Showing posts sorted by relevance for query high methane levels over. Sort by date Show all posts
Showing posts sorted by relevance for query high methane levels over. Sort by date Show all posts

Wednesday, November 25, 2020

There is no time to lose

Carbon dioxide levels continue at record levels, despite COVID-19 lockdown, the WMO reports. The increase in carbon dioxide from 2018 to 2019 was larger than that observed from 2017 to 2018 and larger than the average annual growth rate over the last decade.

The rise has continued in 2020. The lockdown did cut emissions of many pollutants and greenhouse gases, but any impact on carbon dioxide levels - the result of cumulative past and current emissions - is in fact no bigger than the normal year to year fluctuations. 

“Carbon dioxide remains in the atmosphere for centuries and in the ocean for even longer. 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. But there weren’t 7.7 billion inhabitants,” said WMO Secretary-General Professor Petteri Taalas.

“The COVID-19 pandemic is not a solution for climate change. However, it does provide us with a platform for more sustained and ambitious climate action to reduce emissions to net zero through a complete transformation of our industrial, energy and transport systems. The needed changes are economically affordable and technically possible and would affect our everyday life only marginally. It is to be welcomed that a growing number of countries and companies have committed themselves to carbon neutrality,” he said. “There is no time to lose.”


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).

So, given that there's no time to lose, why mention carbon neutrality, and not 100% clean, renewable energy? Also, let's not lose sight of other emissions such as N₂O. Yes, dramatic cuts in CO₂ emissions do need to happen rapidly, and yes, this does require a complete transformation of industry, energy and transport. Nonetheless, N₂O emissions are also important and most N₂O emissions result from land use, such as food production and waste handling, which must also change. 

[ from earlier post ]
The IPCC (AR5) gave N₂O a lifetime of 121 years and a 100-year global warming potential (GWP) of 265 times that of carbon dioxide. Furthermore, N₂O also causes stratospheric ozone depletion. 

The IPCC, in special report Climate Change and Land, found that agriculture, forestry and other land use activities accounted for some 13% of CO₂, 44% of CH₄, and 82% of N₂O emissions from human activities globally during 2007-2016, representing 23% of total net anthropogenic emissions of greenhouse gases.

If emissions associated with pre- and post-production activities in the global food system are included, the emissions could be another 14% higher, i.e. as high as 37% of total net anthropogenic greenhouse gas emissions, the IPCC added.

Let's get back to that 23%. The IPCC calculates this 23% by using a GWP of 28 for CH₄. Over the first few years, however, the GWP of CH₄ is more than 150, as discussed in an earlier post. When using a GWP of 150, land use emissions rise from 23% to 31%, as the image on the right shows. Add another 14% from further food-related emissions and the total share for land use becomes 45% of people's emissions. 

In other words, all polluting emissions need to be reduced. Moreover, a recent paper by Jorgen Randers et al. points out that, even if all greenhouse gas emissions by people would stop immediately, and even if CO₂ levels in the atmosphere would revert back to pre-industrial levels, overall temperatures would still keep rising for centuries to come. Another recent paper, by Tapio Schneider et al., points out that solar geoengineering may not prevent strong warming from direct effects of CO2 on stratocumulus cloud cover. 

This means that the threat is even more menacing when including large methane releases that threaten to occur as temperatures keep rising in the Arctic and sediments at the seafloor of the Arctic Ocean threaten to get destabilized, resulting in the eruption of huge amounts of methane. 

What is the joint impact of carbon dioxide and methane? The WMO reported CO₂ levels of 410.5 ppm and CH₄ levels of 1877 ppb in 2019. As discussed in an earlier post, over the first few years after release, methane's GWP is more than 150 times higher than carbon dioxide. Accordingly, the 2019 level of 1877 ppb of methane translates into global heating of 281.55 ppm CO₂e. Together, that makes 692.5 ppm CO₂e, which is 507.5 ppm CO₂e away from the 1200 ppm CO₂e cloud tipping point

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. 

How could such a steep rise in methane levels occur?

Stronger methane releases from subsea permafrost can be expected, says a paper by Natalia Shakhova et al. A 1000-fold methane increase could occur, resulting in a rise of as much as 6°C within 80 years, with more to follow after that, according to a paper by Atsushi Obata et al.

