Methane

Images by Sam Carana from the Methane page at http://arctic-news.blogspot.com/p/methane.html




1. Methane, Faults and Sea Ice

Massive amounts of methane venting from the seabed, penetrating the sea ice, and entering the atmosphere over the Arctic Ocean. Faultlines indicate a further danger, i.e that earthquakes could trigger clathrate destabilization.

For an animated version of this image, go to the post Methane, Faults and Sea Ice

Image #1. from:
Methane, Faults and Sea Ice
http://arctic-news.blogspot.com/2013/11/methane-faults-and-sea-ice.html



2. Biggest Story of 2013 (Methane over Arctic Ocean)

The 'Biggest Story of 2013' image shows cumulative methane for the period December 26, 2013, 11:00 am to December 29, 2013, 11:05 pm.

Biggest story of 2013: Huge methane releases from the seafloor of the Arctic Ocean
Image #2. from:
The Biggest Story of 2013
http://arctic-news.blogspot.com/2013/12/the-biggest-story-of-2013.html
facebook link:
https://www.facebook.com/photo.php?fbid=10153641610950161



3. Methane bubbling up in Baffin Bay

Huge amounts of methane can be carried out of the Arctic Ocean by the exit current through Baffin Bay.

Methane bubbling up in Baffin Bay
Image #3. from:
Methane emerges from warmer areas
http://arctic-news.blogspot.com/2013/12/methane-emerges-from-warmer-areas.html
facebook link:
https://www.facebook.com/photo.php?fbid=10153590729830161



4. Methane emissions estimates

Sam Carana in 2014: "The amounts of methane being released from hydrates will be greater than the methane that actually reaches the atmosphere. To put a figure on the latter, my estimate is that emissions from hydrates and permafrost currently amount to 100 Tg annually, a figure that is growing rapidly. This 100 Tg includes 1 Tg for permafrost, similar to IPCC estimates."


Image #4. from:
High methane levels over the Arctic Ocean on January 14, 2014
https://arctic-news.blogspot.com/2014/01/high-methane-levels-over-the-arctic-ocean-on-january-14-2014.html



5. Potential Release

5.a Potential Release: How much methane could be released, say, within a few years


Image #5.a from:
Edge of Extinction
https://arctic-news.blogspot.com/2015/01/edge-of-extinction.html
and from:
FAQ
https://arctic-news.blogspot.com/p/faq.html#10



5.b Potential Release: Methane by Numbers

Sediments underneath the Arctic Ocean hold vast amounts of methane. Just one part of the Arctic Ocean alone, the East Siberian Arctic Shelf (ESAS, rectangle on 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 (see above image).


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 the (net) total global warming caused by people. 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. Gail Whiteman, Chris Hope and Peter Wadhams in 2013 calculated that such an event would cause $60 trillion in damage, assing that, by comparison, the size of the world economy in 2012 was about $70 trillion.

Image #5.b from:
The time has come to spread the message
https://arctic-news.blogspot.com/2013/12/the-time-has-come-to-spread-the-message.html



5.c Potential Release: ESAS (East Siberian Arctic Shelf) 

A more detailed image of the above inset is below.



Image #5.c was created with content from a recent paper by Natalia Shakhova et al.
The image was part of the post:
When will we die?
https://arctic-news.blogspot.com/2019/06/when-will-we-die.html




6. Historic Methane Levels

6.a Historic Methane Levels - The Methane Hockeystick

Over the past 420,000 years, temperatures typically moved up and down by roughly 10°C or 18°F between glacial and interglacial phases, suggesting that a 100 ppm rise of carbon dioxide and 300 ppb rise of methane go hand in hand with a 10°C temperature rise. By implication, current levels of carbon dioxide in the atmosphere appear to have us locked in for a future temperature rise of more 10°C. When looking at methane, the equation appears to be even worse, both regarding the size of the temperature rise and regarding the timescale over which this could eventuate.

Vostok ice core data for CO2 are in this graph http://cdiac.ornl.gov/trends/co2/graphics/vostok.co2.gif
the data have been available since 2003, e.g. at http://cdiac.ornl.gov/ftp/trends/co2/vostok.icecore.co2

Image #6.a from:
Mean methane levels reach 1800 ppb
https://arctic-news.blogspot.com/2013/06/mean-methane-levels-reach-1800-ppb.html




6.b Historic Methane Levels - The Methane Hockeystick

As the updated image below illustrates, a 10°C temperature rise from 1750 is in line with the high level of forcing that is caused by the rapid rise in the levels of greenhouse gases recently.


