the Anaktuvuk fire and claims that “the fastest way you’re going to lose permafrost and release permafrost carbon to the atmosphere is increasing fire frequency.” The rapid change in the Arctic permafrost ecosystem leaves many open questions that researchers are under pressure to answer under very short time constraints.

While the Feb 2011 NOAA/NSIDC study showed that the Arctic and sub-Arctic regions could switch from being a carbon sink to becoming an carbon source  outputting  15 percent of today’s yearly emissions from human activities, these calculations were deliberately cautious. A recent survey queried 41 permafrost scientists for more informal projections. They estimated that:

  • if human fossil-fuel burning remained high
  • the planet warmed sharply

the permafrost gases could eventually equal 35 percent of today’s annual human emissions. Most scientists are not worried about the carbon in the permafrost breaking down quickly. Typical estimates range from one to more centuries.  The worry is that once the decomposition starts, it will be impossible to stop….

January 2012: Arctic Sea Ice predicted to be gone by 2015

(Reprinted from Arctic-News Blogspot) The ice in the Arctic is thinning (in a 1990 paper in Nature (2), showing a 15% thickness loss in 11 years), and recent work from UK and US submarines now shows a loss of more than 43% in thickness between the 1970s and 2000s, averaged over the ocean as a whole (3). Since 1979, the volume of Summer Arctic Sea Ice has declined by a staggering 80% in volume. This is an enormous loss – nearly half of the ice thickness – and has changed the whole appearance of the ice cover. Most of the ice is now first-year rather than the formidable multi-year ice which used to prevail.

The thinning is caused by a mixture of reduced growth in winter, because of warmer temperatures and more heat in the underlying water column, and greater melt in summer. A change in the direction and speed of ice motion has also played a role, with the ice departing quicker from the Arctic Basin through Fram Strait rather than circulating many times inside the Arctic.The summer (September) area of sea ice reached a record low in 2007, almost matched in 2011, but what is most serious is that the thinning continues. It is inevitable that very soon there will be a downward collapse of the summer area because the ice will just melt away. Already in 2007, measurements indicated that during the summer there were 2 metres of melt off the bottom of of ice floes in the Beaufort Sea, while the neighboring first-year floes had only reached in 1.8 metres during winter – so all first-year ice was disappearing. This effect will become more important and will spread throughout the Arctic Basin.

Figure 14 : Arctic sea ice volume decline graph by Wipneus based on PIOMAS data.

 

Arctic Sea Ice Collapse from 1979 to 2012 (Data source:  Pan-Arctic Ice Ocean Modeling and Assimilation System – PIOMAS)

March 2012 Study: NASA Methane Levels above the Arctic show Dramatic Rise

As the polar projection below shows, extremely high levels of methane are concentrated above the East Siberian Arctic Shelf (ESAS). These correlate well with Dr. Igor Semiletov,  Dr. Natalia Shakhova ‘s observations of large methane plumes in ESAS

Figure 15A: Arctic Methane Levels in Nov 2002

Figure 15B: Arctic Methane Levels in Nov 2010

Figure 15C: Arctic Methane Levels in Nov 2011

Figure 15D: Arctic Methane Levels in Mar 2012

Figure 16: CH4 Levels in Northern Hemisphere (NH), Southern Hemisphere (SH) and Global Average (Source: NASA)

May 2012 Study: Katey Walter Anthony et al. Measure Ancient Methane Outgassing as Permafrost Recedes

Figure 17: Methane escaping from pockets near receding Permafrost (Source: Nature Geoscience)
Katey Walter Anthony’s latest published study (Nature Geoscience, May 2012)  ring the alarm bell yet again, providing clear evidence that we are approaching the Permafrost tipping point.  During the winters of 2008 to 2010, Anthony and her team flew across the state of Alaska — from the Kenai Peninsula to the North Slope and also hiked across lakes in Greenland during the winter of 2010. Altogether, they surveyed nearly 7,000 lakes from the air, identifying 77 of them as likely sites where methane was seeping. The researchers then visited 50 of the lakes to confirm the presence of seeps and take samples of the gas boiling up from the floor. Using this combination of aerial and ground-based surveys, the team identified approximately 150,000 methane seeps in both Alaska and Greenland in lakes along the margins of ice cover. They later tested the samples and were able to identify ancient methane by observing the ratio of different isotopes of carbon in the methane molecules.  

This established the gas’s source as ancient and geologic, rather than the result of decaying organic material. This is important because it reveals a new source of methane. The retreat of Arctic permafrost and glaciers often reveal previously frozen organic matter which subsequently decays and releases huge amounts of methane; this much was already known. The Anthony study reveals a new source of methane outgassing, methane from geologic sources such as coal beds and natural gas deposits which have been kept in place by a cryosphere cap of glaciers, permafrost and icesheets.  “Now we are saying that as permafrost thaws and glaciers retreat it is going to let something out that has had a lid on it,” said University of Alaska Fairbanks researcher Katey Walter Anthony. “We observed most of these cryosphere-cap seeps in lakes along the boundaries of permafrost thaw and in moraines and fjords of retreating glaciers,” write the authors, clearly correlating anthropogenic warming in the Arctic with the release of this ancient methane store. “When the glaciers retreat or the permafrost thaws,” Walter Anthony said, “it creates conduits for deeper gas to make its way up through the Earth.” And those conduits could become more widespread if worldwide temperatures continue to increase, Walter Anthony notes. “In a warmer world, thawing permafrost and wastage of glaciers and ice sheets could lead to a significant transitional degassing of subcap methane.” “If this relationship holds true for other regions where sedimentary basins are at present capped by permafrost, glaciers and ice sheets, such as northern West Siberia, rich in natural gas and partially underlain by thin permafrost predicted to degrade substantially by 2100, a very strong increase in methane carbon cycling will result, with potential implications for climate warming feedbacks.”

June 19, 2012 Review of Methane Mitigation Technologies with Application to Rapid Release of Methane from the Arctic

In their June 19 paper published in Environmental Science Technology,  Joshuah K. Stolaroff et al. review mitigation technologies developed for anthropogenic sources which can be adopted to deal with Arctic sources. The authors also review the current estimates of types of sources, where they are and their estimated magnitudes in a table nicely summarized by the Arctic News blogspot.

Table 1: Summary of Arctic Methane Sources (Source Arctic News, Original Source Stolaroff et al.,

Review of Methane Mitigation Technologies with Application to Rapid Release of Methane from the Arctic (1 Tg = 1 milion metric tonne)

Figure 18: NOAA All Land Total CO2 Emissions 2001 to 2010 in Gt/year = Pg/year (Source: NOAA Carbon Tracker)

Stolaroff et al. acknowledge that there are major gaps in understanding the mechanisms, magnitude, and likelihood of rapid methane release from the Arctic. Their summary of the potential amount of methane sources in the Arctic is nonetheless disturbing. While NOAA information shows a mean CO2 emission level of about 10 Gt/year from all land sources, Stolaroff et al. show that there is nearly 7,000 Gt of trapped methane in the Arctic. Therefore, Arctic warming that releases only a small percentage can have profound impact on global warming. Dr Semiletov’s June 2011 observations of giant plumes of methane outgassing would suggest large amounts of outgassing is already underway and that further research is a matter of urgency.

Sept 16, 2012 Arctic Sea Ice sets New All time Low

If you calculate how much heat went into the Arctic Ocean in the summer of 2012 in the areas where there used to be ice, it’s about enough energy to power the United States for 25 years. 

- Dr. Jennifer Francis, Rutgers University

Figure 19: Arctic sea ice on Sept 16, 2012 (Source: NSIDC)

The National Snow and Ice Data Center reported on Sept 19, 2012 that the Arctic sea ice had reached an alltime low. The sea ice extent dropped to 3.41 million square kilometers (1.32 million square miles). The 2012 minimum was 760,000 square kilometers (293,000 square miles) below the previous record minimum extent in the satellite record, which occurred on September 18, 2007.  This is an area about the size of the state of Texas. The September 2012 minimum was in turn 3.29 million square kilometers (1.27 million square miles) below the 1979 to 2000 average minimum, representing an area nearly twice the size of the state of Alaska. This year’s minimum is 18% below 2007 and 49% below the 1979 to 2000 average. The orange line in the map shows the 1979 extent of the sea ice.  Overall there was a loss of 11.83 million square kilometers (4.57 million square miles) of ice since the maximum extent occurred on March 20, 2012, which is the largest summer ice extent loss in the satellite record, more than one million square kilometers greater than in any previous year.