Seafloor methane releases could be triggered by strong winds causing an influx of warm, salty water into the Arctic ocean (see this earlier post and this page). 

Since little hydroxyl is present in the atmosphere over the Arctic, it is much harder for this methane to get broken down.

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. 

The IPCC (AR5) gave methane a lifetime of 12.4 years. The 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 images on the right illustrate this. On November 20 pm, 2020, the MetOp-1 satellite recorded high methane levels over the Arctic Ocean at 293 mb (top image on the right). This corresponds with an altitude of some 9 km altitude, which is where the Stratosphere starts at the North Pole. The global mean methane level at that altitude was 1921 ppb.

The next images show areas with high levels of methane, as indicated by the magenta color, remaining present over the Arctic Ocean even at higher altitudes.

The higher the altitude, the more methane will concentrate over the Equator. Yet at 229 mb, high methane levels are still visible north of Siberia, while global mean methane levels were still very high, i.e. 1916 ppb. 

Even at 156 mb, there still are high methane levels visible (green circle, third image right). 

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). 

The fifth image on the right, from an earlier post, shows that methane has accumulated more at higher altitudes over the years. 

The sixth image on the right shows that the MetOp-1 satellite recorded mean methane levels of 1925 ppb at 293 mb on December 2, 2020 am, with high methane levels present over the Arctic Ocean.

The next image shows that a peak methane level of 2715 ppb was recorded by the SNPP satellite on November 30, 2020 pm at 399.1 mb.

The animation on the right shows high methane levels recorded by the MetOp-2 satellite on December 2, 2020 pm, at a number of altitudes: 

- At 1000 mb (close to ground/sea level) a peak methane level of 2129 ppb shows up north of Svalbard. 

- At 918 mb, methane peaks at 2408 ppb and high methane levels show up over the Artic Ocean.

- At 815 mb, methane reaches a peak of 2582 ppb and high methane levels are visible over larger parts of the Arctic Ocean. 

- At 742 mb, methane reaches a peak of 2663 ppb and high methane levels are visible over even larger parts of the Arctic Ocean. 

- At 586 mb, methane reaches a peak of 2518 ppb and high methane levels are visible over a huge part of the Arctic Ocean, while hardly any high levels of methane are visible over land. 

- At 293 mb, methane reaches a peak of 2411 ppb and high levels of methane are still visible over the Arctic Ocean, even at this high altitude. 

[ from earlier post ]
In conclusion, a huge temperature rise could occur soon, even with a relatively small increase in carbon dioxide and methane releases. 

As above image illustrates, a temperature rise of more than as 10°C could eventuate as soon as 2026 when taking into account aerosol changes, albedo changes, water vapor, nitrous oxide, etc., as an earlier analysis shows. 

The joint impact of these warming elements threatens the cloud tipping point to be crossed and the resulting 8°C rise would then come on top of the 10°C rise, resulting in a total rise of 18°C, as illustrated by the image on the right, from an earlier post.

Indeed, there is no time to lose. It is high time to stop the denial of the size of the threats and challenges that the world faces, the harm inflicted and the speed at which developments could strike. 

The situation is dire and calls for immediate, comprehensive and effective action, as described in the Climate Plan


• WMO Greenhouse GasBulletin
https://public.wmo.int/en/resources/library/wmo-greenhouse-gas-bulletin

• WMO news release: Carbon dioxide levels continue at record levels, despite COVID-19 lockdown
https://public.wmo.int/en/media/press-release/carbon-dioxide-levels-continue-record-levels-despite-covid-19-lockdown

• Understanding the Permafrost–Hydrate System and Associated Methane Releases in the East Siberian Arctic Shelf, by Natalia Shakhova, Igor Semiletov and Evgeny Chuvilin (2019)
https://www.mdpi.com/2076-3263/9/6/251

• Damage of Land Biosphere due to Intense Warming by 1000-Fold Rapid Increase in Atmospheric Methane: Estimation with a Climate–Carbon Cycle Model - by Atsushi Obata et al. (2012) 
https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-11-00533.1