Carbon dioxide levels have been above 400 ppm for years. Methane levels above 1900 ppb were recorded in September 2018. Such high levels are more in line with a 10°C higher temperature, as illustrated by the above graph based on 420,000 years of ice core data from Vostok, Antarctica, research station.

Image #6.b is from:
What Does Runaway Warming Look Like?
https://arctic-news.blogspot.com/2018/10/what-does-runaway-warming-look-like.html



6.c Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide

While carbon dioxide emissions get a lot of attention (and they definitely must be cut rapidly and dramatically), the rise of methane is possibly even more worrying. The image below shows the historic rise (1750-2015) of methane (CH4), carbon dioxide (CO₂) and nitrous oxide (N2O).
Historic rise of methane, carbon dioxide and nitrous oxide

According to NOAA data, annual mean global methane grew from 2004-2013 by an average of 3.75 ppb per year. In 2014, the growth rate was 12.56 ppb. In 2015, the growth rate was 10.14 ppb. According to the WMO, methane's 2014–2015 absolute increase was 11 ppb.
(Also see above image #16: Methane's Rise since 2000)

Image #6.c is from:
Monthly CO₂ not under 400 ppm in 2016
http://arctic-news.blogspot.com/2016/11/monthly-co-not-under-400-ppm-in-2016.html




6.d1 Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide

“The science is clear. Without rapid cuts in CO₂ and other greenhouse gases, climate change will have increasingly destructive and irreversible impacts on life on Earth. The window of opportunity for action is almost closed,” said WMO Secretary-General Petteri Taalas.

“The last time the Earth experienced a comparable concentration of CO₂ was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now,” said Mr Taalas.

“CO₂ remains in the atmosphere for hundreds of years and in the oceans for even longer. There is currently no magic wand to remove all the excess CO₂ from the atmosphere,” said WMO Deputy Secretary-General Elena Manaenkova.

In the associated video, Dr Oksana Tarasova added that “changes in carbon dioxide levels that we are observing now do not happen naturally. Such changes never ever happened in the history of this Planet.”

As the image on the right shows, CH₄, CO₂ and N₂O levels in the atmosphere are, respectively, 257%, 146% and 122% their 1750 levels.

From:
As El Niño sets in, will global biodiversity collapse in 2019?

Also discussed at:
https://www.facebook.com/photo/?fbid=10161023341920161&set=a.10150592349770161



6.d2 Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide

Below is an updated version of above image, showing that CH₄, CO₂ and N₂O levels in the atmosphere in 2018 were, respectively, 259%, 147% and 123% of their pre-industrial (before 1750) levels.



Image #6.d is from:
Arctic Ocean November 2019
https://arctic-news.blogspot.com/2019/11/arctic-ocean-november-2019.html

Discussion at:
https://www.facebook.com/photo.php?fbid=10162579591910161




6.e Historic Methane Levels - CO₂ and CH₄ could cause a temperature rise of 18 Degrees Celsius

When looking only at carbon dioxide (CO₂) and methane (CH₄), how much temperature rise could they cause?


Above image shows methane in ppm CO₂e (carbon dioxide equivalent), using a Global Warming Potential (GWP) of 150. The image shows how carbon dioxide and methane could jointly cross 1200 ppm CO₂e in 2040. The image uses IPCC and WMO data up to 2018 to display three lines:
1. Black line: CO₂ in parts per million (ppm);
2. Red line: CH₄ in ppm CO₂e, using a GWP of 150;
3. Purple line: CO₂ and CH₄ in ppm CO₂e.
Trends are added, with a trend selected for methane to reflect a steep rise due to methane hydrate destabilization.

From: 
A Temperature Rise Of 18 Degrees Celsius
https://arctic-news.blogspot.com/p/a-temperature-rise-of-18-degrees-celsius.html



6.f Historic Methane Levels - CO₂ and CH₄ could cause a temperature rise of 18 Degrees Celsius

The image below illustrates that the joint impact of carbon dioxide and methane could cause the 1200 ppm CO₂e tipping point to be crossed in 2040. The image uses IPCC and WMO through 2019 to display three lines, with added trends:
- Black line: CO₂ in parts per million (ppm);
- Red line: CH₄ in ppm CO₂e, using a GWP of 150;
- Purple line: CO₂ and CH₄ in ppm CO₂e.

