Dramatic rise in methane levels since end July 2013

There has been a dramatic rise in methane levels since end July 2013. The image below pictures methane levels above 1950 ppb on the Northern Hemisphere from 12 p.m. August 9, 2013, to 12 a.m. August 10, 2013.

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Quite suddenly, readings above 1950 ppb have become commonplace since July 31, 2013.

The chart below illustrates the dramatic jump in methane levels that occurred since July 31, 2013. The chart shows the area (square km) with methane readings over 1950 ppb for selected layers, over the period from July 24, 2013, to August 9, 2013. The chart further below shows that peak methane levels have increased dramatically.

Particularly worrying are high levels of methane over the Arctic Ocean, such as on the image below showing methane levels over 1950 ppb in yellow for selected layers on August 5, 2013 (a.m.).

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Methane levels are also very high on the Southern Hemisphere, as illustrated by the image below on the right. High readings have featured over the heights of Antarctica for quite some time, but the high levels of methane over the oceans on the Southern Hemisphere have only shown up recently. They could be caused by one or more methane hydrates getting destabilized in the ocean between Antarctica and South America.

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Peter Carter sent the image below, edited from NOAA Earth System Research Laboratory, showing high (and rising) methane levels in Pallas Sammaltunturi (north Scandinavia), measured with surface flasks.

Peter also added the image below, pointing at high methane levels in Lac La Biche, Northern Alberta, Canada. “What to make of it?”, Peter adds, “It is not far from the Tar Sands - that does have a methane problem, but it is basically wetland peat region vicinity which is why I checked it.”

Methane levels remain very high around the globe

The image below shows methane levels over 1950 in yellow for both hemispheres, on the morning of August 8, 2013.

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The highest peak recorded was 2428 ppb at 367 mb. The highest mean was 1822 ppb at 469 mb. See also the image below for an overview of recent methane levels.

for interactive version, see http://arctic-news.blogspot.com/2013/08/methane-levels-keep-rising-rapidly.html

The situation is very worrying, especially since there's a huge amount of methane in the northern part of Asia and Europe, much of it bordering on the Arctic. This methane will trap a lot of heat there at a time when the melting season is still going strong.

On the Southern Hemisphere, there's a huge amount of methane recorded over Antarctica. That has been going on for quite some time, but the high levels of methane over the oceans on the Southern Hemisphere have only shown up recently. They could be caused by one or more methane hydrates getting destabilized in the ocean between Antarctica and South America.

Toward Genuinely Improved Discussions of Methane & Climate

The post 'Toward Improved Discussions of Methane & Climate' recently appeared at SkepticalScience, in response to the recent publication in Nature of 'Vast Costs of Arctic Change', by Gail Whiteman, Chris Hope, and Peter Wadhams.

Below are Paul Beckwith's comments that were recently submitted at that post. The text by SkepticalScience is in italics. Paul's comments are in red.

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SkepticalScience: “Here at Skeptical Science, there is an ongoing effort to combat disinformation from those who maintain that climate change is a non-issue or non-reality. From time to time, however, individuals or groups overhype the impacts of climate change beyond the realm of plausibility. Some of this is well-intentioned but misguided. For those who advocate climate literacy or for scientists who engage with the public, it is necessary to call out this stuff in the same manner as one would call out a scientist who doesn’t think that the modern CO2 rise is due to human activities.

Many overblown scenarios or catastrophes seem to involve methane in the Arctic in some way. There are even groups out there declaring a planet-wide emergency because of catastrophic, runaway feedbacks, involving the interplay between high latitude methane sources and sea ice.”

Paul Beckwith: The above two paragraphs set the tone of this discourse. AMEG (Arctic Methane Emergency Group) is unjustly framed in this introduction as a fringe group using such terms as “overhype”, “beyond realm of plausibility”, “overblown scenarios or catastrophes”, “planet-wide emergency”. This is the complete opposite of the truth. AMEG was founded based on a meeting in October, 2011 in the U.K. and I joined in December, 2011. We are a group of concerned professionals with a varied background including climate scientists, engineers, doctors, moviemakers, economists, journalists.

We have studied the Arctic, methane, sea ice, and climate change as a group since that time, and individually for much longer. We base our work and analysis on observations, not on models.

The facts on the ground and ocean in the Arctic region speak for themselves. The PIOMAS work, which has been substantiated independently by CryoSat satellite data, show that the sea ice volume is trending downwards exponentially and if that trend continued would reach zero around 2015 or 2016. Trending down even faster is the May and June Arctic snow cover, as measured clearly by Rutgers data. Methane levels in the Arctic have increased significantly over the last several years. In fact, the mainstream scientific viewpoint was that the seafloor over the ESAS (Eastern Siberia Arctic Shelf) was impermeable to methane outgassing. Then Shakhova, Yurganov, and other Russian scientists measured outgassing plumes tens of meters in diameter one year expanding to kilometers in diameter the very next year. Flask measurements in Barrow, Alaska and Svalbaard indicated local levels of >2100 ppb and AIRS satellite measurements over the last decade have shown greatly increase levels of methane in the last few years. This is all observation, and not modeled by anybody. In fact, higher methane emissions have been reported along the Arctic coastlines, presumably from enhanced wave action due to larger wave action from the increased ice-free ocean.

Also, higher emissions have been measured elsewhere from continental shelves, for example off the east coast of North America from warm Gulf Stream water that has shifted eastward over the shelves, warming ocean temperatures several degrees.

Thus, the “radical” or “fringe” or “out-there” view is not from AMEG, quite the opposite. Based on the precautionary principle, it is imperative that so called “mainstream” science examine this data without preconceptions that it takes centuries or millennia for methane to outgas. It is unfathomable to AMEG and many others that main-stream science are behaving like “methane denialists” when the observations are clearly undermining such out-of-hand rejection, based on inaccurate models that are clearly missing feedbacks. In fact the situation is so ridiculous that the IPCC is not even considering methane as a strong feedback in their next report.