• Possible climate transitions from breakup of stratocumulus decks under greenhouse warming, by Tapio Schneider et al. (2019)
https://www.nature.com/articles/s41561-019-0310-1

• Solar geoengineering may not prevent strong warming from direct effects of CO2 on stratocumulus cloud cover - by Tapio Schneider et al. 
https://www.pnas.org/content/early/2020/11/10/2003730117

• An earth system model shows self-sustained melting of permafrost even if all man-made GHG emissions stop in 2020 - by Jorgen Randers et al.
https://www.nature.com/articles/s41598-020-75481-z

Thursday, January 16, 2014

High methane levels over the Arctic Ocean on January 14, 2014

[ click on image to enlarge - note that 'level' is the peak reading for the respective altitude ]
Above image shows IASI methane levels on January 14, 2014, when levels as high as 2329 ppb were recorded. This raises a number of questions. Did these high methane levels originate from releases from the Arctic Ocean, and if so, how could such high methane releases occur from the seafloor of the Arctic Ocean at this time of year, when temperatures in the northern hemisphere are falling?

Location

Let's first establish where the methane releases occurred that caused these high levels. After all, high methane concentrations are visible at a number of areas, most prominently at three areas, i.e. at the center of the Arctic Ocean, in Baffin Bay and over an area in Asia stretching out from the Taklamakan Desert to the Gobi Desert.

Closer examination, illustrated by the inset, shows that the highest methane levels were recorded in the afternoon, and at altitudes where methane concentrations over these Asian deserts and over Baffin Bay were less prominent, leading to the conclusion that these high methane levels did indeed originate from the seafloor of the Arctic Ocean.

The image below, showing 1950+ ppb readings over the past few days, illustrates the magnitude of the methane concentrations over the Arctic Ocean.


High concentrations persist over the Arctic Ocean

High methane concentrations have persistently shown up over the Arctic Ocean from October 1, 2013, through to January 2014. On January 19, 2014, levels as high as 2363 ppb were recorded over the Arctic Ocean, as illustrated by the image below.

[ click on image to enlarge ]
Causes

What caused these high releases from the seafloor of the Arctic Ocean to persist for so long? At this time of year, one may have thought that the water in the Arctic Ocean would be much colder than it was, say, on October 1, 2013.

Actually, as the combination image below shows, sea surface temperatures have not decreased much at the center of the Arctic Ocean between early October, 2013 (left) and January 14, 2014 (right). In the area where these high methane concentrations occured, sea surface temperatures have remained the same, at about zero degrees Celsius.

[ click on image to enlarge ]
Furthermore, as the above image shows, surface temperatures in the Atlantic Ocean may have fallen dramatically with the change of season, but temperatures in the Arctic Ocean have changed only little.

In this case of course, what matters more than surface temperatures are water temperatures at greater depth. Yet, even here temperatures in the Arctic Ocean will have decreased only slightly since early October 2013, as the Gulf Stream has continued to push warmer water into the Arctic, i.e. water warmer than the water in the Arctic Ocean. In other words, the heating impact of the Gulf Stream has continued.

Furthermore, as the sea ice extent increased, there have been less opportunities for the heat to evaporate on the surface and for heat to be transferred from the Arctic Ocean to the air.

Finally, what matters a lot is salinity. The combination image below compares salinity levels between October 1, 2013 (left), and January 14, 2014 (right).

[ click on image to enlarge ]
Salinity levels were low on October 1, 2013, as a lot of ice and snow had melted in the northern summer and rivers had carried a lot of fresh water into the Arctic Ocean. After October 1, 2013, little or no melting took place, yet the Gulf Stream continued to carry waters with higher salt levels from the Atlantic Ocean into the Arctic Ocean.

Annual mean sea surface salinity
Seawater typically has a salinity level of over 3%; it freezes and melts at about −2°C (28°F). Where more saline water from the Atlantic Ocean flows into the Arctic Ocean, the water in the Arctic Ocean becomes more saline. The freezing and melting point of fresh water (i.e. zero salinity) is 0°C (or 32°F). More salinity makes frozen water more prone to melting, i.e. at temperatures lower than 0°C, or as low as −2°C.