The Arctic sea ice has not only surface area but also thickness. Most of the thick ice has vanished and only thin ice remains. The Arctic ocean has lost 80% of its sea ice volume, as measured both by satellite and submarine sonar. The remaining thin ice is very vulnerable. (Source: NSIDC)

Figure 20: Relative amount of Arctic sea ice lost from 1980 to 2007 (Source: Dr. Jennifer Francis, Rutgers University)

Oct 24, 2012 Recent Changes to the Gulf Stream Causing Widespread Gas Hydrate Destabilization

In the study Recent changes to the Gulf Stream causing widespread gas hydrate destabilization published in the Oct 24, 2012 edition of Nature, geophysicist Matt Hornbach of SMU’s Huffington Department of Earth Science used a combination of seismic data and thermal models to show that recent changes in intermediate-depth ocean temperature associated with the Gulf Stream are rapidly destabilizing methane hydrate along a broad swathe of the North American margin. The study found that the area of active hydrate destabilization covers at least 10,000 square kilometres of the United States eastern margin, and occurs in a region prone to kilometre-scale slope failures. Previous hypothetical studies, postulated that an increase of five degrees Celsius in intermediate-depth ocean temperatures could release enough methane to explain extreme global warming events like the Palaeocene–Eocene thermal maximum (PETM) and trigger widespread ocean acidification. Hornbach’s team performed analysis that suggests that changes in Gulf Stream flow or temperature within the past 5,000 years or so are warming the western North Atlantic margin by up to eight degrees Celsius and are now triggering the destabilization of 2.5 gigatonnes of methane hydrate (about 0.2 per cent of that required to cause the PETM). In itself, this is not enough to trigger a tipping point, however it is unlikely that the western North Atlantic margin is the only area experiencing changing ocean currents and the teams estimates may therefore represent only a fraction of the methane hydrate currently destabilizing globally. Co-author Ben Phrampus told NBC News that the wider destabilization evidence includes data from the Arctic and Alaska’s northern slope in the Beaufort Sea. Some Arctic land area are seeing permafrost thaw, which could release methane stored there as well. Indeed some experts are suggesting that methane could become a bigger climate factor than carbon dioxide. Jurgen Mienert, the geology department chair at Norway’s University of Tromso, told NBC News “We may approach a turning point” from a warming driven by man-made carbon dioxide to a warming driven by methane. “The interactions between the warming Arctic Ocean and the potentially huge methane-ice reservoirs beneath the Arctic Ocean floor point towards increasing instability,” he added.  He noted, however, that “one of the big unknowns is the magnitude of rapid methane escape from the ocean floor, and how natural filter systems react and affect the future ocean, its environment and the climate.” In the figures below, the presence of methane hydrates or clathrates at a given site is often determined by observation of a “bottom simulating reflector” (BSR), which is a seismic reflection at the sediment to clathrate stability zone interface caused by the unequal densities of normal sediments and those laced with clathrates.

Figure 21:  a, Study area, shown boxed in the map-view inset, where the location of the Gulf Stream is also shown (dashed black lines), flowing along the western edge of the North Atlantic margin12. In the main figure, the grey area denotes where BSRs exist below the sea floor21; the pink area is where methane hydrate is destabilizing owing to recent changes in ocean temperature; and the approximate location of the Gulf stream is between the two solid black arrows. b, Multi-channel seismic line 80.A is one of several seismic lines in the region showing clear BSRs shoaling westward along the edge of the continental margin29. The rectangle indicated in white is shown magnified in the inset. Inset, the gas hydrate phase boundary (that is, BSR) shows as a strong, negative polarity reflector (black arrows) that behaves erratically with depth beneath sea-floor less than ~1,000 m.b.s.l. (Source: Nature)   Figure 22: a, Two different ocean temperature regimes exist in the western North Atlantic, with Gulf Stream temperatures as much as 8 ± 1.1 °C (1σ error) warmer at intermediate water depths than ocean temperatures outside the Gulf Stream. Seismic line 80.A was acquired within the Gulf Stream, yet the predicted BSR depth using present day (Gulf Stream) ocean temperatures is shallower than observed BSR depths for sea-floor depths less than ~1,000 m.b.s.l. (b). Comparison between observed and predicted BSR depths for the two ocean temperature regimes indicate cold, non-Gulf Stream intermediate ocean temperatures produce a much better fit to observed BSR depths (c). This implies recent ocean warming or northwest intrusion of the Gulf Stream along the Carolina rise and the onset of methane hydrate destabilization along the margin. This observation is widespread (Supplementary Information). Dashed yellow lines indicate where the BSR is inferred but difficult to identify clearly in seismic data. (Source: Nature)  

 Figure 23: To place first-order constraints on the timing of ocean temperature warming and methane hydrate dissociation along line 80.A, we run a time dependent diffusive heat-flow forward model in which we start initially with our steady-state cold ocean temperature model result (Fig. 2c), but instantaneously change the ocean temperature boundary condition to present day (Gulf Stream) values. The resulting forward model shows evolution of hydrate stability and BSR depth through time. Each coloured line represents a model-predicted BSR location in the future. These results indicate that dissociation will continue for the next several thousand years if no change in ocean temperature occurs. The pink zone represents the total area of destabilizing methane hydrate. (Source: Nature)

Jan 13, 2013 – PNAS Permafrost Resesarch – Newly Exposed Dissolve Organic Carbon (DOC) has 40% > Succeptible to Microbial Conversion to CO2 when exposed to UV light in Sunlight than when Kept Dark

Researcher Rose Cory of the University of North Carolina has published a paper in the Jan 2013 edition of the Proceedings of National Academy of Science entitled  Surface exposure to sunlight stimulates CO2 release from permafrost soil carbon in the Arctic in which her research team’s finding show that  sunlight increases bacterial conversion of exposed soil carbon into carbon dioxide gas by at least 40 percent compared to carbon that remains in the dark. Cory and her team study a sample of failed thermokasts around Toolik, Alaska. These geological formations have become mechanically unstable due to the melting permafrost, exposing ancient carbon stores to the surface. Their studies show that microbial CO2 is released to the atmosphere at rates 40% faster when exposed to sunlight than when in the dark.  Cory says “This really changes the trajectory of the debate” . Cory and her research team are performing further research to try to come up with an estimate of how much and how quickly CO2 will be released due to this mechanism.
Soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to surface waters. Once exposed, the fate of this C is unknown but will depend on its reactivity to sunlight and microbial attack, and the light available at the surface. In this study we manipulated water released from areas of thermokarst activity to show that newly exposed DOC is >40% more susceptible to microbial conversion to CO2 when exposed to UV light than when kept dark. When integrated over the water column of receiving rivers, this susceptibility translates to the light-stimulated bacterial activity being on average from 11% to 40% of the total areal activity in turbid versus DOC-colored rivers, respectively. The range of DOC lability to microbes seems to depend on prior light exposure, implying that sunlight may act as an amplification factor in the conversion of frozen C stores to C gases in the atmosphere.

NBC Report on Permafrost melting in the North

Assistant Professor Rose Cory of University of North Carolina films a Thermokast – Permafrost that has melted and given way

Figure 24: In thermokarst impacted sites (Left), water exposed to natural sunlight stimulated bacterial activity by 46.8% (white versus black bars), whereas in corresponding reference sites the mean response was to decrease bacterial activity by −13.7% (single-factor ANOVA, P = 0.0008, n = 11, SE of three replicate samples for each bar for each site are shown).  
Figure 25: Percent difference between bacterial activity grown in light-exposed versus dark water plotted against the normalized moles of photons absorbed (photobleaching, integrated from 305 to 395 nm) in each thermokarst sample and its adjacent reference site. This illustrates that the extent of photobleaching controls the amplification of bacterial activity by light. SE bars are from three replicates for each sample or treatment; some error bars are hidden by the symbol. Ordinary least squares regression of percent change in bacterial activity versus photobleaching, R2 = 0.72, n = 6, P = 0.03.

Jan 1 to 31, 2013 – Rapid Methane Rise from Jan 1, 2013 to Jan 31, 2013

Figure 26: Dramatic  year-on-year increases of methane levels above the Arctic Ocean in the same period Jan 21-31 from 2009 to 2013 (Source: Dr. Leonid Yurganov and Arctic News blog)

 

Figure 27: Dramatic increases of methane levels above the Arctic Ocean in the course of January 2013 in a large area north of Norway:  January 1-10, 2013  (left), January 11-20, 2013 (center) and January 21-31, 2013 (right) (Source: Dr. Leonid Yurganov and Arctic News blog)

  
  

Figure 28 : Arctic sea ice concentration with methane concentration overlay (Source : Arctic News blog)

Overlaying methane measurements with sea ice concentrations shows that the highest levels of methane coincide with areas in the Arctic Ocean without sea ice. Sea ice is declining at exponential pace. The big danger is that a huge rise of temperatures in the Arctic will destabilize huge amounts of methane currently held in the seabed. Comprehensive and effective action is needed now to avoid catastrophe.