People on the street are now recognizing that the weather extremes are moving off the charts in terms of frequency, severity, and spatial extent (mostly for extensive long duration droughts, and also torrential rains causing floods). They are starting to recognize that the collapse in Arctic albedo from declining snow cover and sea ice loss is greatly amplifying the warming in the Arctic. This obviously lowers the temperature gradient between the equator and North Pole which via simple physical laws slows the jet streams making them wavier and stickier. This changing global circulation, combined with 4% higher water vapor in the atmosphere is causing these weather extremes.

Things are happening that have never been observed before in human history. Like the rate of decline of sea ice and snow cover, the extensive cracking of sea ice this March-2013, the “hole” forming near the north pole from relatively weak cyclones, the massive, long duration cyclone at the beginning of August-2012, and the list goes on and on. AMEG being extreme? Hardly, more like science compartmentalization and specialization being myopic to the collection of system changes that are screaming out that the climate system has entered a period of abrupt change that has not been seen before in human history, but has happened many times in the paleorecords. In fact, rates of change now are at least 10x higher than any seen in the geologic record.

SkepticalScience: About a week ago, a Nature article by Gail Whiteman, Chris Hope, and Peter Wadhams came out analyzing the "Vast Costs of Arctic Change." The Whiteman article is an honest and thoughtful commentary about the economic impacts of a changing Arctic climate. I will not comment on their economic modeling here, but rather on a key scenario assumption that they use which calls for vast increases in Arctic-sourced methane to the atmosphere. In this case, they have in mind a very rapid pulse of 50 Gigatons of methane emanating from the East Siberian Shelf (see image, including Laptev and East Siberian sea). Note: 1 GtCH4= 1 Gigaton of methane = 1 billion tons of methane. Whiteman et al. essentially assume that this "extra methane" will be put in the atmosphere on timescales of years or a couple decades. This article has been widely publicized because it calls for an average of 60 trillion dollars on top of all other climate change costs. Since this was discussed in a prediction context rather than as a thought experiment, it demands analysis of evidence.

In this article, I will argue that there is no compelling evidence for any looming methane spike. Other scientists have spoken out against this scenario as well, and I will encompass some of their arguments into this piece. In summary, the reason a huge feedback is unlikely is because of the long timescale required for global warming to reach some of the largest methane hydrate reservoirs (defined later) (Paul Beckwith: no methane was expected from ESAS since seafloor was thought to be impermeable, until it was measured to rapidly outgas from one year to the next), and because no evidence exists for such an extreme methane concentration sensitivity to climate in the past record (Paul Beckwith: methane pulses released over several years or a few decades is not detectable in ice cores since bubble closure below firn takes about 50 years or more).Permafrost feedbacks are of concern, but there is no basis for assuming a dramatic "tipping point" in the atmospheric methane concentration (Paul Beckwith: no basis for this statement since observations show large increase in methane).

The Methane Tour

Methane (CH4) is a greenhouse gas. It absorbs thermal energy that the Earth is trying to shed into outer space, and can thus warm the surface of the planet. Its concentration in the modern atmosphere is a little bit shy of 2 parts per million by volume (ppm), compared to roughly 0.72 ppm in 1750 or 0.38 ppm in typical glacial conditions. Like CO2, methane has not risen to modern day concentrations during the entirety of the now ~800,000 year long ice core record.

So what about Whiteman's scenario?

For perspective on how big 50 GtCH4 is, I've used data from David Archer's online methane model to see how atmospheric methane concentrations would change in response to such a big carbon injection. You can do this as a back-of-envelope calculation by noting that 1 ppm is about 2.8 GtCH4 if it all stays as methane and isn't removed, but this model lets you see the decay timescale too. For methane, the decay back to original concentrations occurs within decades, whereas for CO2 it takes millennia (CH4 is rapidly oxidized by the hydroxyl radical in the atmosphere). Therefore, CO2 dominates the long-term climate change picture but the methane spike can induce very large transitory effects. (Paul Beckwith: keep in mind that the methane lifetime varies greatly depending on the availability of the hydroxyl radical. On average it is 12 years, however in dry regions like the Arctic with little water vapor it is longer, while at moist equatorial regions it is shorter).

I've run two scenarios in which the 50 GtCH4 injection takes 1 year and 10 years to complete (red and blue lines, respectively). The model starts with pre-industrial CH4 concentrations in years -10 through zero. The modern concentration of methane is shown as a horizontal orange line.



Everything having to do methane in the ice core record resides below the orange line in Figure 1 (at least within the resolution of the cores). So we're potentially talking about a very big change, which the Whiteman article contends is likely to be emitted fairly soon and should have implications for Arctic policy. (Paul Beckwith: This graph clearly demonstrates that if glacial ice bubble closure takes 50 years, then the pulse will not be captured. Also, the molecular weight of CH4 is 16 compared to 30 or so for air (mostly N2) so the methane does not stay around the surface for long).

For many, the primary concern about “big” abrupt changes in atmospheric CH4 stems from the large quantity of CH4 stored as methane hydrate or in permafrost in the Arctic region. These terms are defined below. It should be noted that globally, wetlands are the largest single methane source to the modern atmosphere. Most of that contribution is from the tropics and not from high latitudes (even if the Arctic was to start pumping harder). The Denman et al., 2007 carbon cycle chapter in the last IPCC report is a useful reference. (Paul Beckwith: methane from wetlands in tropics has short lifetime due to extremely large quantities of water and thus hydroxyl ions in that region, as opposed to methane from the Arctic in much drier conditions)

Nonetheless, the Arctic is a region that is quite dynamic and is changing rapidly. The high latitudes are currently a CO2 sink (Paul Beckwith: this cannot be correct, since CO2 concentrations are higher in the Arctic than the global values measured at Mauna Loa, for example) and CH4 source in the modern atmosphere, and it’s not implausible that the effectiveness of the sink could diminish (or reverse) or that the methane source could enhance in the future, since we expect a transition to a warmer, wetter climate with an extended thawing season. This makes the carbon budget in the Arctic a “hot” place for research.

In these discussions, it is important to clarify what sort of methane source we're talking about.

Methane hydrate is a solid substance that forms at low temperatures / high pressures in the presence of sufficient methane. It is an ice-like substance of frozen carbon, occurring in deep permafrost soils, marine continental margins, and also in deeper ocean bottom sediments. It's also very concentrated (a cubic foot of methane hydrate contains well over 100 times the same volume of methane gas).