As the salinity levels of the water on the seafloor of the Arctic Ocean increased, the ice that had until then held the methane captive in hydrates on the seafloor of the Arctic Ocean started to melt. Indeed, the areas in the Arctic Ocean where the high methane releases occurred on January 14, 2014 (top image) show several practical salinity units (psu) increase since October 1, 2013.

Higher salinity levels are now reaching the faultline that runs through the Arctic Ocean from the top of Greenland to the Laptev Sea, where major releases are taking place now, as illustrated by the image below, with faultlines added on the insets.

[ click on image to enlarge ]
Above image shows methane levels recorded on the evening of January 16, 2014 (main image). The top left inset shows all methane readings of 1950 ppb and higher on January 15 and 16, 2014, while the bottom left inset shows methane readings of 1950 ppb and higher on January 16, 2014, p.m. only and for seven layers only (from 469 to 586 mb), when levels as high as 2353 ppb were reached (at 469 mb).

Quantities

These high levels of methane showing up over the Arctic Ocean constitute only part of the methane that did escape from the seafloor of the Arctic Ocean. Where these high concentrations did show up, the ocean can be thousands of meters deep, giving microbes plenty of opportunity to decompose methane rising through the water first. Furthermore, the methane has to pass through sea ice that is now getting more than one meter thick in the area where these high levels of methane showed up on satellite records. In conclusion, the quantities of methane that were actually released from the seafloor must have been huge.

Importantly, these are not one-off releases, such as could be the case when hydrates get destabilized by an earthquake. As the Arctic-news blog has documented, high releases from the seafloor of the Arctic Ocean have been showing up persistently since early October 2013, i.e. three months ago. This blog has warned about the threat for years. This blog has also described in detail the mechanisms that are causing these releases and the unfolding climate catastrophe that looks set to become more devastating every year.

Given that a study submitted in April 2013 concluded that 17 Tg annually was escaping from the East Siberian Arctic Shelf alone, given the vast quantity of the releases from hydrates that show up on IASI readings and given the prolonged periods over which releases from hydrates can persist, I put the methane being released from hydrates under the seafloor of the Arctic Ocean in the highest category, rivaling global emissions from fossil fuel, from agriculture and from wetlands. As said, 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.



This is vastly more than the IPCC's most recent estimates, which put emissions from hydrates and permafrost at 7 Tg annually, a mere 1% of the total annual methane emissions globally, as illustrated by the image below.


Impacts and Response

Huge releases from the seafloor of the Arctic Ocean have occurred persistently since early October 2013, even when releases like this may show up for one day in one area without showing up in that same area the next day on satellite images.

This apparent 'disappearance' can be due to the Coriolis effect that appears to move the methane, whereas it is in fact the Earth that is spinning underneath the methane. This doesn't mean that the methane had disappeared. Actually, much of this methane will persist over the Arctic for many years to come and will continue to exercize its very high initial warming potential over the Arctic for years.

Furthermore, even if less methane may show up on satellite images the next day, that doesn't necessarily mean that releases from the seafloor has stopped. Instead, it looks like methane is being released continuously from destabilizing hydrates. The methane may accumulate underneath the sea ice for some time, to burst through at a moment when fractures or ruptures occur in the sea ice, due to changes in wind and wave height.


The threat here is that methane will further warm up the air over the Arctic, causing further weakening of the Jet Stream and further extreme weather events, particularly extreme warming of water all the way along the path of the Gulf Stream from the Atlantic Ocean into the Arctic Ocean, in turn triggering further releases from hydrates at the seafloor of the Arctic Ocean and escalating into runaway global warming. This threat calls for comprehensive and effective action, such as described at the ClimatePlan blog.





Wednesday, January 8, 2014

High Methane Levels over Arctic Ocean continue in 2014

The high methane levels over the Arctic Ocean, the biggest story of 2013, continue in 2014, as illustrated by the image below.


As above image shows, high methane readings (as high as 2301 ppb on January 6, 2014) continue in 2014. High methane concentrations continue to enter the atmosphere where the sea ice is thin and where the sea ice is carried by currents outside of the Arctic Ocean.

The inset shows ice thickness on January 6, 2014. The inset highlights the huge amounts of sea ice that are carried by the sea current from the north of Greenland into the Atlantic Ocean.

