The time has come to spread the message

[ click on image to enlarge ]

Above image shows methane rising from the seafloor of the Arctic Ocean on December 3, 2013, and entering the atmosphere, reaching levels as high as 2425 parts per billion (ppb). Last month, on November 9, 2013, methane reached levels as high as 2662 ppb.

The image below gives an idea of the height of this level, compared to historic levels, and how fast levels of methane (CH4) have been rising compared to levels of two other greenhouse gases, i.e. carbon dioxide (CO2) and nitrous oxide (N2O).

While CO2 levels are in ppm and CH4 in ppb, they are directly comparable, in that a CH4 cloud, 5 years after its abrupt
release into the atmosphere over the Arctic Ocean, may have shrunk to 20% of its original size, yet will over those 5 years
have exercized local warming more than 1000 times stronger than the global warming potency of the same mass of CO2.  

Above graph shows the dramatic rise in the levels of greenhouse gases over the past few centuries. Almost half of all global warming results from a 3 Gt rise in methane since the 1750s, as described in the recent post Quantifying Arctic Methane.

Why worry about methane rising from the seafloor in the Arctic? Sediments underneath the Arctic Ocean hold vast amounts of methane. Just one part of the Arctic Ocean alone, the East Siberian Arctic Shelf (ESAS, see map below), holds up to 1700 Gt of methane. A sudden release of just 3% of this amount could add over 50 Gt of methane to the atmosphere, and experts consider such an amount to be ready for release at any time.

Just let those figures sink in for a moment. Total methane burden in the atmosphere now is 5 Gt. The 3 Gt that has been added since the 1750s accounts for almost half of all global warming. The amount of carbon stored in hydrates globally was in 1992 estimated to be 10,000 Gt (USGS), while a more recent estimate gives a figure of 63,400 Gt (Klauda & Sandler, 2005). The ESAS alone holds up to 1700 Gt of methane in the form of methane hydrates and free gas contained in sediments, of which 50 Gt is ready for abrupt release at any time.

Imagine what kind of devastation an extra 50 Gt of methane could cause. Imagine the warming that will take place if the methane in the atmosphere was suddenly multiplied by 11. Whiteman et al. recently calculated that such an event would cause $60 trillion in damage. By comparison, the size of the world economy in 2012 was about $70 trillion.

Smaller releases of methane in the Arctic come with the same risk; their huge local warming impact threatens to further destabilize sediments under the Arctic Ocean and trigger further methane releases, as illustrated by the image below.

Victor Hugo

In the light of these figures, there is no question that this is important and that dramatic changes are needed to reduce such dangers. Indeed, the only question is what kind of changes are needed.

The challenges may seem huge, the opposition to change may seem formidable. Yet despite the saber rattling of armies, and despite covert efforts by powerful conglomarates and vested interests to resist change, common sense will prevail, because nothing is as strong as an idea whose time has come. [“On résiste à l'invasion des armées; on ne résiste pas à l'invasion des idées.” -- From: Histoire d'un crime, Victor Hugo.]

As the prospect of climate catastrophe becomes ever more apparent and as the political imperative to take comprehensive and effective action becomes ever more urgent and obvious, this message will spread and the winds of change will grow stronger day after day. Be part of the solution and spread the message!

Post by Sam Carana.

Arctic Methane Impact

The image below covers a period of just over one day. On November 26, 2013, peak readings were as high as 2392 ppb.

The green circle highlights an area with high methane levels just north of Greenland. This methane likely originates from hydrates along the fault line that crosses the Arctic Ocean. As the Naval Research Laboratory animation below shows, sea ice in that area is rather thick. How it is possible for the methane to appear there? The answer must be, it seems, that there is so much movement in the sea ice in this area, that there are many cracks through which the methane can rise.

Above animation shows how a huge part of the sea ice, meters thick, is pushed along the edges of Greenland into the Atlantic Ocean, as a result of strong winds, as also illustrated by the animation below.