Dr. Malcolm Light kindly provided the following comments on the image at the top of this post:

The first image clearly shows that the westerly Svalbard branch of the Gulf stream must be destabilizing methane hydrates between Norway and Svalbard. The effects of the eastern Yermack branch of the Gulf stream which enters the Barents Sea is clearly seen in the third figure and methane hydrates in the whole Barents Sea region are clearly being destabilized by the heat it is bringing in. All this extra heating of the Gulf Stream causing increased evaporation is the reason for the giant flooding that has been seen in Europe and the water clouds are preventing the ocean from losing its heat efficiently so the Yermack and Svalbard branches can still destabilize the methane hydrates even in the dead of winter.

Feb 21, 2013, Paper claims 1.5 Degree C is the Critical Temperature for Triggering Permafrost Feedback Effects

vaks fig 1

Figure 29: Map showing the extent of permafrost types in eastern Siberia, the Gobi Desert, and the location of studied caves (black circles). Permafrost data are taken from Brown et al. (2001) (29). (Source: Sciencexpress Reports)

A Feb 21, 2013 research letter published in Sciencexpress called Speleothems Reveal 500,000-Year History of Siberian Permafrost conducted by a team of researchers led by Oxfords’ Dr. Anton Vaks, concluded that paleoclimatological evidence indicates that permafrost melting today may begin at 1.5 Deg C. Dr. Vaks and his colleagues studied cave carbonates called speleothems, mineral formations more commonly know as stalactites and stalagmites and used a well known archeological dating tool called U-T (Uranium Thorium) to determine when past permafrost melt events occurred. The team gathered data from a series of six caves in Northern Siberia, specifically along a north/south transect to determine just how far north global warming temperatures in the past reached – for example, how far north would a 1 Deg C or a 1.5 Deg C rise in global mean temperature travel?

The team collected 36 samples from the caves and used the U-Th, or Uranium / Thorium paleoclimatological dating techniques to date the formations over a period of 500,000 years.  Stalactites and stalagmites form during periods of gradual melting, when meltwater dripped into the caves and  stop growing when there is no water. The speleothem formation can therefore be used as a proxy for permafrost melting. Rapid speleothem growth is an indication of signficant permafrost melting and when slow or no growth at a particular time period is an indication of stable permafrost. The team compared the growth of speleothems to other temperature records going back 500,000 years. They found that:

  1. The youngest speleothem growth in the region of modern continuous permafrost (i.e., at 60°N lattitude) occurred during interglacial MIS-11 (424,000 and 374,000 years ago)
  2. Speleothems grew during all interglacial periods (Fig. 2, A and B) in the central regions of the transect
  3. Age ranges in southern Siberia also demonstrate that the duration of speleothem deposition in MIS-11 was longer than during subsequent interglacials

These observations indicate that permafrost thawing during MIS-11 was more extensive than at any other point during the last 450,000 years and extended as far northward as 60°N – significantly further north than the present limit of continuous perma-frost.

For a period of about 120,000 years, the temperatures in the region investigated were between 0.5 to 1 Deg C higher than today. The team found that during that time:

  • stalactites in caves further south, near Lake Baikal, grew and therefore were indicative of melting permafrost
  • stalactites in the far northern Ledyanaya Lenskaya cave, near the town of Lensk at latitude 60N did not grow and therefore indicative that the permafrost remained stable at those temperatures

During MIS-11, 400,000 years ago, temperatures were 1.5 Deg C higher than in pre-industrial times and the stalactites in the far northern cave on the boundary of continuous permafrost region grew

“This indicates that 1.5 Deg C appears to be something of a tipping point,” said Vaks. At present, global average temperatures are about 0.85 C above pre-industrial levels. So instead of the 2 Deg C target which the IPCC has set, which implies a safe budget of another 1.15 Deg C, in light of this study, that safe budget has suddenly been reduced to 0.65 Deg C. As if this were not disconcerting enough, another study released in Nov 24, 2013 narrows this budget even further.

speleothem cross-section example gly.uga.edu
Figure 30: Example of cross-section of speleothem (Source: University of Georgia)

Scientists can measure the growth and halting of stalactite and stalagmites by cutting through their cross-sections. As the water drips down from the cave roof and calcifies, it forms layers. Hence stalactites form layers, with the oldest being near the roof and the youngest at the tip. For stalagmites, it’s the same, except the tip is inverted – at the top, while the oldest layer at the bottom of the cave floor.

Scientists also use the Marine Isotope Stage (MIS) for measuring time spans using oyxgen isotopes during the Quartenary period (the last 2.6 million years).

Growing stalactite or stalagmite in permafrost regions is used as a proxy indication that permafrost was melting during that time in history. This result is extrapolated to today, to indicate that these regions could thaw once again if temperatures today rise to similar levels as in the past.

A good reference for how scientists use speleothems to provide clues about the earth’s climate past can be found here at this NASA paleoclimatology page.

 

vaks fig 2

Fig. 31. (A) Distribution of speleothem U-Th (Uranium-Thorium dating) ages (±2σ) in time and space (n – total number of U-Th age determinations per cave, including those beyond the U-Th range) with grey bars signifying periods of growth in Okhotnichya and Botovskaya caves. (B) Benthic δ18O stack (30) with MIS numbers. (C) Concentration of biogenic silica in Lake Baikal sediments (%) (23). (D) Pacific Warm Pool Mg/Ca SST, with the pre-industrial Late Holocene SST shown by red horizontal fragmented line (20, 21). (E and F) CH4 and CO2 records of EPICA Dome C respectively (25, 26). (G) Summer insolation at 55°N (28). Speleothems with ages exceeding 500 ka (within ±2σ range) are not shown, but accounted for in n. Two samples SLL9-2-A+B and SOP-32-B are not included because they reflect a mixture of material from different layers; please refer to table S1. (Source: Sciencexpress Reports)

vaks fig 3

Fig. 32. Siberian speleothem growth periods during Holocene and MIS-5.5 (A) with grey bars indicating periods of growth. Compared with East-Asian Monsoon record from Hulu and Sanbao caves (B) (31), GICC05 δ18O (C) (32, 33), CH4 (D) and CO2 (E) records of EPICA Dome C (25, 26), and 55°N summer insolation (F) (28). (Source: Sciencexpress Reports)

Mar 10, 2013, Arctic Warming causing Increased Plant Growth in the North

Figure 33: Vegetation index tracking changes of plant growth over large northern areas (Source: NASA Goddard Space Flight Center Scientific Visualization Studio)

 April 11, 2013 – Arctic Sea Ice Death Spiral

Many experts now say that if recent volume trends continue we will see a “near ice-free Arctic in summer” within a decade. And that may well usher in a permanent change toward extreme, prolonged weather events “such as drought, flooding, cold spells and heat waves.” It will also accelerate global warming in the region, which in turn will likely accelerate both the disintegration of the Greenland ice sheet as well as the release of the vast amounts of carbon currently locked in the permafrost, which in turn will likely add 0.4°F – 1.5°F to total global warming by 2100. (Source: Thinkprogress)

Arctic sea ice appears to be headed for complete dissappearance by 2016. If this is true, we will probably have triggered irreversible tipping points. The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this view of extensive sea-ice fracturing off the northern coast of Alaska. The event began in late-January and spread west toward Banks Island throughout February and March 2013. The Arctic sea ice volume is represented in a new infographic by creative tech guru Andy Lee Robinson, who shows that “death spiral” is the right visual metaphor:
Figure 34: PIOMAS Ice Volumes

June 17, 2013 – Alaska reaches 36 Deg. C in June and Rare Cloudless Day in Alaska

The picture below seems to capture an ordinary scene at the beach.

arctic sunbathing

Figure 35: Cloudless day in Alaska on June 17, 2013 (Source: NASA)

 NASA said that the same ridge of high pressure that cleared Alaska’s skies also brought stifling temperatures to many areas accustomed to chilly June days. Talkeetna, a town about 100 miles north of Anchorage, saw temperatures reach 96°F (36°C) on June 17. Other towns in southern Alaska set all-time record highs, including Cordova, Valez, and Seward. The high temperatures also helped fuel wildfires and hastened the breakup of sea ice in the Chukchi Sea. Scientists suspect what is happening is that the changing climate is affecting the pattern of the jet stream, causing warmer high-pressure systems to sit and stay in one place in what’s called a blocking pattern. The high pressure “heat dome” over Alaska is simlar to the one that caused Greenland to melt extensively in 2012. Weather patterns are changing because the climate is changing. The Arctic climate system in evidently undergoing a rapid evolution due to changing conditions there and positive feedback effects are beginning to affect each other in ways the models could not predict. All of this will accelerate warming beyond the predictions of the models.