On the decade-to-century timescale, the liberation of methane from the marine hydrate reservoir (or the deep hydrates on land) should be well insulated from anthropogenic climate change. Deep ocean responses by methane are a very slow response (many centuries to millennia, Archer et al., 2009). Methane released in deep water also needs to evacuate the water column and get to the atmosphere in order to have a climate impact, although much of it should get eaten up by micro-organisms before it gets the chance. These issues are discussed in a review paper by O’Connor et al., 2010. (Paul Beckwith: Methane response in deep ocean is not always slow, thus this section is very misleading. Underwater landslides from slope instability or earthquakes are know to have resulting in large methane pulses many times in the paleorecords. For example, Storegga off Norway or off New Zealand, there are extensive pockmarks on the ocean floor indicating abrupt episodic events. The mainstream view that methane outgassing from deep water regions does not enter the atmosphere. If release is slow that is correct, however rapid outbursts overwhelm the micro-organisms and result in large amounts of methane entering the atmosphere. Even slower releases from deep water off Svalbard have been observed recently to enter the atmosphere; another unexpected development).

There’s also carbon in near-surface permafrost, which is the more vulnerable carbon pool during this century. Permafrost is frozen soil (perennial sub-0°C ground), and can also encompass the sub-sea permafrost on the shelves of the Arctic Ocean. This includes the eastern Siberian shelf, a very shallow shelf region (only ~10-20 m deep, and very broad, extending a distance of 400– 800 km from the shoreline). This is a bit of a special case. These subsea deposits formed during glacial times, when sea levels were lower and the modern-day seafloor was instead exposed to the cold atmosphere. The ground then became submerged as sea levels rose (going into the warmer Holocene). The rising seas have been warming the deposits for thousands of years. Because of their exposure during the Last Glacial Maximum, the shelves may be almost entirely underlain by permafrost from the coastline all the way down to a water depth of tens or even a hundred meters (e.g., Rachold et al., 2007 and this USGS page).

There's actually no good evidence of shallow hydrate on the Siberian shelves, even though there are substantial quantities of subsea permafrost. Hydrate may exist deeper down however, more than 50 meters below the seafloor. The stability of these hydrates is sustained by the existence of permafrost, and it's not quite clear to what extent hydrate can also be stored within the permafrost layer. (Paul Beckwith: Permafrost people have an over-reliance on uniform slab models which examine time taken for heat to propogate through the slabs to melt the deep permafrost. They severely underestimate the fracturing and nonuniform nature of the permafrost, presence of taliks, etc. All that is needed is one weak spot or fracture region and heat can transfer downward much faster and further than the models suggest. Similar slab models are used to estimate glacial ice melting and they have clearly been incorrect and completely underestimate the rates of melting from dynamic effects and Moulin pathways, for example.)

The estimates of the amount of methane in these various Arctic reservoirs are very uncertain. Ballpark numbers are a couple thousand gigatons of carbon (GtC) stored in hydrates in global marine sediments (e.g., Archer et al., 2009) of which a couple hundred gigatons of carbon are in the Arctic Ocean basin, and between 1000-2000 GtC in permafrost soil carbon stocks (e.g., Tarnocai et al., 2009) after you include the deeper deposits. For comparison, there is a bit over 800 GtC in the atmosphere, of which about 5 Gt is in the form of methane, and estimated ~5000 GtC in the remaining fossil fuel reserve. These numbers seem big compared to the atmosphere, but for methane direct comparison isn't too relevant unless you put it in rapidly, since it has such a short lifetime in the atmosphere. Large amounts of CO2, in contrast, last much longer.

A couple years ago, Shakhova et al. (2010a) reported extensive methane venting in the eastern Siberian shelf and suggested that the subsea permafrost could become unstable in a future warmer Arctic. Shakhova et al (2010b) cite ~1400 Gt in the East Siberian Arctic Shelf, which comprises ~25% of the Arctic continental shelf and most of the subsea permafrost. Shakhova et al (2010c) ran through a few different pathways in which they argued for 50 GtCH4 release to the atmosphere either in a 1-5 year belch or over a 50-yr smooth emission growth, which they suggest, “significantly increases the probability of a climate catastrophe.” This assessment was the foundation for the concern in the recent Whiteman Nature article, linked at the top.

The physical mechanism outlined by some of these authors is related to the rapid reduction in Arctic summer sea ice observed over the last few decades, which allows for greater amounts of solar radiation to penetrate the waters around the Arctic shelf. Warming water propagates down in the well-mixed layers tens of meters to the seabed, and might melt frozen sediments underneath. Because the shelf in this region is shallow (compared to other regions), one doesn't need to wait a long time for the seafloor to feel the atmosphere-surface forcing, and methane leakage might have an easier escape path to the atmosphere. Allegedly, this has been leading to an acceleration of methane flux.

Responses from Scientists

As a response to the first paper from Shakhova on enhanced methane fluxes, Petrenko et al (2010) criticized the authors for misunderstanding several of their references and primarily for the logical implications of their conclusions. For example,

“A newly discovered CH4 source is not necessarily a changing source, much less a source that is changing in response to Arctic warming. Shakhova et al. do acknowledge these distinctions, but in these times of enhanced scrutiny of climate change science, it is important to communicate all evidence to the scientific community and the public clearly and accurately”

(Paul Beckwith: Examination of the methane concentrations in the atmosphere in the Arctic region from AIRS satellite data over a decade or so shows an obvious large increase in the amount of methane, and has been corroborated with flask measurements at locations across the Arctic, namely Barrow, Alaska and Svalbard. How is this not a changing source?)

Another paper, Dmitrenko et al (2011) reinforced this statement and came to the conclusion that there is currently no evidence that Arctic shelf hydrate emissions have increased due to global warming. This is also discussed in the review article by O'Connor et al (2010, linked above). (Paul Beckwith: Again, does one trust a direct observation or a conclusion from a paper? Obviously the direct observation.)