Trends for CH₄ are selected to reflect a steep rise as a result of methane hydrate destabilization.




6.g Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide

Below is an updated version of above image, showing that CH₄, CO₂ and N₂O levels in the atmosphere in 2018 were, respectively, 260%, 148% and 123% of their pre-industrial (before 1750) levels.



Above image illustrates the steep rise in methane, compared to carbon dioxide and nitrous oxide. Levels of carbon dioxide, methane and nitrous oxide reached new highs in 2019, reports the WMO. Carbon dioxide (CO₂) rose to 410.5 ppm (148% of its pre-industrial level), methane (CH₄) to 1877 ppb (260% of pre-industrial) and nitrous oxide (N₂O) to 332.0 ppb (123% of pre-industrial).

From:
There is no time to lose
https://arctic-news.blogspot.com/2020/11/there-is-no-time-to-lose.html

discussed at
https://www.facebook.com/photo/?fbid=10164574743410161&set=pcb.10164574764915161



6.h Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide


From the post:
Greenhouse gas levels keep rising at accelerating rates

discussion at: 
https://www.facebook.com/SamCarana/posts/10165455714030161




6.i Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide

[ click on images to enlarge ]
Methane levels are rising rapidly. The image to the right shows a trend that is based on NOAA 2006-2020 annual global mean methane data and that points at a mean of 3893 ppb getting crossed by the end of 2026.

Why is that value of 3893 ppb important? On April 8, 2021, carbon dioxide reached a peak of 421.36 ppm, i.e. 778.64 ppm away from the clouds tipping point at 1200 ppm, and 778.64 ppm CO₂e translates into 3893 ppb of methane at a 1-year GWP of 200.

In other words, a methane mean of 3893 ppb alone could cause the clouds tipping point to get crossed, resulting in an abrupt 8°C temperature rise.

Such a high mean by 2026 cannot be ruled out, given the rapid recent growth in mean annual methane levels (15.85 ppb in 2020, see inset on image).

Additionally, there are further warming elements than just carbon dioxide and methane, e.g. nitrous oxide and water vapor haven't yet been included in the CO₂e total.

Moreover, it may not even be necessary for the global mean methane level to reach 3893 ppb. A high methane peak in one single spot may suffice and a peak of 3893 ppb of methane could be reached soon, given that methane just reached a peak of 2862 ppb, while even higher peaks were reached over the past few years, including a peak of 3369 ppb recorded on the afternoon of August 31, 2018.

From the post
Overshoot or Omnicide?
discussed at:



6.k Historic Methane Levels - Historic rise of methane, carbon dioxide and nitrous oxide



The World Meteorological Organization (WMO) has released 2020 data for greenhouse gases. The atmospheric level of CO₂ was 413.2 parts per million (ppm) in 2020, 149% of the 1750 level. Methane (CH₄) was at 1889 parts per billion (ppb) in 2020, 262% of the 1750 level. Nitrous oxide (N₂O) was at 333.2 ppb, 123% of the 1750 level. 

“The last time the Earth experienced a comparable concentration of CO₂ was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now”, said WMO Secretary-General Prof. Petteri Taalas.

From:
Will COP26 in Glasgow deliver?
The Extinction page

Also discussed at:





7. Methane's Global Warming Potential (GWP) and Lifetime

7.a Methane's GWP (Global Warming Potential) or GHP (Global Heating Potential)

Measured over a few years, methane's global warming potential (GWP) is very high.

The image on the right, from IPCC AR5, shows that, over a 10-year timescale, the current global release of methane from all anthropogenic sources exceeds all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important than carbon dioxide emissions for driving the current rate of global warming.

And unlike carbon dioxide, methane's GWP does rise as more of it is released.

From the FAQ page:
Frequently Asked Questions
http://arctic-news.blogspot.com/p/faq.html

Also discussed at:
https://www.facebook.com/photo.php?fbid=10161971923480161





7.b Methane's GWP (Global Warming Potential) or GHP (Global Heating Potential), 2019

The values for methane's GWP that are used in above bar chart are also used in the graph below, showing that, over the first few years after release, methane has a GWP of more than 150 times that of carbon dioxide.