Methane has now been showing up prominently over the entire Arctic Ocean for more than a month and it doesn't look like this situation is coming to an end soon. The animation shows methane over the Arctic Ocean over a period of six days, with each frame covering a period of one day.

What is the impact of all this methane on temperatures over the Arctic? The NOAA image below shows surface temperature anomalies for a 30-day period.

When temperatures are averaged over longer periods, peaks will obviously show up less severe. Yet, on above image an area shows up in the Arctic where anomalies have averaged 15 degrees Celsius or more over this 30-day period.

When looking at individual days, anomalies of over 20 degrees Celsius can show up, on above image over quite a large area. While the weather can vary a lot and depends on a lot of factors, there is no doubt that the methane cloud hanging over the Arctic Ocean will have contributed to such anomalies. Since this methane isn't just going away soon, this spells bad news for what is ahead in the Arctic.

And while most efforts to contain global warming focus on ways to keep global temperature from rising by more than 2°C, a polynomial trendline already points at global temperature anomalies of 5°C by 2060. Even worse, a polynomial trend for the Arctic shows temperature anomalies of 4°C by 2020, 7°C by 2030 and 11°C by 2040, threatening to cause major feedbacks to kick in, including albedo changes and methane releases that will trigger runaway global warming that looks set to eventually catch up with accelerated warming in the Arctic and result in global temperature anomalies of 20°C+ by 2050.

Quantifying Arctic Methane

The paper 'Ebullition and storm-induced methane release from the East Siberian Arctic Shelf', was published in the journal Nature Geoscience on November 24, 2013.

The paper is dedicated “to the memory of the crew of Russian vessel RV Alexei Kulakovsky”, the 11 people who died when their tugboat perished in efforts to assist the scientists who were measuring methane from a fishing boat.

The research team used methods including drilling into the seabed of the Laptev Sea and sonar to analyse methane releases in the water, seeking to quantify the significant amounts of methane that are bubbling up from the sea bed in the East Siberian Arctic Shelf (ESAS, rectangle on image below), the area with shallow seas north of Siberia covering some 810,800 square miles (2.1 million square kilometers). By comparison, the United States (land and water) covers an area of nearly 10 million square kilometers.

“We have proven that the current state of subsea permafrost is incomparably closer to the thaw point than terrestrial permafrost, and that modern warming does contribute to warming the subsea permafrost,” says Natalia Shakhova, adding that an increase in storminess in the Arctic would further speed up the release of methane.

The scientists estimate, on the basis of the sonar data, that “bubbles escaping the partially thawed permafrost inject 100–630 mg methane square meters daily into the overlying water column”, and suggest that “bubbles and storms facilitate the flux of this methane to the overlying ocean and atmosphere, respectively”.

Some 17 teragrams (Tg or Mt) of methane escapes annually from the ESAS, said Natalia Shakova, lead study author and a biogeochemist at the University of Alaska, Fairbanks. This is an upgrade from the earlier estimate of 8 Tg of annual outgassing from the ESAS (Shakhova et al. 2010).

While including a reference to this earlier paper (Shakhova et al. 2010), the IPCC did give much lower estimates for emissions from all hydrates globally and from permafrost (excl. lakes and wetlands), i.e. 6 and 1 Tg per year, respectively.

And by comparison, IPCC estimates for all global methane emissions from manmade and natural sources go from 526 Tg per year to 852 Tg per year, of which 514 to 785 Tg per year is broken down (mostly by hydroxyl).

Sadly, as discussed in an earlier post, the IPCC has decided NOT to warn people about the danger that methane from hydrates will lead to abrupt climate change within decades. Yet, when entering the data by Shakhova et al. in a spreadsheet, a linear trendline (green line on image below) shows methane release in the ESAS reaching 20 Tg by 2013 and 26 Tg by 2015.