What is the impact of these high methane releases over the Arctic Ocean on global methane levels? The image below shows the most recent global methane levels available from NOAA.


The image below shows readings from surface flask at Mauno Loa, Hawaii, with two recent readings (in the top right corner) reaching levels close to 1880 ppb.


Clearly, methane levels are rising globally and high releases over the Arctic Ocean are contributing to the global rise. The images below show recent data from stations in the Arctic, i.e. the image below showing readings from in situ measurements at the station at Barrow, Alaska, and the image further below showing flask samples taken at Tiksi, Russia.



Note that the above images reflect land-based measurements taken at altitudes that are typically too low to capture the extent at which methane is rising in the atmosphere over the Arctic Ocean. Nonetheless, the wind can at times carry along some of the methane from the Arctic Ocean, as is apparent in a number of readings in above images showing levels of over 2100 ppb.

The image below shows high methane releases over the Arctic Ocean, as recorded on (part of) January 7, 2014, when levels were reached as high as 2381 ppb.


The image below shows methane levels on (part of) January 8, 2014, when levels as high as 2341 ppb were recorded. The inset confirms indications that these high levels originate from the Arctic Ocean.


These high methane concentrations over the Arctic are contributing to high temperature anomalies that further accelerate warming in the Arctic, as illustrated by the image below.


For a more detailed description of the kinds of warming and feedbacks that are hitting the Arctic, see the post The Biggest Story of 2013.



Tuesday, November 5, 2013

Methane, Faults and Sea Ice

Shield breaking down

Until now, Arctic sea ice has been acting as a shield, in a number of ways, including:
  • preventing sunlight from warming up water underneath the sea ice 
  • facilitating currents that currently cool the bottom of the sea
  • preventing much methane from entering the atmosphere; as discussed in an earlier post, the sea ice collects and holds the methane in places close enough to the surface for the methane to be consumed through photochemical and biochemical oxidation. 
However, as the sea ice declines, this shield is breaking down. As a result:
  • more sunlight is reaching the water, contributing to warming of water in the Arctic Ocean
  • sea ice decline comes with the danger of weakened currents that cool the seabed
  • more methane is able to penetrate the cracks and openings in the ever-thinner ice. 
Warm Water traveling along Gulf Stream

At the same time, global warming is causing more extreme weather events to occur, such as the record warmth observed in July 2013 in part of the northeastern Atlantic Ocean off the coast of North America. As discussed in a recent post, this warm water has meanwhile traveled along the Gulf Stream and reached the Arctic Ocean.

Methane venting from Seabed

As a result, warmer water is now destabilizing sediments under the seabed that hold huge amounts of methane in the form of free gas and hydrates. Methane is now venting from the seabed of the Arctic Ocean, driven by sea ice decline and "by Gulf Stream heating, earthquakes and deep pyroclastic eruptions", as Malcolm Light explains in a recent comment and as described in an earlier post.

The image below shows the result: Massive amounts of methane venting from the seabed, penetrating the sea ice, and entering the atmosphere over the Arctic Ocean. 


Methane, Faults and Sea Ice

The animation below illustrates links between: 
  • The fault line that crosses the Arctic Ocean and forms the boundery between two tectonic plates (i.e. the North American Plate and the Eurasian Plate)
  • Arctic sea ice, which until now has acted as a shield
  • The prominence of high methane readings over the Arctic Ocean 

Monday, March 13, 2017

Methane Erupting From Arctic Ocean Seafloor

Seafloor methane often missed in measurements

Large amounts of methane are erupting from the seafloor of the Arctic Ocean. These methane eruptions are often missed by measuring stations, because these stations are located on land, while measurements are typically taken at low altitude, thus missing the methane that rises in plumes from the Arctic Ocean. By the time the methane reaches the coast, it has typically risen to higher altitudes, thus not showing up in low-altitude measurements taken at stations on land.

The image below shows the highest mean global methane levels on March 10 over the years from 2013 through 2017, for selected altitudes corresponding to 945 mb (close to sea level) to 74 mb.


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

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.