Above graph is based on low IPCC AR5 figures. The figures are low as they don't apply to fossil methane and don't include climate change feedbacks, while there also is additional warming due to the carbon dioxide that results from methane's oxidation. Moreover, research published in 2016 and 2018 concludes that methane is more potent than the IPCC described in AR5.

Image #7.b is from:
Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

Discussion at:
https://www.facebook.com/photo.php?fbid=10161971924340161




7.c Methane's GWP (Global Warming Potential) or GHP (Global Heating Potential), 2019

The top panels of the image below show figures used in IPCC AR5 (2013) for methane's lifetime and for methane's Global Warming Potential (GWP) over 10, 20 and 100 years.

IPCC AR5 gives methane a lifetime of 12.4 years. IPCC AR5 gives methane a GWP ranging from 84 to 87 for a 20-year horizon, and a GWP ranging from 28 to 36 for a 100-year horizon. The IPCC also depicts methane's GWP over 10 years. Methane is given a GWP over 10 years of 130, in line with a 2012 analysis by Sam Carana (image #7.d).


The other chart in above image shows that people's net emissions of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) from agriculture, forestry, and other land use were 23% of people's 2007-2016 emissions when using a Global Warming Potential (GWP) for methane of 28 (from IPCC special report Climate Change and Land), and they were 31% of people's 2007-2016 emissions when using a more appropriate GWP for methane of 150. 
 
Image #7.c is discussed at:
IPCC Report Climate Change and Land
https://arctic-news.blogspot.com/2019/08/ipcc-report-climate-change-and-land.html

Discussion at:
https://www.facebook.com/photo.php?fbid=10162138438410161





7.d Methane's GWP (Global Warming Potential) or GHP (Global Heating Potential), 2012

Methane's Global Warming Potential


A 2009 study by Shindell et al. points out that, when including direct and indirect effects, methane's GWP is 105 over 20 years.

The study also concludes that methane's GWP would likely be further increased when including ecosystem responses.

A short horizon is also most appropriate in the context of tipping points, such as accelerating methane releases from the seafloor of the Arctic Ocean.

Given the rapidity at which the biosphere is deteriorating, given the accelerating pace at which extreme weather events are striking the land all around the world, and given the grim prospects for people worldwide in the absence of rapid and radical change, it makes sense to focus on a short time horizon, i.e. as short as a few years, rather than decades.

In a 2012 analysis, Sam Carana shows that, based on figures by Shindell et al., methane's GWP is 130 times that of carbon dioxide over a period of 10 years.

In this image, the blue line is based on IPCC AR4 (2007) figures. The red line is based on figures from the study by Shindell et al.





Image #7.d from:
Methane hydrates
http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html



7.e Methane's GWP (Global Warming Potential) in AR6

IPCC AR6 gives methane a lifetime of 11.8 years and a GWP of 81.2 over 20 years and 27.9 over 100 years.

The image on the right shows trends based on IPCC AR6 GWP values pointing at a GWP for methane of 150 for a 9-year horizon and pointing at an even higher GWP for a shorter horizon. 

Such a short horizon is quite appropriate given the possibility of a high level for methane getting reached by 2026. Furthermore, a 9-year horizon is closer to methane's lifetime of 11.8 years. 

From:
Is the IPCC creating false perceptions, again?
and also discussed at:





8. Methane's Local Warming Potential (LWP) or Local Heating Potential (LHP)


Even more important than methane's high immediate GWP is methane's local warming potential (LWP), which includes the indirect effect of triggering further releases. In case of a large abrupt release, methane's lifetime will be extended, due to hydroxyl depletion. Much of the methane can be expected to persist locally for decades, at its highest LWP, since there's very little hydroxyl in the atmosphere above the Arctic in the first place, so very little methane will get oxidized there. The impact of such an abrupt release will be felt most strongly in the Arctic, where the release took place. Since it will take time for methane to spread away from the Arctic, much of the entire release will remain concentrated above the Arctic.

The additional warming that this will cause in the Arctic will make the sea ice decline even more dramatically than is already the case now. The combined LWP of snow cover loss, sea ice loss and methane releases in the Arctic is huge. This is bound to trigger further releases of methane in the Arctic, and their joint impact will accumulate, as illustrated in the next image.