June 27, 2013 – Permafrost Tipping may be reached at 1.5°C ± 0.5 above the pre-industrial level

In a study led by researcher Gideon Henderson at the University of Oxford’s Department of Earth Sciences, scientists have come to the conclusion that 1.5°C ± 0.5 of warming above pre-industrial time may be a tipping point for widespread permafrost melting, releasing vast amounts of Carbon into the atmosphere. The scientists came to this conclusion after studying the records of speleothems (such as stalactites and stalagmites), geological structures which form when water seeps through cracks in cave walls, dissolving minerals which precipitate in the air filled cave. The speleothems Henderson’s team studied were found in Ledyanaya Lenskaya Cave, Eastern Siberia. These structures form when it is above 0 °C  and stop when at or below 0 °C . Lead author Anton Vaks says that cave temperatures usually approximate the local mean annual air temperature so knowing the cave temperature when they were actively growing can determine the mean annual air temperature outside. By applying radiocarbon dating, the team was able to show that the speleothems actively grew during two periods: 400,000 BC and 1 million BC. These periods have been correlated with temperatures that are 1.5°C ± 0.5 of warming above pre-industrial time.  Global temperatures are currently around 0.7 °C above pre-industrial level and current models suggest that a warming of 1.5°C ± 0.5 will be achieved within 10-30 years.

July 21-23, 2013 – Siberia Heat Wave and Methane Pulse

 

nasa-earth-observatory-july-2013-siberia-wildfire

Figure 36: Siberia wildfires from Arctic heat wave (Source: NASA)

In July of 2013, a heat wave hit Siberia. A high pressure dome caused wildfires across Siberia. This followed fires in 2012 which burned roughly 74 million acres of Russian forests, Typically, large wildfires burn on the southern fringe of the taiga, a dense forest ecosystem also known as the Boreal forest. The Boreal forests make up  nearly 10 percent of the planet’s land surface and contain more than 30 percent of the carbon that is stored on land, in plants and soils. Globally, the boreal forest covers 6.41 million square miles, forming a ring along and just below the Arctic Circle.

boreal-forest-wikimediaFigure 37: Boreal Forest (source: Wikimedia)

Theses fires are burning in a more central portion of the taiga. According to NASA researchers, the number of taiga wildfires is expected to double by the end of the century.

A recent PNAS study of taiga wildfires in Alaska found that these forests are burning at the highest rate in at least the past 10,000 years and will continue to grow worse. The increased buring of Boreal forests increases CO2 emissions in a number of ways:

  • Stored carbon has been freed from these ecosystems
  • Black carbon emitted from the fires can land on snow and ice in the Arctic, lowering albedo and accelerating the warming of ice packs

July 24, 2013 – Nature Climate Change Letter – The Arctic Economic Time Bomb

There is a steep global price tag attached to physical changes in the Arctic.

- Whiteman et al.

Rome is burning and the world is still fiddling. Rome, in this case is the global climate system and in particular, the cryosphere. On July 24, 2013, Gail Whiteman, from Erasmus University; Chris Hope, Reader in Policy Modelling at Cambridge Judge Business School, University of Cambridge; and Peter Wadhams, Professor of Ocean physics at the University of Cambridge wrote a groundbreaking comment for Nature entitled Climate science: Vast costs of Arctic change which performs an analysis of the economic impact to the world if a very isolated Arctic region called the East Siberian Arctic Shelf were to release methane hydrates currently trapped in shallow underwater deposits and kept there by cold Arctic conditions. The authors open with this statement:

Unlike the loss of sea ice, the vulnerability of polar bears and the rising human population, the economic impacts of a warming Arctic are being ignored. Most economic discussion so far assumes that opening up the region will be beneficial. The Arctic is thought to be home to 30% of the world’s undiscovered gas and 13% of its undiscovered oil, and new polar shipping routes would increase regional trade12. The insurance market Lloyd’s of London estimates that investment in the Arctic could reach US$100 billion within ten years3. The costliness of environmental damage from development is recognized by some, such as Lloyd’s3 and the French oil giant Total, and the dangers of Arctic oil spills are the subject of a current panel investigation by the US National Research Council. What is missing from the equation is a worldwide perspective on Arctic change. Economic modelling of the resulting impacts on the world’s climate, in particular, has been scant. We calculate that the costs of a melting Arctic will be huge, because the region is pivotal to the functioning of Earth systems such as oceans and the climate. The release of methane from thawing permafrost beneath the East Siberian Sea, off northern Russia, alone comes with an average global price tag of $60 Trillion USD in the absence of mitigating action — a figure comparable to the size of the world economy in 2012 (about $70 trillion). The total cost of Arctic change will be much higher.
The team used the Page09 Climate Assessment model to assess the economic damage that a release of 50-gigatonne (Gt) reservoir of methane stored in the form of hydrates on the shallow East Siberian Arctic Shelf would have. The methane is likely to be emitted as the seabed warms, either steadily over 50 years or suddenly. The model calculates the impacts of climate change and the costs of mitigation and adaptation measures.

Figure 38: Three methane pulse scenarios (Source: Nature Comment)

The team superposed a decade-long pulse of 50 Gt of methane, released into the atmosphere between 2015 and 2025 and ran the model 10,000x to calculate confidence intervals and to assess the range of risks arising from climate change until the year 2200. The model takes into account:

  • sea-level changes
  • economic and non-economic sectors (ie. food and freshwater security impacts)
  • discontinuities such as the melting of the Greenland and West Antarctic ice sheets

Three scenarios were analyzed for economic impact. When looking at these cases, bear in mind that the current global economy is valuated at $70 Trillion USD. Scenario 1: Business-As-Usual (BAU) – Increasing emissions of CO2 and other greenhouse gases with no mitigation action (the scenario used by the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A1B)

  • Shifts the time when we exceed the 2°C by nearer by 15-35 years: from to (2050 – 2070) to 2035
  • Mean total predicted cost of climate-change impacts of BAU = $400 trillion; additional cost due to Arctic methane release = $60 Trillion (net present value) – an additional 15%

Scenario 2: Low Emission trajectory – A 50% chance of keeping the rise in global mean temperatures below 2°C (the 2016r5low scenario from the UK Met Office)

  • shifts the time when we exceed the 2°C by nearer by 15-35 years: from to (2055 – 2075) to 2040
  • Mean net present value of global climate-change impacts is $82 trillion; additional cost due to Arctic methane pulse = $37 Trillion (net present value) – an additional 45%
Scenario 3: A 25Gt pulse instead of a 50 Gt pulse
  • A pulse of 25 Gt of methane has half the impact of a 50 Gt pulse
Other findings include: These costs remain the same irrespective of whether the methane emission is delayed by up to 20 years, kicking in at 2035 rather than 2015, or stretched out over two or three decades, rather than one

  • The economic consequences will be distributed around the globe, but the modelling shows that about 80% of them will occur in the poorer economies of Africa, Asia and South America
  • The extra methane magnifies flooding of low-lying areas, extreme heat stress, droughts and storms
  • The full impacts of a warming Arctic, including ocean acidification and altered ocean and atmospheric circulation, will be much greater than the studies cost estimate for methane release alone
  • To find out the actual cost, better models are needed to incorporate feedbacks that are not included in PAGE09, such as:
    • linking the extent of Arctic ice to increases in Arctic mean temperature, global sea-level rise and ocean acidification
    •  including estimates of the economic costs and benefits of shipping
    • Oil-and-gas development in the Arctic should take into account the impacts of black carbon, which absorbs solar radiation and speeds up ice melt, from shipping and gas flaring
  • Splitting global economic impact figures into countries and industry sectors would raise awareness of specific risks, including:
    • the flooding of small-island states or coastal cities such as New York, Florida, South-east Asia or Island states by rising seas
    • Mid-latitude economies such as those in Europe and the United States could be threatened by a suggested link between sea-ice retreat and the strength and position of the jet stream, bringing extreme winter and spring weather. Unusual positioning of the jet stream over the Atlantic is thought to have caused this year’s protracted cold spell in Europe

Finally, the team concludes by saying:

It will be difficult — perhaps impossible — to avoid large methane releases in the East Siberian Sea without major reductions in global emissions of CO2. Given that the methane originates in local seabed warming, then reducing black carbon deposits on snow and ice might buy some precious time. But unknown factors could also mean that our impact estimates are conservative. Methane emerging in a sudden burst could linger for longer in the atmosphere, and trigger more rapid temperature changes than if the gas were released gradually.