Methane levels as high as 2846 ppb
[ click on images to enlarge ]

On March 14, 2017, methane levels were as high as 2846 ppb, as illustrated by the image on the right. While the origin of these high levels looks hard to determine from this image, the high levels showing up over the East Siberian Arctic Shelf (ESAS) later that day (image underneath) give an ominous warning that destabilization of methane hydrates is taking place.

The images also show that high methane levels are showing up at many other places, e.g. over Antarctica where hydrate destabilization also appears to be taking place, which could also be the cause of noctilucent clouds as discussed in earlier posts (see links at end of this post).

Why is methane erupting from the Arctic Ocean?

Why are increasingly large quantities of methane erupting from the seafloor of the Arctic Ocean? The main driver is warming of the Arctic Ocean that is destabilizing once-permanently-frozen sediments that contain huge amounts of methane in the form of hydrates and free gas.

Ocean heat is increasingly entering the Arctic Ocean from the Atlantic Ocean, as illustrated by the images below. Self-reinforcing feedbacks, in particular sea ice decline, further speed up warming of the Arctic Ocean.

[ from earlier post ]

[ from earlier post ]
Self-reinforcing feedback loops

[ click on images to enlarge ]
Meanwhile, the next El Niño event has already started, at a time when sea surface temperature anomalies over the Pacific Ocean are very high as illustrated by the image on the right showing sea surface temperature anomalies east of South America as high as 5.3°C or 9.5°F (compared to 1981-2011) on February 28, 2017.

Greater contrast between sea surface temperatures and temperatures on land has contributed to flooding in California and South America.

Importantly, more water vapor in the atmosphere results in more warming, since water vapor is a potent greenhouse gas.

[ click on images to enlarge ]
Above images shows ECMWF (European Centre for Medium-Range Weather Forecasts) plumes with strong positive anomalies in all three El Niño regions (on the right).

In other words, temperatures in 2017 look set to be very high, which spells bad news for the Arctic where temperature anomalies are already several times higher than in the rest of the world.

Arctic sea ice looks set to take a steep fall, as illustrated by the image below.


The danger is that further self-reinforcing feedback loops such as albedo decline and methane releases will accelerate warming and, in combination with further warming elements, cause a temperature rise as high as 10°C or 18°F by the year 2026, as described at the extinction page.

The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.


Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Extinction
http://arctic-news.blogspot.com/p/extinction.html

• Warning of mass extinction of species, including humans, within one decade
http://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

• Low sea ice extent contributes to high methane levels at both poles
http://arctic-news.blogspot.com/2017/03/low-sea-ice-extent-contributes-to-high-methane-levels-at-both-poles.html

• Noctilucent clouds indicate more methane in upper atmosphere
http://arctic-news.blogspot.com/2012/09/noctilucent-clouds-indicate-more-methane-in-upper-atmosphere.html

• Noctilucent clouds: further confirmation of large methane releases
http://methane-hydrates.blogspot.com/2013/12/noctilucent-clouds-further-confirmation-of-large-methane-releases.html



Sunday, July 17, 2016

High Methane Levels Follow Earthquake in Arctic Ocean

In the 12 months up to July 14, 2016, 48 earthquakes with a magnitude of 4 or higher on the Richter scale hit the map area of the image below, mostly at a depth of 10 km (6.214 miles).


As temperatures keep rising and as melting of glaciers keeps taking away weight from the surface of Greenland, isostatic rebound can increasingly trigger earthquakes around Greenland, and in particular on the faultline that crosses the Arctic Ocean.

Two earthquakes recently hit the Arctic Ocean. One earthquake hit with a magnitude of 4.5 on the Richter scale on July 9, 2016. The other earthquake hit with a magnitude of 4.7 on the Richter scale on July 12, 2016, at 00:15:24 UTC, with the epicenter at 81.626°N 2.315°W and at a depth of 10.0 km (6.214 miles), as illustrated by the image below.


Following that most recent earthquake, high levels of methane showed up in the atmosphere on July 15, 2016, over that very area where the earthquake hit, as illustrated by the image below.