Image #8. from:
Methane hydrates
http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html



9. The Threat of Runaway Global Warming

9.a The Threat of Runaway Global Warming (Methane Releases)

Even small releases of methane from the seafloor of the Arctic Ocean are very dangerous; their explosive eruption from the seafloor and their huge local warming impact threatens to further destabilize sediments under the Arctic Ocean and trigger further methane releases.


Image #9.a from:
High methane levels over the Arctic Ocean on January 14, 2014
http://arctic-news.blogspot.com/2014/01/high-methane-levels-over-the-arctic-ocean-on-january-14-2014.html

and also used at the page:
How much time is there left to act?
https://arctic-news.blogspot.com/p/how-much-time-is-there-left-to-act.html



9.b The Threat of Runaway Global Warming (Temperature Rise and Deaths)

With continued warming of the Arctic Ocean, heat increasingly threatens to reach the seafloor of the Arctic Ocean and unleash huge methane eruptions from destabilizing clathrates. The threat is that runaway warming will strike first in the Arctic, to spread from there, causing heatwaves and firestorms across North America and Siberia, while adding massive amounts more methane, soot and carbon dioxide to the atmosphere globally, as forests, peat bogs and tundras at higher latitudes burn, with the threat of escalating into runaway global warming, causing huge temperature swings and extreme weather events, and contributing to increasing depletion of fresh water and food supply.


Image #9.b from:
How many death could result from failure to act on climate change?
http://arctic-news.blogspot.com/2014/05/how-many-deaths-could-result-from-failure-to-act-on-climate-change.html



10. Methane's Rise

10.a Methane's Rise (1984 - 2015)

This image shows the rise of methane levels from 1984, created with World Meteorological Organization (WMO) data up to 2014. The square marks a high mean 2015 level, from NOAA's MetOp-2 satellite images, and it is added for comparison, so it does not influence the trendline, yet it does illustrate the direction of rise of methane levels and the threat that global mean methane levels will double well before the year 2040.


Image #10.a from:
Ocean Heat
https://arctic-news.blogspot.com/2015/11/ocean-heat.html



10.b Methane's Rise (2000 - 2015)

Growth in methane levels has been accelerating recently. Contained in existing data is a trend indicating that methane levels could increase by a third by 2030 and could almost double by 2040. Unlike carbon dioxide, methane's GWP does rise as more of it is released. Methane's lifetime can be extended to decades, in particular due to depletion of hydroxyl in the atmosphere.


Image #10.b from:
Less sea ice, warmer Arctic Ocean
https://arctic-news.blogspot.com/2016/11/less-sea-ice-warmer-arctic-ocean.html




10.c Methane's Rise (2009 - 2022)


The image on the right shows NOAA globally averaged marine surface monthly means up to the most recent one which is April 2021. The NOAA annual mean methane data are:
in 2015: 1834 ppb
in 2016: 1843 ppb
in 2017: 1850 ppb
in 2018: 1857 ppb
in 2019: 1866 ppb (most recent IPCC level)
in 2020: 1879 ppb

Note also that above NOAA data are for global mean marine surface readings. At higher altitudes, even higher levels show up.

From:
Is the IPCC creating false perceptions, again?
and also discussed at:
and at:
https://www.facebook.com/SamCarana/posts/10165774744980161



11. Methane levels are rising most strongly over Arctic (maps 2009 - 2013)


Image #11 from:
Dramatic increase in methane in the Arctic in January 2013
http://arctic-news.blogspot.com/2013/02/dramatic-increase-in-methane-in-the-arctic-in-january-2013.html



12. Methane rise at higher altitudes

12.a Methane rise at higher altitudes (April 22 version)

The image below compares mean methane levels on the morning of April 22 between the years 2013 to 2017, confirming that methane levels are rising most strongly at higher altitudes, say between 6 to 17 km (which is where the Troposphere ends at the Equator), as compared to altitudes closer to sea level. This strong rise at higher altitudes may not be as noticeable when taking samples from ground stations. This was discussed in earlier posts such as in this post, in this post and in this post.