The work done by the Dmitrenko paper shows that although the changing Arctic atmosphere has led to warmer temperatures throughout the water column (over the eastern Siberian shelf coastal zone), it takes a very long time for the permafrost feedback at the bed to respond to this signal. They noted that the deepening of the permafrost table should only have been on the order of 1 meter over the last several decades, which does not permit a rapid destabilization of methane hydrate.  (Paul Beckwith: Deepening of the permafrost table of 1 meter over several decades is based on a slab model and let to the erroneous mainstream view that the seafloor over the ESAS was impermeable to methane release. Measurements show otherwise.)

It is important to emphasize that simple point source emission estimates are not often suitable for determining changed sources and sinks over the last few decades, and thus don't tell you how that translates into atmospheric concentration. This should be kept in mind when seeing dramatic videos of methane venting from a shelf or exploding lake, which might not actually have much to do with global warming. (Paul Beckwith: This is a very alarming view, and would fit in fine on any of numerous climate denial websites. Rapid methane emissions in the Arctic are what they are. Call a spade a spade.)

In 2008, there was a comprehensive report on Abrupt Climate Change from the U.S. Climate Change Science Program, which is a bit dated but nonetheless makes a statement reflecting most of current scientific thinking. Quoting Ch. 5 Brook et al (2008):

"Destabilization of hydrates in permafrost by global warming is unlikely over the next few centuries (Harvey and Huang, 1995). No mechanisms have been proposed for the abrupt release of significant quantities of methane from terrestrial hydrates (Archer, 2007). Slow and perhaps sustained release from permafrost regions may occur over decades to centuries from mining extraction of methane from terrestrial hydrates in the Arctic (Boswell, 2007), over decades to centuries from continued erosion of coastal permafrost in Eurasia (Shakova [sic] et al., 2005), and over centuries to millennia from the propagation of any warming 100 to 1,000 meters down into permafrost hydrates (Harvey and Huang, 1995)" (Paul Beckwith: Again, slab model thinking. Episodic events like landslides negate these claims, as does fractures and other weakspots in the slabs which allow pathways for huge heatflow. A good analogy is polyanas in sea ice that allow for enormous heat flow between the ocean and the atmosphere in a sea ice field.)

Paleo-Analogs

One of the primary reasons we don't think there's as much methane sensitivity to warming as has been proposed by Shakhova, and argued for in the Whiteman Nature article, is because there's no evidence for it in the paleoclimate record.  This has been a point made by Gavin Schmidt on Twitter (a compilation of his many tweets on the topic here) but the objections to the Nature assumptions have been further echoed in recent days by other scientists working on the Arctic methane issue (e.g., here, here).

One can argue from a process-based and observations-based approach that we don't understand everything about Arctic methane feedback dynamics, which is fair. Nonetheless, the methane changes on the scale being argued by Whiteman et al. should have been seen in the early Holocene (when Summer Northern Hemispheric solar radiation was about 40 W/m2 higher than today at 60 degrees North, 7000-9000 years ago). (Paul Beckwith: Earth tilt was larger, so Winter Northern Hemispheric solar radiation was about 40 W/m2 lower than today at 60 degrees North. Thus, the ice formed much more quickly and much thicker in the winter back then. Also, at night much more heat was radiated out to space in the lower GHG world then as compared to our 400 ppm levels today). Even larger anomalies occurred during the Last Interglacial period between 130,000 to 120,000 years ago, though with complicated regional evolution (Bakker et al., 2013). 

Both of these times were marked by warmer Arctic regions in summer without a methane spike. It's also known pretty well (see here) that summertime Arctic sea ice was probably reduced in extent or seasonally free compared to the modern during the early Holocene, offering a suitable test case for the hypothesis of rapid, looming methane release. (Paul Beckwith: Incorrect, the summertime Arctic is not believed to be seasonally ice free during these periods. The last time this happened was likely 2 or 3 million years ago.)

It should be noted that Peter Wadhams did offer a response recently to the criticisms of the Whitehead Nature piece (Wadham is a co-author) but did not address why this idea has not been borne out paleoclimatically.

Yesterday, an objection to the paleoclimate comparison cropped up in the Guardian suggesting that the early Holocene or Last Interglacial analogs are not suitable pieces of evidence against rapid methane release. They aren't perfect analogs, but the argument does not seem compelling. (Paul Beckwith: Colder winters in the early Holocene and Last Interglacial and much colder nights (in summers and winters then) meant much thicker and extensive ice formation in winters, and slower melting at night, respectively. Compelling arguments.) The Northeast Siberian shelf regions have been exposed many times to the atmosphere during the Pleistocene when sea levels were lower (and not covered by an ice sheet since at least the Late Saalian, before 130,000 years ago, e.g., here). As mentioned before, when areas such as the Laptev shelf and adjacent lowlands were exposed, ice-rich permafrost sediments were deposited. The deposits become degraded after they are submerged (when sea levels increase again), resulting in local flooding and seabed temperature changes an order of magnitude greater than what is currently happening. Moreover, the permafrost responses have a lag time and are still responding to early Holocene forcing (some overviews in e.g., Romanovskii and Hubberten, 2001; Romanovskii et al., 2004; Nicolsky et al., 2012). A book chapter by Overduin et al., 2007 overviews the history of this region since the Last Glacial Maximum. These texts also suggest that large amounts of submarine permafrost may have existed going back at least 400,000 years. It therefore does not seem likely that the seafloor deposits will be exposed to anything in the coming decades that they haven't seen before. (Paul Beckwith: What is unique now is the extremely high concentration levels of CO2 (400ppm) and CH4 (>1900ppb). These high concentrations trap the heat in the troposphere 24/7. Thus, at night heat loss is limited by the GHG blanket. At all previous times the GHG blanket was much weaker, with CO2 ranging from 180 to 280 ppm and CH4 ranging from 350 to 700 ppb, or so. This makes an enormous difference.)

What about other times in the past? Fairly fast methane changes did occur during the abrupt climate change events embedded within the last deglaciation (e.g., Younger Dryas), just before the Holocene when the climate was still fluctuating around a state colder than today. These CH4 changes were slower than the abrupt climate changes themselves, and have been largely attributed to tropical and boreal wetland responses rather than high latitude hydrate anomalies. Marine hydrate destabilization as a major driver of glacial-interglacial CH4 variations has also been ruled out through the inter-hemispheric gradient in methane and hydrogen isotopes (e.g., Sowers, 2006) (Paul Beckwith: Episodic events like landslides, as mentioned before, cannot be discounted. In fact geological events like landslides occur at much higher frequencies when there is a rapid temperature transition, as covered extensively in Bill McGuire’s new textbook. Also, the text on “The Clathrate Gun hypothesis” cannot be completely discounted.)