Nov 24, 2013 – A new target – even lower than 1.5 Deg C

Our study shows that global mean temperature may even increase after zero carbon emissions, because of feedback effects arising in response to the magnitude and geographic structure of ocean heat uptake. Thus, estimates of allowable carbon emissions required to remain below the 2 C global warming target may be significantly lower than previously thought. A better understanding and monitoring of how ocean circulation changes impact regional ocean heat uptake and thus efficacy is necessary to narrow uncertainties in climate change projections.

- Thomas Lukas Frölicher,, ETH Zurich

In Feb 2013, paleoclimatic research of speleothems in Northern Russia done by Anton Vaks et al. concluded that permafrost in the far northern latitudes of 60 Deg and above can begin melting at temperatures as low as 1.5 Deg C above pre-industrial times. A team from Princeton led by researcher Thomas Frölicher released a paper in Nov 24, 2013 entitled Continued global warming after CO2 emissions stoppage which will likely reduce the safe temperature figure of Vaks significantly lower.

Frölicher and his team used computer models to determine how global temperatures responded to a complete 100% stoppage of anthropogenic emissions and came to the conclusion that the large amount of heat-trapping emission already in the atmosphere would continue heating it for centuries to come. Frölicher’s work contradicts the scientific consensus that upholds that global temperature would remain constant or decline if emissions were suddenly cut to zero. Frölicher and his colleagues discovered that oceans’, especially polar oceans gradually lose their ability to absorb heat from the atmosphere – a mechanism previous research had not accounted for. In effect, there is a battle going on between two opposing forces:

Warming Effect

  1. oceans decrease their heat uptake
  2. feedback effects arising in response to the geographic structure of ocean heat uptake

Cooling Effect

  • decreasing atmospheric CO2

and over mult-century time scales, the computer model shows that there is a net heating rather than global temperatures remaining costant or a net cooling.

Currently, human civilization has emitted approximately 500 Gigatons into the atmosphere and the upper limit of safe emissions has been calculated at approximately 1000 Gigatons. The current estimated allowable carbon emissions safety budget to 2050 is another 565 Gigatons and in light of this study, this needs to be revised.

“If our results are correct, the total carbon emissions required to stay below 2 degrees of warming would have to be three-quarters of previous estimates, only 750 billion tons instead of 1,000 billion tons of carbon,” said Frölicher. Suddenly, in light of Vaks and Frölicher’s studies, our safety budget has been trimmed dangerously low.

  1. IPCC original safe global temperature target above pre-industrial time = 2 Deg C
  2. Current global temperature increase since pre-industrial times = 0.85 Deg C
  3. Current safety margin = 2 Deg C – 0.85 Deg C = 1.15 Deg C
  4. Vaks-revised safe global temperature target above pre-industrial time = 1.5 Deg C
  5. Current global temperature increase since pre-industrial times = 0.85 Deg C
  6. Vaks-revised safety margin = 1.5 Deg C – 0.85 Deg C = 0.65 Deg C

If we add Frölicher’s findings to Vaks already lowered target, we know that we must limit the maximum temperature below even Vak’s 1.5 Deg C to prevent irreversible permafrost melting. The 0.65 Deg C buffer temperature based on Vak’s calculation must, in light of Frölicher et al.  be lowered significantly.

Even though Frölicher’s results predict warming to occur over multi-century scale, if that future warming combined with the current warming exceeds Vak’s 1.5 Deg C, the permafrost will be almost guaranteed to melt some centuries in the future. All of a sudden, we have come perilously close to triggering a future, irreversible permafrost melting scenario and our ability to cut carbon emissions radically today takes on a whole new sense of urgency.

Dec 2013 – NOAA Arctic Report


Summer surface air temperatures were particularly low across the central Arctic Ocean, northern Canada and Greenland relative to 2007-2012 (a period of pronounced summer sea ice retreat), and were somewhat lower than the long-term average of 1981-2010. 
Minimum sea ice extent in September 2013 exceeded the record low of 2012, but was the 6th lowest since observations began in 1979 despite the relatively cool summer of 2013. The seven lowest minimum ice extents have occurred in the last seven years, 2007-2013.
Large land mammals convey a mixed message, with muskoxnumbers stable/increasing since the 1970s, while many caribou and reindeer herds currently have unusually low populations for the period 1970-2013.
Snow extent in May 2013 reached a new record low in Eurasia, while Northern Hemisphere-wide snow extent was below average for spring (April, May, June).
Arctic tundra vegetation greenness (a measure of productivity) and growing season length have continued to increase since observations began in 1982
Changes in fish and bottom dwelling organisms include continued northward migration of species not previously seen in the Arctic.

Feb 14, 2014 – Discovery of a novel methanogen prevalent in thawing permafrost

Methanoflorens stordalenmirensis seems to be a indicator species for melting permafrost. It is rarely found where there is permafrost, but where the peat is warmer and the permafrost is melting we can see that it just grows and grows. It is possible that we can use it to measure the health of mires and their permafrost. The recently documented global distribution also shows, on a much larger scale, that this microbe spreads to new permafrost areas in time with them thawing out. This is not good news for a stable climate  

- Researcher Rhiannon Mondav, Uppsala University

Abstract:

Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus ‘Methanoflorens stordalenmirensis’ gen. nov. sp. nov., belonging to the uncultivated lineage ‘Rice Cluster II’ (Candidatus ‘Methanoflorentaceae’ fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, ‘Methanoflorentaceae’ are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus ‘M. stordalenmirensis’ appears to be a key mediator of methane-based positive feedback to climate warming.

In Sweden, permafrost at the Stordalen mire has melted quickly over the past three decades and emitted increasing amounts of methane. An international team of researchers decided to study the melting permafrost, collecting samples of peat, water and air for a number of years. Uppsala University PhD student Rhiannon Mondav analysed the peat samples and discovered a previously unknown methanogen and with her colleagues, mapped its genome and named it Methanoflorens stordalenmirensis. They also discovered that this microbe was a special type of methanogen called a hydrogenotrophic, which uses carbon dioxide (CO2) as a source of carbon, and hydrogen as a reducing agent. 

“DNA fragments from this microbe have been found over the last 20 years, but no one knew what it did or who its closest ancestors were. What we have done is to figure out what it does and who it is related to”, says  Mondav.

Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic (aquatic environment with 0% dissolved oxygen) conditions. Methanogens  are classified as archaea, a domain distinct from bacteria and are found in wetlands, responsible for marsh gas as well in the intestinal tracts of humans and ruminants where they cause flatulence and belching respectively. Once identified, the team found it is ubiquitous throughout the world in other peatlands and mires. It thrives in the acid peatlands with annual cycles of freezing, melting, flooding and drought.

Discovery of a novel methanogen prevalent in thawing permafrost ncomms4212-f3

 

Figure 39: Locations of the newly discovered Methanoflorens stordalenmirensis (Source: Nature)

When they looked at the population of methanogens in the mire, they discovered that this newly discovered one made up 90% of the total population. As long as the soil remains frozen, these methanogens living in the frozen soil outputed small amounts of methane which is consumed by methane-eating neighbours.  The methane effectively stayed below the ice in frozen conditions. The entire picture changes, however, when the permafrost warms. With melting permafrost, the hydrogenotrophic methanogens now have access to a ready supply of their favorite nutrients – carbon dioxide and hydrogen which results in a rapid growth spurt, much like an algae bloom. The rapid growth is accompanied by large production of methane, which can contribute significantly to global warming.

Discovery of a novel methanogen prevalent in thawing permafrost ncomms4212-f1

 

Figure 40: Relative  methanogenic permafrost population of  Candidatus Methanoflorens stordalenmirensis in frozen, thawing and thawed permafrost recorded over a two year period (Source: Nature)

March, 2014 – Growing season carbon capture does not offset permafrost emissions 

The only way we can accurately project future climate is to understand the responses of both plants and microbes to a warming climate. This study was the first to simulate whole ecosystem warming in the arctic, including permafrost degradation, similar to what is projected to happen as a result of climate change. There is a strong potential for significant global carbon emissions if rates calculated here become typical for permafrost ecosystems in a warmer world.