The table below shows the altitude equivalents in feet (ft), meter (m) and millibar (mb).
57,016 ft44,690 ft36,850 ft30,570 ft25,544 ft19,820 ft14,385 ft 8,368 ft1,916 ft
17,378 m13,621 m11,232 m 9,318 m 7,786 m 6,041 m 4,384 m 2,551 m 584 m
 74 mb 147 mb 218 mb 293 mb 367 mb 469 mb 586 mb 742 mb 945 mb

Above image compares mean methane levels on the morning of April 22 between the years 2013 to 2017, confirming that methane levels are rising most strongly at higher altitudes, say between 6 to 17 km (which is where the Troposphere ends at the Equator), as compared to altitudes closer to sea level. This was discussed in earlier posts such as this one.

From the post
10°C or 18°F warmer by 2021?



12.b Methane rise at higher altitudes (numerous altitudes)

The image below shows that on September 14, 2016, methane levels at 367 mb were as high as 2697 ppb and global mean methane level was as high as 1865 ppb.


Image #12.b from:
Arctic Sea Ice September 2016 - Update
http://arctic-news.blogspot.com/2016/09/arctic-sea-ice-september-2016-update.html



12.c Methane rise at higher altitudes (numerous altitudes)

The image below shows that on September 30, 2019, pm, the MetOp-1 satellite recorded mean methane levels at 293 mb as high as 1914 ppb.


Image #12.c from:

Could Humans Go Extinct Within Years?https://arctic-news.blogspot.com/2020/01/could-humans-go-extinct-within-years.html



12.d Methane reaching the Stratosphere


The MetOp satellites typically record the highest annual mean methane level in September. The image below, from an earlier post, shows that on the afternoon of September 30, 2019, the MetOp-1 satellite recorded the highest mean methane level, i.e. 1914 parts per billion, at 293 mb.


Above image shows that methane levels have risen most at higher altitude over the years. As discussed in an earlier post, methane eruptions from the Arctic Ocean can be missed by measuring stations that are located on land and that often take measurements at low altitude, thus missing the methane that rises in plumes from the Arctic Ocean. Since seafloor methane is rising in plumes, it hardly shows up on satellite images at lower altitude either, as the methane is very concentrated inside the area of the plume, while little or no increase in methane levels is taking place outside the plume. Since the plume will cover less than half the area of one pixel, such a plume doesn't show up well at low altitudes on satellite images.

Over the poles, the Troposphere doesn't reach the heights it does over the tropics. At higher altitudes, methane will follow the Tropopause, i.e. the methane will rise in altitude while moving closer to the Equator.

Methane rises from the Arctic Ocean concentrated in plumes, pushing away the aerosols and gases that slow down the rise of methane elsewhere, which enables methane erupting from the Arctic Ocean to rise straight up fast and reach the stratosphere.

The rise of methane at these high altitudes is very worrying. Once methane reaches the stratosphere, it can remain there for a long time. The IPCC in 2013 (AR5) gave methane a lifetime of 12.4 years. The IPCC in 2001 (TAR) gave stratospheric methane a lifetime of 120 years, adding that less than 7% of methane did reach the stratosphere.

From: 
2020 Siberian Heatwave continues
2020 Siberian Heatwave continues



12.e The signature of seafloor methane

Above image shows that, over the years, methane levels have risen strongly high in the Troposphere, up into the Stratosphere. This looks like the signature of methane that originated from the seafloor of the Arctic Ocean. The image below further explains why.


The Tropopause separates the Troposphere from the Stratosphere. The Troposphere ends at a height of some 9 km (5.6 mi; 30,000 ft) at the poles, and at a height of some 17 km (11 mi; 56,000 ft) at the Equator.

As said, methane is erupting from the seafloor of the Arctic Ocean concentrated in plumes, unlike methane from wetlands and agriculture that is typically emitted over a wide area. Since seafloor methane is rising in plumes, it hardly shows up on satellite images at lower altitude either, as the methane is very concentrated inside the area of the plume, while little or no increase in methane levels is taking place outside the plume. Since the plume will cover less than half the area of one pixel, such a plume doesn't show up well at low altitudes on satellite images,

Methane over the Arctic typically does show up on satellite images at altitudes between 4.4 km and 6 km (14,400 ft and 19,800 ft). Seafloor methane will show up better at these higher altitudes where it spreads out over larger areas. At even higher altitudes, methane will then follow the Tropopause, i.e. the methane will rise in altitude while moving closer to the Equator.