To be fair, we don't have good atmospheric methane estimates during warmer climates that prevailed beyond the ice core record, going back tens of millions of years. Methane is brought up a lot in the context of the Paleocene-Eocene Thermal Maximum (PETM, 55 million years ago). During this time, proxy records show global warming at the PETM (similar to what modern models would give for a quadrupling of CO2), extending to the deep ocean and lasting for thousands of years. In addition, there were substantial amounts of carbon released. It may very well be that isotopically light carbon came from a release of some 3,000 GtC of land-based organic carbon, rather than a destabilization of methane hydrates, although this is a topic of debate and ongoing research (see e.g., Zeebe et al., 2009; Dickens et al., 2011).

It's also important to emphasize that any destabilization of oceanic methane hydrates at the PETM, or any other time period, would imply that the carbon release is a feedback to some ocean warming that occurred first- perhaps on the order of 1000 years beforehand. Furthermore, once methane was in the atmosphere, it would oxidize to CO2 on timescales significantly shorter than the PETM itself (decades.) Unfortunately, there is no bullet-proof answer right now for what caused the PETM, but rather several hypotheses that are consistent with proxy interpretation. However, methane cannot be the only story.

The Role of Methane in Climate (Change)

To be clear, CH4 is important as we go forward, and is already a key climate forcing agent behind CO2 (coming in at ~0.5 W/m2 radiative forcing since pre-industrial times). Additionally, methane is quite reactive in the atmosphere, and the effect of other things like tropospheric ozone, aerosols, or stratospheric water vapor are partly slaved to whatever is happening to methane (Shindell et al., 2009). This means methane emitted has a bigger collective impact on climate than if you just do the radiative forcing calculation by comparing methane concentration changes to what it was in 1750. (Paul Beckwith: It is important to point out an enormous misconception in public and scientific reports on methane regarding the Global Warming Potential (GWP). A number in the low 20s is almost always reported (22x, 25x…) and is based on a 100 year timescale. On a 20 year timescale, methane GWP is around 70x, and on a 1 or 2 year timescale the GWP is >150x. Clearly, in terms of methane in the Arctic sourced from marine or terrestrial permafrost the number of significance to sea ice and localized warming is 150x.)

Permafrost thawing is also going to be important in the coming century (this is a good paper), and the uncertainties pretty much go one way on this. There's not much wiggle room to argue that permafrost will reduce CH4/CO2 concentrations in the future. This is also likely to be a sustained release rather than one big catastrophic event. For example, permafrost was not included in Lenton (2008) as a "tipping point" for precisely the reason that there's no evidence for any "switch" of rapid behavior change. (Paul Beckwith: Exclusion of methane as a “tipping element” in this paper by the “experts” in 2008 was based on rates of change based on slab models, which recent observations of emissions has clearly invalidated). Much of the carbon is also likely to be in the form of CO2 to the atmosphere, and even implausible thought experiments of catastrophic methane release (see David Archer's post at RealClimate) give you comparable results in the short-term as to what CO2 is going to do for a long time.

Conclusion

The observed methane venting from the East Siberian shelf sea-floor to the atmosphere is probably not a new component of the Arctic methane budget. Furthermore, warming of the Arctic waters and sea ice decline will likely impact subsea permafrost on longer timescales, rather than the short term. (Paul Beckwith: Is this author so sure of this as to be willing to stake the stability/instability of the entire global circulation system on this?)

Methane feedbacks in the Arctic are going to be important for future climate change, just like the direct emissions from humans. This includes substantial regions of shallow permafrost in the Arctic, which is already going appreciable change. Much larger changes involving hydrate may be important longer-term. Nonetheless, these feedbacks need to be kept in context and should be thought of as one of the many other carbon cycle feedbacks, and dynamic responses, that supplement the increasing anthropogenic CO2 burden to the atmosphere. There is no evidence that methane will run out of control and initiate any sudden, catastrophic effects. (Paul Beckwith: There is no evidence that methane will not run out of control, in light of large increases of concentrations in recent years).  There's certainly no runaway greenhouse. Instead, chronic methane releases will supplement the primary role of CO2. Eventually some of this methane oxidizes into CO2, so if the injection is large enough, it can add extra CO2 forcing onto the very long term evolution of global climate, over hundreds to thousands of years.


Errata Update SkepticalScience: Gavin Schmidt let me know that in the first version of this post, I used gigatons of carbon instead of gigatons of methane. I mistakingly read the Shakhova paper as an injection of carbon. Since the molecular weight of carbon is 12 g/mol, and CH4 is 16 g/mol, then 1 GtC=1.33 GtCH4. The figure in the post has been revised accordingly and doesn't impact the argument here.


Related

- Arctic Methane Release: "Economic Time Bomb"
http://arctic-news.blogspot.com/2013/07/arctic-methane-release-economic-time-bomb.html

- Methane Hydrates
http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

- Arctic Methane FAQ
http://arcticmethane.blogspot.com/p/faq.html


- Listen to Paul Beckwith speak on Gorilla-radio.com
http://www.gorilla-radio.com/audio/Gorilla_Radio_2012-2013-08-13-24647.mp3

The Social Tipping Point

by Paul Beckwith

Abrupt Climate Change is happening today, big time!

Abrupt climate change. It is happening today, big time. The northern hemisphere atmospheric circulation system is doing its own thing, without the guidance of a stable jet stream. The jet stream is fractured into meandering and stuck streaked segments, which are hoovering up water vapor and directing it day after day to unlucky localized regions, depositing months or seasons worth of rain in only a few days, turning these locales into water worlds and trashing all infrastructure like houses, roads, train tracks and pipelines. Creating massive sinkholes and catastrophic landslides. And climate change is only getting warmed up.