An exponential trendline (red/blue line) shows methane release in the ESAS reaching 22 Tg by 2013 and 36 Tg by 2015. Extending that same exponential trendline further into the future shows methane release in the ESAS reaching 2 Gt by the year 2031 and 50 Gt by the year 2043.

Note that accumulated totals over the years will be much higher than the annual release. While the IPCC gives methane a perturbation lifetime of 12.4 years, this methane will persist in the Arctic for much longer because its release is concentrated in the Arctic where hydroxyl levels are also very low.

Globally, IPCC/NOAA figures suggest that abundance of methane in the atmosphere currently (2013) is 1814 parts per billion (ppb), rising with 5 or 6 ppb annually, and that this rise is caused by a difference of 8 Tg between the methane emitted (548 Tg, top-down estimate) and broken down annually (540 Tg, top-down estimate). It is also worth noting that the IPCC has increased methane's global warming potential to 86 over 20 years with climate-carbon feedbacks, while there are reasons to assume that methane's impact, especially short-term and in case of large abrupt releases in the Arctic, is even stronger. Furthermore, the IPCC now gives methane a Radiative Forcing (RF) of 0.97 W/m^-2 (up from 48 W/m^-2 in 2007 and relative to 1750), as illustrated by the image below.

According to the IPCC, methane levels in 1750 and 2011 were 722 ppb and 1803 ppb, respectively. The total global methane burden is estimated to be about 5 Gt, i.e. 5 petagrams (Pg) or 5,000 Tg. A back-of-envelope calculation sugests that the methane burden in 1750 was 5 Gt x (722 : 1803) = 2 Gt. Furthermore, methane's 0.97 W/m^-2 RF is 42% of the total RF 2.29 W/m^-2. Therefore, the 3 Gt of methane that has been added to the atmosphere since 1750 is responsible for almost half of all the global warming since that time.

For now, the IPCC's estimated annual increase in global methane levels may seem small, but this figure appears to be based on low-altitude data collected over the past few decades. The total methane burden may already be rising much more rapidly, also because methane is rising in the atmosphere, increasing the burden especially at higher altitudes, as evidenced by the increasing occurence of noctilucent clouds. In other words, the 8 Tg estimate may reflect older data related to changes in lower-altitude measurements only, but the total methane burden may well be rising much more rapidly due to increases at higher altitudes. Further analysis comparing satellite data at different altitudes over the years could verify this.

An earlier post estimated that as much as 2.1 Mt (or 2.1 Tg) of methane could have been released abruptly end 2011. If you compare the animation of that earlier post with the recent animation, then current abrupt releases from the sea floor of the Arctic Ocean appear to be even higher.

As said, methane releases from the Arctic Ocean may for now seem small and may not yet make global temperatures rise much, but nonetheless the methane cloud hanging over the Arctic is contributing to warming locally. Combined with the increased likelyhood of extreme weather and rapid loss of ice and snow cover in the Arctic, this could make water temperatures in the Arctic Ocean rise even further, causing further destabilization of methane hydrates. Furthermore, the mechanical force of methane release from hydrates (rapidly expanding 160 times in volume) itself can also contribute to hydrate destabilization. Seismic activity could also lead to destabilization. Indeed, there are many factors that could contribute to exponential rise of methane release from the Arctic Ocean, as discussed in the post on methane hydrates, which calls for comprehensive and effective action, such as discussed at the Climate Plan blog.