NOAA image

In conclusion, methane originating from the seafloor of the Arctic Ocean can strongly contribute to high methane levels that show up over the Equator at higher altitudes, but this methane can be misinterpreted for methane originating from tropical wetlands.

From the post:
Methane Erupting From Arctic Ocean Seafloor
http://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

Discussion at:
https://www.facebook.com/SamCarana/posts/10158217636375161




12.f The signature of seafloor methane

Even relatively small methane releases could cause tremendous heating, if they reach the stratosphere. Methane rises from the Arctic Ocean concentrated in plumes, pushing away the aerosols and gases that slow down the rise of methane elsewhere, which enables methane erupting from the Arctic Ocean to rise straight up fast and reach the stratosphere. IPCC AR6 gives methane a lifetime of 11.8 years. IPCC TAR gave stratospheric methane a lifetime of 120 years, adding that less than 7% of methane did reach the stratosphere at the time.


The MetOp-1 satellite recorded a mean global methane level of 1956 ppb on September 11, 2021 am, at 293 mb. This corresponds with an altitude of some 9 km, which is where the Stratosphere starts at the North Pole. The conversion table shows that the Tropopause, which separates the Troposphere from the Stratosphere, is lower over the North Pole (at about 9 km altitude) than over the Equator (17 km altitude).


From:
Is the IPCC creating false perceptions, again?
and also discussed at:

The Tropopause part of above image was earlier posted at:
There is no time to lose


13. Cartoons

13.a and 13.b Arctic Methane Monster Cartoons


People seem to want it  -  IPCC keeps downplaying Arctic methane threat

 Images #13.a and #13.b from:

Arctic Methane Monster
https://arctic-news.blogspot.com/2013/09/arctic-methane-monster.html



13.c Do NOT tell them the monster exists!

Do NOT tell them the monster exists
Image #13.c from:
Just do NOT tell them the monster exists
https://arctic-news.blogspot.com/2013/10/just-do-not-tell-them-the-monster-exists.html




13.d Attaboy (August 2019)

[ click on image to enlarge ]
Image #13.d from:
IPCC Report Climate Change and Land
https://arctic-news.blogspot.com/2019/08/ipcc-report-climate-change-and-land.html




13.e Attaboy (August 2019)

The threat of large methane eruptions from the seafloor of the Arctic Ocean and how the IPCC chooses to inform people about this threat.

Image #13.e from:
IPCC Report Ocean and Cryosphere in a Changing Climate
https://arctic-news.blogspot.com/2019/09/ipcc-report-ocean-and-cryosphere-in-a-changing-climate.html

discussion at:
https://www.facebook.com/SamCarana/posts/10162278151670161



13.f Attaboy (July 2020)

As temperatures keep rising, should the IPCC raise the alarm?


Some 1,750 jurisdictions in 30 countries have now declared a climate emergency, according to this post dated July 8, 2020. The United Nations does acknowledge the Climate Emergency, but its description is sourced from the IPCC Global Warming of 1.5°C report that was approved back in 2018. A lot has happened since, as described in many posts at Arctic-news. When a state of emergency is declared, doesn't one expect such a declaration to result in action, complete with updates on the effectiveness of the action?

Image #13.f from:
Arctic Sea Ice at Record Low for Time of Year
https://arctic-news.blogspot.com/2020/07/arctic-sea-ice-at-record-low-for-time-of-year.html



14. The buffer has gone

The danger is that, as Arctic sea ice continues to decline, more heat will reach the seafloor and will destabilize methane hydrates contained in sediments at the bottom of the Arctic Ocean, resulting in huge methane eruptions.

The Buffer has gone, feedback #14 on the Feedbacks page

Image #14 from:
September 2015 Sea Surface Warmest On Record



15.a Ominous warnings (high peak methane levels)

Ominously, methane levels as high as 2961 parts per billion were recorded by the MetOp-2 satellite on October 24, 2019, in the afternoon at 469 mb.


Image #15.a from the post:
Arctic Ocean October 2019
https://arctic-news.blogspot.com/2019/10/arctic-ocean-october-2019.html

Discussion at:
https://www.facebook.com/photo.php?fbid=10162424171555161



15.b Ominous warnings (high mean methane levels)

 Ominously, the MetOp-1 satellite recorded a mean global methane level of 1914 parts per billion, on September 30, 2019, pm at 293 mb.