In the Arctic methane is coming out of the thawing permafrost. Both on land and under the ocean on the sea floor. The Yedoma permafrost in Siberia is now belching out methane at greatly accelerated rates due to intense warming. The collapsing sea ice in the Arctic Ocean is exposing the open ocean to greatly increased solar absorption and turbulent mixing from wave action due to persistent cyclonic activity. Massive cyclonic activity will trash large portions of the sea ice if positioned to export broken ice via the Fram Strait.

We have lost our stable climate

What does it all mean? There is no new normal? Far from it. We have lost our stable climate. Likely permanently. Rates of change are greatly exceeding anything in the paleorecords. By at least 10x, and more likely >30x. We are heading to a much warmer world. The transition will be brutal for civilization.

Can we avoid this? Stop it? Probably not? At least with climate reality being suppressed by corporations and their government employees. With their relentless push for more and more fossil fuel infrastructure and mining and drilling.

What else can we expect as we negotiate our abrupt transition in climate to a much warmer world?

Craziness, in a nutshell. Temperatures over land surfaces in the far north have been consistently over 25 C for weeks, due to persistent high pressure atmospheric blocks leading to clear skies and unblocked solar exposure. Water temperatures in rivers and streams in the far north have resulted in large fish kills as their ecological mortality thresholds have been exceeded. Many other regions are experiencing strange incidences of animal mortality. Mass migrations of animals towards the poles are occurring on land and sea, at startling rates, in an effort for more hospitable surroundings for survival. Shifting food source distributions is causing even hardier, less vulnerable species to be severely stressed. For example, dolphins are being stranded or dying, birds are dropping out of the sky, and new parasites and bacteria are proliferating with warmer temperatures.

In regions of the world undergoing severe droughts the vegetation and soils are drying and fires are exploding in size, frequency, and severity. Especially hard-hit are large regions of the US southwest, southern Europe, and large swaths of Asia. Who knows if forests that are leveled by fire will eventually be reforested; it all depends on what type of climate establishes in the region.

What about coastal regions around the world and sea levels? Not looking too good for the home team. In 2012 Greenland tossed off about 700 Gt (Gt=billion tons) of sea ice, from both melting and calving. As the ice melts it is darkening from concentrated contaminants being exposed, from much greater areas of low albedo meltwater pools, and from fresh deposits of black carbon ash from northern forest fires. Even more worrying are ominous signs of increasing movement. GPS sensor anchored to the 3 km thick glaciers hundreds of km from the coast are registering increased sliding. Meltwater moulins are chewing through the ice from the surface to the bedrock and are transporting heat downward, softening up the ice bonded to the bedrock and allowing sliding. Eventually, large chunks will slide into the ocean causing tsunamis and abrupt sea level rises. Many regions of the sea floor around Greenland are scarred from enormous calving episodes in the past.

The Social Tipping Point

On a positive note, this knowledge of our changing climate threat is filtering out to greater numbers of the slumbering public that has been brainwashed into lethargy by the protectors of the status quo. As more and more people see the trees dying in their back yards and their cities and houses and roads buckling under unrelenting torrential rains they are awaking to the threat. And there will be a threshold crossed and a tipping point reached in human behavior. An understanding of the reality of the risks we face. And finally global concerted action. To slash emissions. And change our ways. And retool our economies and reset our priorities. And not take our planet for granted.

Paul Beckwith is a part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. He teaches second year climatology/meteorology. His PhD research topic is “Abrupt climate change in the past and present.” He holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life.

The above compilation of IPCC and NOAA images is by Peter Carter, who adds the following comment:

I agree. The IPCC in 2007 said: "The concentration of CO2 is now 379 parts per million (ppm) and methane is greater than 1,774 parts per billion (ppb), both very likely much higher than any time in at least 650 kyr (during which CO2 remained between 180 and 300 ppm and methane between 320 and 790 ppb). The recent rate of change is dramatic and unprecedented; increases in CO2 never exceeded 30 ppm in 1 kyr – yet now CO2 has risen by 30 ppm in just the last 17 years."

By definition this is abrupt heating. because atmospheric GHG concentration correlates directly with radiative forcing. CO2 is now 397 ppm and methane is now 1830 ppb ! It follows that the rate of ice being melted will also (as it looks) be unprecedented. The only force we have against mad fossil fuel pushing governments is accountability. They have to be made to face the full terrible consequences of their action on energy and inaction on climate. They are destroying the world.

Climate, the “new normal” and the Australian elections

by Andrew Glikson

“The 1st Law of Humanity: Don’t kill your children!”
(Hans Joachim Schellnhuber, chief climate advisor to the German Government).
http://www.pik-potsdam.de/news/inshort/files/Schellnhuber-keynote-COP18-state-dinner-Doha.pdf

“Earth is worth £3,000 trillion, according to scientist's new planet valuing formula”
http://www.dailymail.co.uk/sciencetech/article-1361145/Earth-worth-3-000-trillionaccording-scientists-new-planet-valuing-formula.html

Earth rising over the Moon - http://www.nasa.gov/vision/earth/features/bm_gallery_4.html

That people can be duped to accept the destruction of the atmosphere – the lungs of the biosphere - is something no science-fiction has yet described, yet, as the summary of the scientific evidence presented below indicates, is now science-fact.

By the end of the 20th century powerful vested interests, including corporations and few billionaires and their political mouthpieces, combined to promote saturation of the terrestrial atmosphere with carbon dioxide, in contravention of climate science, are experiencing a Pyrrhic victory oblivious to the unfolding tragedy.

Nothing exemplifies these developments more than the current Australian elections. An internet search for the terms ‘Australia’ ‘elections’ and ‘climate change’ recovers very little in terms of party policies

(http://theconversation.com/why-labor-should-fight-the-2013-election-on-climate-change-13865, http://www.theguardian.com/environment/southerncrossroads/2013/aug/05/australian-election-2013-climate-change).

For example, the words ‘climate change’ (or ‘global warming’) were not even mentioned in a recent ABC prime time QandA pre-election program, in which the opposition shadow environmental minister participated. A cosmetic carbon price is threatened by the largest party, nor do many refer to Australia being on track to become an equivalent of Saudi Arabia in terms of global fossil fuel (coal) exports.

Featuring heavily in the current election campaign are the potential financial debts of future generations but little is said about the environmental debt – life under 4 degrees Celsius (above pre-industrial temperatures). Only a minor party is focused on the climate calamity.