- Sue Natali, Wood Hole Research Center

By the end of the 21st century, scientists believe that warming temperatures in the Arctic will result in a 30–70% decline in surface permafrost extent. Since permafrost contains three to seven times the amount of carbon sequestered in tropical forests, this fact has scientists worried. Until now, the IPCC reports have not included the potentially large positive feedback effects of  methane liberated by thawing Arctic permafrost C pools due to lack of hard data.  In a major step in characterizing the size of potential CO2 released by thawing permafrost, Assistance Scientist Sue Natali of the Woods Hole Research Center (WHRC) and colleagues conducted a study to characterize the net emission effects of a warming permafrost. Permafrost degradation stimulates carbon loss from experimentally warmed tundra, published in the journal Ecology distills the results of a three year study that provides initial estimates of the potential net CO2 eq. emissions that may be released due to permafrost thawing.

As the tundra warms, two competing factors come into play:

  1. longer growing season and increased plant growth captures atmospheric carbon – acting as a carbon sink
  2. thawing permafrost releases carbon into the atmosphere – acting as a carbon source

Dr. Natali said, “the understanding of permafrost feedbacks to climate change had been limited by a lack of data examining warming effects on both vegetation and permafrost carbon simultaneously”.  This is the first study that quantifies the net effect of thawing permafrosting – as either a net carbon sink or net carbon source.

Dr. Natali and her team found that growing season gains do not offset carbon emissions from permafrost thaw. This is not surprising as Dr. Natali explains “There is 100 times more carbon stored below ground than aboveground in the arctic, so observed changes in plant productivity are only a very small component of the story. Given the amount of carbon stored belowground in the arctic, it is very unlikely that plant growth can ever fully offset C losses from permafrost thaw.”

Abstract:

large pool of organic carbon (C) has been accumulating in the Arctic for thousands of years because cold and waterlogged conditions have protected soil organic material from microbial decomposition. As the climate warms this vast and frozen C pool is at risk of being thawed, decomposed, and released to the atmosphere as greenhouse gasses. At the same time, some C losses may be offset by warming-mediated increases in plant productivity. Plant and microbial responses to warming ultimately determine net C exchange from ecosystems, but the timing and magnitude of these responses remain uncertain. Here we show that experimental warming and permafrost (ground that remains below 0°C for two or more consecutive years) degradation led to a two-fold increase in net ecosystem C uptake during the growing season. However, warming also enhanced winter respiration, which entirely offset growing-season C gains. Winter C losses may be even higher in response to actual climate warming than to our experimental manipulations, and, in that scenario, could be expected to more than double overall net C losses from tundra to the atmosphere. Our results highlight the importance of winter processes in determining whether tundra acts as a C source or sink, and demonstrate the potential magnitude of C release from the permafrost zone that might be expected in a warmer climate.

 

Dr. Natali said “Our results show that while permafrost degradation increased carbon uptake during the growing season, in line with decadal trends of ‘greening’ tundra, warming and permafrost thaw also enhanced winter respiration, which doubled annual carbon losses.”

The project, named the Carbon in Permafrost Experimental Heating Research (CiPEHR) project simulated Arctic warming by warming air and soil and thawing permafrost using two warming experiments:

  1. winter warming – snow packs functioned like down comforters insulating the ground during the winter until the snow was removed at the start of the growing season.
  2. summer warming – open-topped greenhouses that warmed the air during the summer.

Warming effects on CO2 uptake by plants and release by plants and microbes were both measured.

Dr. Natali’s conclusion are in agreement with prior expectations, that “The only way we can accurately project future climate is to understand the responses of both plants and microbes to a warming climate. This study was the first to simulate whole ecosystem warming in the arctic, including permafrost degradation, similar to what is projected to happen as a result of climate change. There is a strong potential for significant global carbon emissions if rates calculated here become typical for permafrost ecosystems in a warmer world.”
permafrost-design-stimulates-carbon-loss-from-experimentally-warmed-tundra-f1

permafrost-design-stimulates-carbon-loss-from-experimentally-warmed-tundra-f2

March 5, 2014 – West Antarctic Ice Sheets is Out of Balance and in Permanent Retreat

pine island glacier nasa  
west antarctica glaciers measured from satellite observations since 2013

Figure 41: a) Satellite image of Pine Island Glacier shows an 18-mile-long crack across the glacier b) and c) West Antarctica’s glaciers measured from satellite observations since 1973. (Source: Jeremie Mouginot et al./GRL)

A March 5, 2014 study Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013

found a sustained increase in ice discharge from six large glaciers:

  1. Pine Island,
  2. Thwaites,
  3. Haynes,
  4. Smith,
  5. Pope and
  6. Kohler

into the vast common bay known as the Amundsen Sea Embayment in West Antarctica. The paper is authored by principal researchers at the Rignot Research Group at the Department of Earth System Science at University of California, Irvine and published in the March 2014 edition of the journal Geophysical Research Letters. The researchers used satellite data to look at sequential images of the glaciers from 1973 to 2013 and calculated how fast the ice was moving by tracking surface features, such as cracks in the ice, to determine the distance the glaciers over the time periods investigated.  The study shows that glaciers hundreds of kilometers inland respond to glacial disturbances at the ocean.

The study found that between 1973 to 2013 the amount of ice draining from the six glaciers increased by 77 percent. However, the race to the sea is happening at different rates:

  1. The previously fast-flowing Pine Island Glacier stabilized, slowing down starting in 2009. (The slowdown was only at the ice shelf, where the glacier meets the sea. Further inland, the glacier is still accelerating.)
  2. The researchers discovered that the Thwaites Glacier starting in 2006, has accelerated its flow. For the first time since measurements began in 1973, Thwaites starting accelerating. Thwaites quickened its pace by 0.5 miles (0.8 kilometers) per year between 2006 and 2013.

Ice from the six glaciers accounts for almost 10 percent of the world’s sea-level rise per year and is comparable to the amount of ice draining from the entire Greenland Ice Sheet annually. The researchers worry the “collapse” of West Antarctica’s glaciers would hasten sea-level rise.

Study co-author Jeremie Mouginot said warmer ocean waters contributed to the speed up. The huge ice streams flowing from West Antarctica are held back by floating ice shelves that act like dams. Several recent studies have suggested that warmer ocean water near Antarctica is melting and thinning these floating ice shelves from below. The thinner ice shelves offer less resistance, making it easier for glaciers to bulldoze their way toward the sea.”This region is considered the potential leak point for Antarctica because of the low seabed. The only thing holding it in is the ice shelf,” said Robert Thomas, a glaciologist at the NASA Wallops Flight Facility, in Wallops Island, Va., who was not involved in the study. If the ice sheets collapse, this becomes an unstoppable, self-sustaining retreat that would drop millions of tons of ice into the sea. Professor Eric Ringot, of the Ringot Research Group warns that if these glaciers melt completely, they alone would account for 1.2 meter rise in global sea level.

The research findings may lead to adjustments to existing glacier acceleration models because most current ones only take into account isolated speed changes resulting from a local disturbance and do not account for how such changes affect the glacier as a whole.


April 2014 – Arctic Sea Ice Melt Season Lengthening due to Warmer Arctic Ocean

The length of the melt season for Arctic sea ice is growing by several days each decade, and an earlier start to the melt season is allowing the Arctic Ocean to absorb enough additional solar radiation in some places to melt as much as four feet of the Arctic ice cap’s thickness, according to a new study by National Snow and Ice Data Center (NSIDC) and NASA researchers.

“The Arctic is warming and this is causing the melt season to last longer,” said Julienne Stroeve, a senior scientist at NSIDC, Boulder and lead author of the new study, which has been accepted for publication in Geophysical Research Letters. “The lengthening of the melt season is allowing for more of the sun’s energy to get stored in the ocean and increase ice melt during the summer, overall weakening the sea ice cover.”


The researchers calculated the increase in solar radiation absorbed by the ice and ocean for the period ranging from 2007 to 2011, which in some areas of the Arctic Ocean exceed 300 to 400 megajoules per square meter, or the amount of energy needed to thin the ice by an additional 3.1 to 4.2 feet (97 to 130 centimeters).

The increases in surface ocean temperatures, combined with a warming Arctic atmosphere due to climate change, explain the delayed freeze up in the fall.