Image #15.b from the post:
IPCC Report Ocean and Cryosphere in a Changing Climate
https://arctic-news.blogspot.com/2019/09/ipcc-report-ocean-and-cryosphere-in-a-changing-climate.html

Discussion at:
https://www.facebook.com/photo.php?fbid=10162300982735161



15.c Ominous warnings (high mean methane levels)

The MetOp-1 sattelite recorded a mean methane level of 1917 ppb at 293 mb on August 4, 2020 pm, with high methane levels visible over the East Siberian Arctic Shelf (ESAS).


From the post:
North Hole 2020?
https://arctic-news.blogspot.com/2020/08/north-hole-2020.html



16.a Methane rising from Arctic Ocean seafloor

This image below shows high methane levels over the Arctic at surface level. The image was made with a screenshot of a forecast for Friday 16 Jan 2023, 03 UTC, run on Friday 16 Jan 2023, 00 UTC. The scale at surface level goes from 0 parts per billion (ppb) up to 10,000 ppb. The dark red goes from 2160 ppb to 10,000 ppb.




16.b Methane rising from Arctic Ocean seafloor

The image below was made with a screenshot of methane at 850 hectopascal (pressure level in hPa, i.e. the same as 850 millibar or mb), which is a bit higher in altitude than surface level. The image was made with a screenshot of a forecast for Friday 16 Jan 2023, 03 UTC, run on Friday 16 Jan 2023, 00 UTC. The scale for 850 hPa goes from 1420 ppb to 24,840 ppb. The dark red goes from 2020 ppb to 24,840 ppb. 




16.c Methane rising from Arctic Ocean seafloor

The image below was made with a screenshot of methane at 500 hPa, which is again higher in altitude. The image was made with a screenshot of a forecast for Friday 16 Jan 2023, 03 UTC, run on Friday 16 Jan 2023, 00 UTC. The scale for 500 hPa goes from 1620 ppb to 2360 ppb. The red color goes from 1950 ppb to 2360 ppb. 




16.d Methane rising from Arctic Ocean seafloor

The image below was made with a screenshot of methane at 300 hPa, which is again higher in altitude. The image was made with a screenshot of a forecast for Friday 16 Jan 2023, 03 UTC, run on Friday 16 Jan 2023, 00 UTC. The scale goes up to 2300 ppb, the black and purple go from 1560 ppb to 1740 ppb. The green colors start at 1800 ppb. The dark red goes from 1940 ppb to 2300 ppb. 


For the Arctic, the altitude that corresponds with 300 hPa is at the upper edge of the troposphere. The tropopause, i.e. the border between the troposphere and the stratosphere, is lower in altitude over the Arctic (at about 300 hPa, corresponding to about 9,000 km in altitude) than over the Equator (where the tropopause is at about 80 hPa, corresponding to about 17,000 km in altitude), reason why methane rises and accumulates over the Arctic at about 300 hPa, before moving to higher altitudes closer to the Equator just below the tropopause. Because of this accumulation of methane at about 300 hPa over the Arctic, this is the altitude where methane is typically at its highest global average level.

The troposphere has been expanding upward, due to global warming. A 2021 analysis concludes that from 1980 to 2020, the height of the tropopause on the Northern Hemisphere has increased at about 50 to 60 m per decade. 

The above Copernicus forecasts for Jan.16, 2023, 03 UTC, with methane at surface level and at 850 hPa, 500 hPa and 300 hPa, are discussed at: 

Copernicus forecasts for additional days (for Jan.11, 2023, and for Jan.13, 2023, in comments) are also discussed at:



16.e Methane rising from Arctic Ocean seafloor

The animation below is made with images recorded by the Metop-B satellite on Jan.6, 2023 PM, showing methane at the highest end of the scale (magenta color) first (at low altitude) becoming visible predominantly over oceans and at higher latitudes North, and then gradually becoming also visible more spread out over the globe at higher altitude, while reaching its highest mean (of 1925 ppb) and peak (of 2708 ppb) at 399 mb.

 
This indicates that significant amounts of methane are rising up from the Arctic Ocean. 

From the post

1 comment:

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