When the theory of ‘economic rationalism’ emerged, pricing every item including cultural and spiritual values, a question arose as to “The price of the Earth”, currently estimated as 3000 trillion pounds (http://www.dailymail.co.uk/sciencetech/article-1361145/Earth-worth-3-000-trillion-according-scientists-new-planet-valuing-formula.html).

A Faustian Bargain is on (http://www.huffingtonpost.com/dr-james-hansen/doubling-down-on-our-faustian-bargain_b_2989535.html). What commenced some 20 years ago as a scientific debate has deteriorated to media-dominated pseudo-debate replete with misrepresentations of the science. Below I highlight the principal line of evidence emerging from geological and paleoclimate science:

Critical to the evolution of life since at least ~3.5 billion years-ago, from where the earliest known stromatolites and micro-fossils are recorded [1], are the combined effects of solar insolation and atmospheric chemistry, which control temperatures (-90° to +58°C) and the state of H2O at the surface as vapor, ice or liquid – the latter allowing life. Compensating for the continuous release of CO2 from the crust and mantle by volcanic eruption are tectonic, weathering and sedimentary processes that recycle the crust and lock CO2 in carbonates and organic matter subducted into the mantle [2], preventing a run-away build-up of atmospheric greenhouse gases (the Venus syndrome [3]).

Movement of carbon between land, atmosphere, and oceans in billions of tons of carbon per year. Yellow numbers are natural fluxes, red are human contributions in billions of tons of carbon per year. White numbers indicate stored carbon.
http://en.wikipedia.org/wiki/Carbon_cycle

The histories of the atmosphere, the oceans and life are thus closely intertwined. The atmosphere, mediating the carbon, oxygen and nitrogen cycles (see above image), acting as the lungs of  the biosphere, regulates an aqueous medium where microbiological metabolic processes occur, from chemo-bacteria around volcanic fumaroles, to nanobes in deep crustal fractures, to nearsurface phototrophs. From ~420 million years ago the advent of land plants ensued in flammable carbon-rich land surfaces interfaced with an oxygen rich atmosphere, ensuing in a combustible combination [4]. Repeatedly through geological history volcanic eruptions and asteroid impacts triggered major release of greenhouse gases (GHG) from the crust as well as extensive surface fires, major climate changes and mass extinctions of species [5].

Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including
the Paleocene-Eocene Thermal Maximum, Oligocene, Miocene, late Pliocene, Eemian (glacial termination),
Dansgaard-Oeschger cycles, Medieval Warming Period, 1750-2012 and 1975-2012 periods.

The current rise of atmospheric GHG at an unprecedented rate (see above image), defines the Anthropocene [6] as an oxidation event, a new geological era triggered by a species which has uniquely mastered ignition, excavating and releasing hundreds of billions of tons (more than 560 GtC) of carbon from geological formations into atmosphere. The consequences for the biosphere, referred to as the 6th mass extinction of species [7], are leading to a tragedy for human ideals and for nature.

Is the Anthropocene event horizon a purely pre-determined natural? Alternatively, where does responsibility lie?

On the scale of the species, once the energy output of the genus Homo was magnified through combustion by many orders of magnitude, the phenomenon can be deemed an inherent part of natural evolution. This may lead to a deterministic conclusion: It is unlikely to expect any species to be as perfectly wise and responsible as to be able to constrain the effects of its invention.

Where does free will lie? On the scale of modern civilization, since the greenhouse effect [8] and its underlying laws of physics and chemistry [9] have been identified in the 19th century, the question arises to what extent would societies and their leaders accept the implications of the science for human industry? Will the scientific method itself and the enlightenment [10] form the basis of future decisions?

In so far as government and corporate decisions are influenced by misconceptions and misrepresentations of the science, as an excuse for inaction, responsibility for the rapidly unfolding shift in the state of the terrestrial climate lies with the shortsightedness of Homo sapiens.

It is the peer review system which forms the venue for science communications. However, toward the end of the 20th century a multitude of media pieces and hundreds of websites began proliferate pseudoscience notions ignorant of the principles of science in general and of climate science in particular. Nor, in general, were practicing climate scientists allowed the same access to the popular media to communicate their research, a situation aggravated by conspiracy theories and ad-hominem aimed against climate scientists.

The lesson of numerous attempted debates since 2005 with those who deny the reality of global warming, or attempt to attribute it to natural non-human factors, show these notions cannot be dissuaded by any amount of evidence [11, 12, 13]. Numerous erroneous claims continue to be made. To cite just a few examples:

• The claim, as if temperature rise preceded CO2 rise during the glacial terminations therefore the current rise of temperature is not the result of CO2 rise [14], cannot be sustained. The effects of CO2 and temperature variations are intertwined. During the last ~400,000 years glacial eras were terminated by solar maxima, affecting decreased CO2 solubility in warming water and thereby a rise in CO2 levels of the atmosphere. By contrast climate developments since the 18th century, when negligible or no rise in insolation occurred, were triggered by the anthropogenic greenhouse effect of the release of >560 billion ton carbon, consistent with the basic laws of physics [9]. 
• The claim as if global warming represents recovery from the ‘Little Ice Age’ (LIA) cannot be sustained: The LIA was caused by a near-cessation of sunspot activity during ~1650-1700, depressing global temperatures by ~0.2-0.3°C relative to preceding periods. By contrast, following a lull, global warming from about 1975 tracked toward more than 1.5°C over the continents relative to pre-industrial temperatures [15]. 
• Claims related to the cosmic rays flux (CRF) effects: A dominant solar effect on the climate since 1970 is ruled out by measurements of solar radiation [16]. The incidence of cosmic rays, which oscillate reciprocally with the 11 years sunspot cycle, has been shown to have minor effects on cloud nucleation and has not varied significantly since the mid-20th century [17]. 
• The claim as if carbon dioxide is emitted mainly from volcanoes: According to the United States Geological Survey (2012) sub-aerial and sub-marine volcanism emits approximately 150 – 260 million tons CO2 per-year whereas anthropogenic emissions total about 35 billion tons CO2/per-year [18]. 
• Mars warming [19]: The argument invokes unknown solar system-wide phenomena, despite measurements of solar radiation and the cosmic ray flux which show little change since the mid-20th century. Some temperature fluctuations in Mars are known to be related to dust storms. 