“If air and ocean temperatures are similar, the ocean is not going to lose heat to the atmosphere as fast as it would when the differences are greater,” said Linette Boisvert, co-author of the paper and a cryospheric scientist at Goddard. “In the last years, the upper ocean heat content is much higher than it used to be, so it’s going to take a longer time to cool off and for freeze up to begin.”

(Source: NASA)

April 7, 2014 – Changes in peat chemistry associated with permafrost thaw increase GHG production

A team of researchers led by Florida State University Doctoral student Suzanne Hodgkins has determined that as permafrost melts, the organic matter decay increases the ratio of methane to CO2. Methane is a compound 26x more potent than CO2. The paper Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production says that the effects of this increase in organic matter reactivity with permafrost thaw could intensify the increases in CH4 and CO2 release. The team performed experiments on peat at the Stordalen mire in Sweden, which has melted quickly over the past three decades.

Abstract:

Carbon release due to permafrost thaw represents a potentially major positive climate change feedback. The magnitude of carbon loss and the proportion lost as methane (CH4) vs. carbon dioxide (CO2) depend on factors including temperature, mobilization of previously frozen carbon, hydrology, and changes in organic matter chemistry associated with environmental responses to thaw. While the first three of these effects are relatively well understood, the effect of organic matter chemistry remains largely unstudied. To address this gap, we examined the biogeochemistry of peat and dissolved organic matter (DOM) along a ∼40-y permafrost thaw progression from recently- to fully thawed sites in Stordalen Mire (68.35°N, 19.05°E), a thawing peat plateau in northern Sweden. Thaw-induced subsidence and the resulting inundation along this progression led to succession in vegetation types accompanied by an evolution in organic matter chemistry. Peat C/N ratios decreased whereas humification rates increased, and DOM shifted toward lower molecular weight compounds with lower aromaticity, lower organic oxygen content, and more abundant microbially produced compounds. Corresponding changes in decomposition along this gradient included increasing CH4 and CO2 production potentials, higher relative CH4/CO2 ratios, and a shift in CH4 production pathway from CO2 reduction to acetate cleavage. These results imply that subsidence and thermokarst-associated increases in organic matter lability cause shifts in biogeochemical processes toward faster decomposition with an increasing proportion of carbon released as CH4. This impact of permafrost thaw on organic matter chemistry could intensify the predicted climate feedbacks of increasing temperatures, permafrost carbon mobilization, and hydrologic changes.

May 13, 2014 – NASA: Collapse of West Antarctic Ice Sheets Unstoppable

Abstract

We measure the grounding line retreat of glaciers draining the Amundsen Sea Embayment of West Antarctica using Earth Remote Sensing (ERS-1/2) satellite radar interferometry from 1992 to 2011. Pine Island Glacier retreated 31 km at its center, with most retreat in 2005–2009 when the glacier un-grounded from its ice plain. Thwaites Glacier retreated 14 km along its fast-flow core and 1 to 9 km along the sides. Haynes Glacier retreated 10 km along its flanks. Smith/Kohler glaciers retreated the most, 35 km along its ice plain, and its ice shelf pinning points are vanishing. These rapid retreats proceed along regions of retrograde bed elevation mapped at a high spatial resolution using a mass conservation technique (MC) that removes residual ambiguities from prior mappings. Upstream of the 2011 grounding line positions, we find no major bed obstacle that would prevent the glaciers from further retreat and draw down the entire basin.

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Figure 42: Glaciers flowing into Amundsen Sea Embayment (Source: NASA/Eric Rignot)

Dr. Eric Rignot, principal scientist for the Radar Science and Engineering Section, professor of Earth System Science School of Physical Sciences at University of California, Irvine campus and leader of the Rignot Research Group is the lead author of a paper published in the May 2014 issue of  Geophysical Research Letter entitled Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011 which concludes that a glacial melting tipping point has been reached which will see the giant West Antarctica Glaciers flow unstoppably for centuries into the Amundsen, raising sea levels by an estimated 1.2 meters.

Three major lines of evidence support the theory of unstoppable flow into the Amundsen Sea:

  1. the changes in their flow speeds,
  2. how much of each glacier floats on seawater,
  3. the slope of the terrain they are flowing over and its depth below sea level

In an earlier 2014 paper, Rignot’s research group discussed the steadily increasing flow speeds of these glaciers over the past 40 years. This May 2014 study examines the other two lines of evidence.

Floating Glaciers

These glaciers flow out from land and must cross the land / ocean boundary at some point. The leading edges of the glacier float on the seawater. The point at which a glacier first loses contact with land is called the grounding line and nearly all glacier melt occurs on the underside of the glacier beyond the grounding line, on the section floating on warm sea water.

The NASA press release explains that “just as a grounded boat can float again on shallow water if it is made lighter, a glacier can float over an area where it used to be grounded if it becomes lighter, which it does by melting or by the thinning effects of the glacier stretching out.” The leading edge of these West Antarctic glaciers have thinned because of the glacier underside melting and are now floating above places where they used to sit solidly on land. This means their grounding lines are retreating inland.

“The grounding line is buried under a thousand or more meters of ice, so it is incredibly challenging for a human observer on the ice sheet surface to figure out exactly where the transition is,” Rignot said. “This analysis is best done using satellite techniques.”

Rignot’s team used radar data captured between 1992 and 2011 by the European Earth Remote Sensing (ERS-1 and -2) satellites to provide a picture of the retreating grounding line. The data is very precise technique, acquired using radar interferometry which can sense changes in the earths motion to a resolution of 1/4 of an inch. Rignot’s team could distinguish between data that represented horizontal and vertical movement. Glaciers move horizontally as they flow downstream, but leading edge have an additional vertical movement due to the fact that they sit atop the ocean and are moved by the rise and fall of tidal motion. Rignot’s group could find the grounding line point by examining where the vertical motion component was missing.
The accelerating flow speeds and retreating grounding lines reinforce each other in a positive feedback loop:

  1. As glaciers flow faster, they stretch out and thin,
  2. the thinning reduces their weight, lifting them farther off the bedrock,
  3. the grounding line retreats and more of the glacier becomes waterborne,
  4. This reduces the normal resistance underneath causing the flow to accelerates

Pinning Points

Slowing or stopping these changes can only occur if there is a land obstacle of sufficient size to resist the horizontal ice flow. These points of resistance are called pinning points and are typically geological features in the underlying landscape such as hills or mountains. Rignot’s team produced an accurate map of the bed elevation by combining ice velocity data from ERS-1 and -2 with ice thickness data from NASA’s Operation IceBridge mission and other airborne campaigns.

The resulting bed elevation map revealed that there were no pinning points upstream of the present grounding lines in five of the six glaciers. Only the Haynes Glacier had major bedrock obstructions upstream, but it drains a smaller sector than the other five glaciers and is retreating as rapidly as the other glaciers.

The maps Rignot’s team created also reveal that the bedrock topography slope deeper below sea level as they extend farther inland. Therefore, as the grounding point retreats further inland, the glaciers underside is exposed to even greater amounts of warm ocean water as the ocean pours into these pockets and fill what was once solid glacier with warm ocean water, accleerating glacier melt even more.

“The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating sections of the glaciers. At this point, the end of this sector appears to be inevitable,” Rignot said. Rignot warned that the accelerating flow rates combined with the lack of pinning points and sloping bedrock all lead to one compelling conclusion: The collapse of this sector of West Antarctica appears to be unstoppable. Rignot conservatively estimates it will raise global sea level by 1.2 meters.

This study was released after the IPCC’s fifth assessment report released just a few months earlier. The IPCC fifth assessment does not include sea level rise due to melting ice sheets from the West Antarctic region because research data had not been available yet at the time of publication. The IPCC fifth assessment predicts global sea level rise between 0.3 and 1 meter by end of century. Scientists such as professor Sridhar Anandakrishnan, a Geosciences researcher at Pennsylvania State University have said that this means it will certainly be closer to the 1 meter mark. Anandakrishnan also said that a significant loss of the ice sheets that flow into the Amundsen Sea Embayment may destabilize other surrounding ice sheets in a domino effect and NASA states that the entire West Antarctic ice sheet, if melted could raise sea level by almost 5 meters.