References

Ebullition and storm-induced methane release from the East Siberian Arctic Shelf, by Natalia Shakhova, Igor Semiletov, Ira Leifer, Valentin Sergienko, Anatoly Salyuk, Denis Kosmach, Denis Chernykh, Chris Stubbs, Dmitry Nicolsky, Vladimir Tumskoy & Örjan Gustafsson (2013)
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2007.html

Arctic storms speed up release of methane plumes, by Fred Pearce
http://www.newscientist.com/article/dn24639-arctic-storms-speed-up-release-of-methane-plumes.html

Twice as Much Methane Escaping Arctic Seafloor, by Becky Oskin
http://www.livescience.com/41476-more-arctic-seafloor-methane-found.html

Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic shelf, by Natalia Shakhova, Igor Semiletov, Anatoly Salyuk, Vladimir Yusupov, Denis Kosmach, and Örjan Gustafsson, in: Science, 327, 1246-1250 (2010).
http://www.sciencemag.org/content/327/5970/1246.abstract

On carbon transport and fate in the East Siberian Arctic land–shelf–atmosphere system, by Semiletov et al. (2012)
http://iopscience.iop.org/1748-9326/7/1/015201

Intergovernmental Panel on Climate Change (IPCC), AR5 Working Group 1
http://www.climatechange2013.org/

Post by Sam Carana.

High Methane Levels all over Arctic Ocean

High levels of methane were recorded all over the Arctic Ocean on November 19, 2013, as illustrated by the image below. The image also shows that most methane was present over the fault line that crosses the Arctic Ocean (as also indicated on the inset).

[ Click on image to enlarge ]

A recent post described that more methane may actually be present closer to the North Pole than IASA images may indicate. This because measurements can be obscured by clouds. If no data are recorded over a certain area, no methane levels will show up on images for the respective area. This was the case on November 17, 2013, when the Arctic Ocean was quite cloudy, and little or no data were recorded for the center of the Arctic Ocean.

On November 19, 2013, the sky was much clearer, resulting in a lot of data from the center of the Arctic Ocean, as also illustrated by the image below.

In conclusion, high methane levels can actually be present all over the Arctic Ocean, even when images only show high levels in some areas.

An earlier post described how the sea ice can act as a shield, especially when the ice is more than one meter thick.

How does this rhyme with the above image? The November 19, 2013, Naval Research Laboratory image on the right shows that the sea ice was meters thick in some locations where methane shows up on the top image.

So, is methane actually rising from the seafloor of the entire Arctic Ocean, perforating even the thickest ice and entering the atmosphere all across the Arctic Ocean? Or, if thick sea ice does act as a shield, how did methane appear all over the Artic Ocean in such huge quantities?

The images on the right indicate that the methane may actually only rise from the seafloor in a few locations.

As the top image on the right says, the Coriolis Effect can make methane over the Laptev Sea end up over Canada a few days later. So, methane may not be perforating the sea ice in the north of Canada, but may instead originate from elsewhere in the Arctic.

The animation underneath shows methane readings from November 9 to 19, 2013, with each of the 20 frames covering a period of 24 hours and with frames following each other up 12 hours after each other. As the animation shows, it looks like methane is predominantly entering the atmosphere at specific locations, most notably along the fault line that crosses the Arctic Ocean.

It may well be that this methane ends up all the way in Baffin Bay, to the left of Greenland. Since the Greenland ice sheet is 3 kilometers (1.9 miles) thick, this may form a natural barrier that keeps the methane there, also helped by winds rising vertically from Baffin Bay to well above Greenland's mountains. Methane may also be traveling under the sea ice, all the way from the Gakkel Ridge and the Laptev Sea right to Baffin Bay.

On the other hand, it could also be that hydrates underneath the sea bed of Baffin Bay itself have become destabilized and that, since the ice over Baffin Bay is rather thin, methane has no problem perforating the ice and is entering the atmosphere there in huge quantities.

Either way, the end-conclusion is that the methane that is now showing up all over the Arctic Ocean, is rising from the seafloor, due to destabilization of sediments that hold huge amounts of methane in the form of free gas and hydrates. As warming in the Arctic continues to accelerate, the danger is that this will cause more methane to rise from the seafloor and that the methane itself will contribute to warming in the Arctic, in a deadly spiral set to cause abrupt climate change at a devastating scale.

Post by Sam Carana.