To the extent that misleading pseudoscience of this nature continue to help governments and vested interests to promote the combustion of fossil fuels (cf. ‘the future of coal’ [20]), at the expense of the future of the atmosphere, the unthinkable consequences of 4° Celsius and higher [21] on the terrestrial atmosphere-ocean system have already commenced through a series of extreme weather events, reflecting the rise in energy/temperature of the atmosphere/ocean system [22] – the “new normal” [23].

References

1. http://www.nature.com/nature/journal/v441/n7094/abs/nature04764.html
2. http://www.platetectonics.com/book/page_12.asp
   http://www.columbia.edu/~vjd1/carbon.htm
3. http://en.wikipedia.org/wiki/Runaway_greenhouse_effect
4. http://www.sciencemag.org/content/324/5926/481.abstract
5. http://www.skepticalscience.com/Earths-five-mass-extinction-events.html
6. http://rsta.royalsocietypublishing.org/content/369/1938/842.abstract
7. http://edition.cnn.com/2002/TECH/science/08/23/green.century.mass.extinction/index.html 
8. http://www.aip.org/history/climate/co2.htm
9. https://en.wikipedia.org/wiki/Black-body_radiation
10. http://plato.stanford.edu/entries/enlightenment/
11. http://www.bookdepository.com/Merchants-of-Doubt-NaomiOreskes/9781608193943?redirected=true&gclid=CPe3uYiZ4bgCFUpZpQodIhcAvQ
12. http://www.amazon.com/Climate-Change-Denial-Heads-Sand/dp/1849713367
13. http://www.amazon.com/A-Short-Introduction-Climate-Change/dp/11076187625
14. http://www.skepticalscience.com/co2-lags-temperature.htm
15. http://berkeleyearth.org/
16. http://www.mps.mpg.de/homes/natalie/PAPERS/warming.pdf
    http://www.sciencedirect.com/science/article/pii/S0012821X06004328
17. http://www.pik-potsdam.de/~stefan/Publications/Journals/rahmstorf_etal_eos_2004.html http://www.sciencedirect.com/science/article/pii/S1364682603000415
18. http://volcanoes.usgs.gov/hazards/gas/climate.php
19. http://www.skepticalscience.com/global-warming-on-mars.htm
20. http://www.miningaustralia.com.au/news/coal-mining-has-a-future-combet
21. http://www.pik-potsdam.de/news/press-releases/4-degrees-briefing-for-the-world-bank-therisks-of-a-future-without-climate-policy
    http://www.spiegel.de/international/world/merkelclimate-advisor-blasts-politicians-for-doing-too-little-a-868024.html
    http://www.sciencedaily.com/releases/2012/11/121119104842.htm 
22. http://www.nature.com/nclimate/journal/v2/n7/full/nclimate1452.html
    http://www.pnas.org/content/early/2012/07/30/1205276109.full.pdf+html
    http://www.realclimate.org/index.php/archives/2012/08/extreme-metrics/
    http://www.aph.gov.au/parliamentary_business/committees/senate_committees?url=ec_ctte/extreme_weather/index.htm 
23. http://blog.ucsusa.org/bigger-hotter-and-longer-wildfires-are-the-new-normal-as-theclimate-changes-in-the-west-183

Another Arctic cyclone brewing

Another cyclone is brewing in the Arctic. Below are Naval Research Laboratory projections of sea ice drift a few days ahead.

[ click on image to enlarge ]

The image below, from Danmarks Meteorologiske Institut (DMI), shows surface pressure over the Arctic Ocean on August 7, 2013.

from: http://ocean.dmi.dk/arctic/weather/arcticweather.uk.php

Below are two projections of pressure and wind direction for August 11 and August 15, 2013.

edited screenshots from animation at weather-forecast.com

A further post with more details on this cyclone will be added soon.

Methane levels keep rising rapidly

Global methane levels keep rising rapidly. Earlier this month, the post Methane as high as 2303 ppb quickly became outdated and was updated with the post Methane as high as 2349 ppb. Meanwhile, though, the most recent data show that the highest level reached on August 5, 2013, was 2442 ppb.

This recent peak level is only slightly below the highest peak level this year, which was a level of 2475 ppb reached on April 26, 2013, which at the time was considered a one-off local peak.

These recent high peak levels do seem to be more than just local peaks, given that high levels of methane are suddenly recorded over much of the globe, as described in the earlier post Methane as high as 2349 ppb.

The image on the right (added later, editor) also shows that not only have peak levels greater than 2300 ppb appeared since late June 2013, but also have the highest daily mean methane levels suddenly increased by about 20 ppb recently.

The image below shows over how many square kilometers methane was present at over 1950 ppb globally over the past few days.

The numbers also feature in the image on the left and they illustrate the huge jump that took place somewhere between July 31 and August 1, 2013.

It may be that there has indeed been a huge sudden increase in methane.

On the other hand, it could also be that EuMetSat implemented a re-calibration on July 31. After all, EuMetSat announced recently that IASI Level 2 products from Metop-B had been declared operational and would be available on GTS from 31 July.

Such a re-calibration (if it did indeed take place) does appear to make sense, given the discrepancy between IASI's mean methane levels and the levels recorded at stations. Below are measurements taken at Mauna Loa, Hawaii, which given the station's location close to the equator are often taken as global averages (flasks on the left, and hourly average in situ measurements on the right).

[ click on image to enlarge ]
from: http://www.esrl.noaa.gov/gmd/dv/iadv/index.php

Mauna Loa methane levels are often quoted to be about 1830 ppb, whereas the highest IASI mean levels did barely cross the 1800 ppb mark earlier this year. Since the jump, the highest IASI mean levels have suddenly been significantly higher (20 ppb more, at around 1820 ppb).

Even so, the current situation is very worrying. High levels of methane are present not only on the Northern Hemisphere, but also on Antarctica and over the oceans on the Southern Hemisphere, as shown in a recent post. And of course, the situation remains most threatening in the East Siberian Arctic Shelf (ESAS), as described at the Methane-hydrates blog and and at Arctic Methane FAQ.