July 3, 2014 – Forest Fires burning out of control in North West Territories

NWT fire map aug 1 2014

Figure 43: August 1, 2014 Fire map of North West Territory in Canada  (Source: NWT Fire)

arctic-news-smoke-blankets-NA 
darksnow_July3_2014_fires 

Figure 44:  a) Map of fire smoke and soot pattern (Source: Arctic News Blog)     b) NASA thermal imagery map fires in NWT (Source: Darksnow project)

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   NWT fire  
NWT fire2
Figure 45:  a) Birch Creek Fire complex (Source: Climate Central)  b) Fire in NWT (Source: Laura MacNeill) c) NWT fires from space (Source: Huffington Post Canada)

July 24, 2014 – Large Amounts of Methane Outgassing detected in Arctic by Sewrus-C3 Expedition

Even if a small fraction of the Arctic carbon were released to the atmosphere, we’re fucked,…the methane bubbles were reaching the surface. That was something new in my survey of methane bubbles


Just a week into the sampling program in the Arctic Ocean, the SWERUS-C3 team of scientists have discovered vast methane plumes escaping from the seafloor of the Laptev continental slope.Expedition leader Örjan Gustafsson writes this on his blog:

So, what have we found in the first couple of days of methane-focused studies?

  1. Our first observations of elevated methane levels, about ten times higher than in background seawater, were documented already as we climbed up the steep continental slope at stations in 500 and 250 m depth. This was somewhat of a surprise. While there has been much speculation of the vulnerability of regular marine hydrates (frozen methane formed due to high p and low T) along the Arctic rim, very few actual observations of methane releases due to collapsing Arctic upper slope marine hydrates have been made. ¨
  2. It has recently been documented that a tongue of relatively varm Atlantic water, with a core at depths of 200–600 m may have warmed up some in recent years. As this Atlantic water, the last remnants of the Gulf Stream, propagates eastward along the upper slope of the East Siberian margin, our SWERUS-C3 program is hypothesizing that this heating may lead to destabilization of upper portion of the slope methane hydrates. This may be what we now for the first time are observing.
  3. Using the mid-water sonar, we mapped out an area of several kilometers where bubbles were filling the water column from depths of 200 to 500 m. During the preceding 48 h we have performed station work in two areas on the shallow shelf with depths of 60-70m where we discovered over 100 new methane seep sites. SWERUS-C3 researchers have on earlier expeditions documented extensive venting of methane from the subsea system to the atmosphere over the East Siberian Arctic Shelf. On this Oden expedition we have gathered a strong team to assess these methane releases in greater detail than ever before to substantially improve our collective understanding of the methane sources and the functioning of the system. This is information that is crucial if we are to be able to provide scientific estimations of how these methane releases may develop in the future.

Sept 16, 2014 – Greenland is now “Blackland” due to Forest Fire Soot

Research Jason Box has been working on a crowdfunded research project called the Dark Snow Project and shares his dramatic pictures of the darkening impacts of forest fire and man-made pollution soot and aerosols on Arctic glaciers. The slideshow below is based on pictures of Greenland on a recent expedition and originally published in a story in Slate magazine. The amount of additional melting from the change in Albedo is significant and Box compares it to twice the amount of energy used to generate electricity every year contributing to the melting on Greenland.

 

Some Cryosphere Scientists

Some of the leading authorities studying the Arctic Methane and Methane Hydrate Time Bomb are:

Geologic methane seeps along boundaries of Arctic permafrost thaw and melting glaciers by: Katey M. Walter AnthonyPeter AnthonyGuido Grosse Jeffrey Chanton
Abstract: Methane, a potent greenhouse gas, accumulates in subsurface hydrocarbon reservoirs, such as coal beds and natural gas deposits. In the Arctic, permafrost and glaciers form a ‘cryosphere cap’ that traps gas leaking from these reservoirs, restricting flow to the atmosphere. With a carbon store of over 1,200 Pg, the Arctic geologic methane reservoir is large when compared with the global atmospheric methane pool of around 5 Pg. As such, the Earth’s climate is sensitive to the escape of even a small fraction of this methane. Here, we document the release of 14C-depleted methane to the atmosphere from abundant gas seeps concentrated along boundaries of permafrost thaw and receding glaciers in Alaska and Greenland, using aerial and ground surface survey data and in situ measurements of methane isotopes and flux. We mapped over 150,000 seeps, which we identified as bubble-induced open holes in lake ice. These seeps were characterized by anomalously high methane fluxes, and in Alaska by ancient radiocarbon ages and stable isotope values that matched those of coal bed and thermogenic methane accumulations. Younger seeps in Greenland were associated with zones of ice-sheet retreat since the Little Ice Age. Our findings imply that in a warming climate, disintegration of permafrost, glaciers and parts of the polar ice sheets could facilitate the transient expulsion of 14C-depleted methane trapped by the cryosphere cap.
“Clearly, our findings over the last five years that have had the greatest impact on scientific conversations have had to do with methane release in the Arctic—especially around the East Siberian Arctic Shelf, off the northern coast of Siberia. The reason these observations have received so much attention is that methane is a very potent greenhouse gas—roughly 25 times more potent than carbon dioxide. Also, the methane release that we have identified in the Arctic is both unprecedented in terms of its volume and has the potential to increase greatly if warming trends continue. The Arctic land and coastal seabed is unique because much of it is permafrost, which means that it can thaw if properly warmed, releasing the gases that until now have been trapped inside. These gases include carbon dioxide and methane, among others. And when methane gas emissions bubble up from the sea, rather than the more common diffusion (gradual release through soil), the emissions are more potent, since there is not enough time for microbes to convert the gas into carbon dioxide.” – Dr. Igor Semiletov
” A large (multi-gigaton) abrupt release event is considered possible, but when is not known. It is important to remember that hydrocarbons, including methane, migrate upwards through the Earth’s crust from their source-rocks due to their low density. Basic oil geology tells us that recoverable oil and gas deposits occur where such upward migration has been blocked by an impermeable barrier (an oil- or gas-trap) such as a salt-dome or anticline including thick impermeable strata such as a clay-bed. In such places, the accumulation can build up to the point where the oil/gas is in an highly pressurised state – hence the “blowouts” that have been recorded over the years in some oilfields.” –Dr. Natalia Shakhova
 
Kevin Shaefer, research scientist at the National Snow and Ice Data Center in Boulder is the lead author of the paper Amount and timing of permafrost carbon release in response to climate warming published in Feb 2010 in the Swedish meteorological journal Tellus. The paper concludes that between 1/3 and 2/3 of Earth’s permafrost will disappear by 2200, unleashing vast quantities of carbon into the atmosphere. “The amount of carbon released is equivalent to half the amount of carbon that has been released into the atmosphere since the dawn of the industrial age,” said NSIDC scientist Kevin Schaefer. “That is a lot of carbon.” 
The paper concludes that the Arctic will evolve from a carbon sink to a carbon source as permafrost melting is unavoidable. His team’s conservative estimates project that by 2020, the amount of carbon emitted will offset anywhere from 42 to 88 percent of the Arctic’s current carbon sinking effect. The Permafrost Carbon Feedback cycle will certainly mean that fossil fuel emissions will need to be reduced even further to prevent runaway greenhouse effects
 
Matt Hornbach is a geophysicist with SMU’s Huffington Department of Earth Science and the lead author of the paper Recent changes to the Gulf Stream causing widespread gas hydrate destabilization published in the Oct 24, 2012 edition of Nature.  ” The paper concludes that recent changes in in intermediate-depth ocean temperature associated with the Gulf Stream ocean current flowing from the Gulf of Mexico and northward to the North Atlantic and Arctic is rapidly destabilizing methane hydrate along a broad swathe of the North American margin. 
The analysis suggests that changes in Gulf Stream flow or temperature within the past 5,000 years or so are warming the western North Atlantic margin by up to eight degrees Celsius and are now triggering the destabilization of 2.5 gigatonnes of methane hydrate (about 0.2 per cent of that required to cause the PETM). This destabilization extends along hundreds of kilometres of the margin and may continue for centuries. It is unlikely that the western North Atlantic margin is the only area experiencing changing ocean currents
References 1. Dmitrenko, I.A., Kirillov, S.A., Tremblay, L.B., Kassens, H., Anisimov, O.A., Lavrov, S.A., Razumov, S.O. & Grigoriev, M.N. (2011): Recent changes in shelf hydrography in the Siberian Arctic: Potential for subsea permafrost instability. Journal of Geophysical Research, 116, C10027. Abstract 2. Shakhova NE, Semiletov I, Salyuk A, Yusupov V, Kosmach D (2008). Anomalies of methane in the atmosphere over the East Siberian shelf.  Geophysical Research Abstracts 10, EGU2008-A-01526. Abstract General Sources: National Snow and Ice Data CenterThinkprogress,  Planetsave, The Independent, New York Times