Above image shows that methane levels were as high as 2505 ppb at an altitude of 4,116 m or 13,504 ft on the morning of July 15, 2016. At a higher altitude (of 6,041 m or 19,820 ft), methane levels as high as 2598 ppb were recorded that morning and the magenta-colored area east of the north-east point of Greenland (inset) looks much the same on the images in between those altitudes. All this indicates that the earthquake did cause destabilization of methane hydrates contained in sediments in that area.

Above image, from another satellite, confirms strong methane releases east of Greenland on the afternoon of July 14, 2016, while the image below shows high methane levels on July 16, 2016, along the faultline that crosses the Arctic Ocean.


The image on the right shows glaciers on Greenland and sea ice near Greenland and Svalbard on July 15, 2016. Note that clouds partly obscure the extent of the sea ice decline.


Above image shows the sea ice on July 12, 2016. There is a large area with very little sea ice close to the North Pole (left) and there is little or no sea ice around Franz Josef Land (right). Overall, sea ice looks slushy and fractured into tiny thin pieces. All this is an indication how warm the water is underneath the sea ice.

[ click on image to enlarge ]
In addition to the shocks and pressure changes caused by earthquakes, methane hydrate destabilization can be triggered by ocean heat reaching the seafloor of the Arctic Ocean. Once methane reaches the atmosphere, it can very rapidly raise local temperatures, further aggravating the situation.

Temperatures are already very high across the Arctic, as illustrated by the image below, showing that on July 16, 2016, it was 1.6°C or 34.8°F over the North Pole (top green circle), while it was 32.7°C or 90.8°F at a location close to where the Mackenzie River flows into the Arctic Ocean (bottom green circle).

Arctic sea ice is in a very bad shape, as also illustrated by the Naval Research Laboratory nowcast below.


Sea ice thickness has fallen dramatically over the years, especially the ice that was more than 2.5 m thick. The image below compares the Arctic sea ice thickness (in m) on July 15, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.

[ Click on image to enlarge ]
The image below shows sea surface temperature anomalies from 1961-1990 on July 24, 2016.


Sea surface temperatures off the coast of America are high and much of this ocean heat will be carried by the Gulf Stream toward the Arctic Ocean over the next few months.


On July 24, 2016, sea surface temperature near Florida was as high as 33.2°C or 91.7°F, an anomaly of 3.7°C or 6.6°F from 1981-2011 (bottom green circle), while sea surface temperature near Svalbard was as high as 17.3°C or 63.2°F, an anomaly of 12.6°C or 22.8°F from 1981-2011 (top green circle).

A cold freshwater (i.e. low salinity) lid sits on top of the ocean and this lid is fed by precipitation (rain, hail, snow, etc.), melting sea ice (and icebergs) and water running off the land (from rivers and melting glaciers on land). This lid reduces heat transfer from ocean to atmosphere, and thus contributes to a warmer North Atlantic where huge amounts of heat are now carried underneath this lid toward the Arctic Ocean. The danger is that more ocean heat arriving in the Arctic Ocean will destabilize clathrates at the seafloor and result in huge methane eruptions, as discussed in earlier posts such as this one.

As temperatures keep rising, snow and ice in the Arctic will decline. This could result in some 1.6°C or 2.88°F of warming due to albedo changes (i.e. due to decline both of Arctic sea ice and of snow and ice cover on land). Additionally, some 1.1°C or 2°F of warming could result from methane releases from clathrates at the seafloor of the world's oceans. As discussed in an earlier post, this could eventuate as part of a rise from pre-industrial levels of as much as 10°C or 18°F, by the year 2026.

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The impact of rising temperatures will be felt firstly and most strongly in the Arctic, where global warming is accelerating due to numerous feedbacks that can act as self-reinforcing cycles.

Already now, this is sparking wildfires across the Arctic.

Above image shows wildfires (indicated by the red dots) in Alaska and north Canada, on July 15, 2016.

The image on the right shows smoke arising from wildfires on Siberia. The image below shows that, on July 18, 2016, levels of carbon monoxide (CO) over Siberia were as high as 32318 ppb, and in an area with carbon dioxide (CO2) levels as low as 345 ppm, CO2 reached levels as high as 650 ppm on that day.

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The image below shows the extent of smoke from wildfires in Siberia on July 23, 2016.


The image below shows high methane levels over Siberia on July 19, 2016.


The image below, from the MetOp satellite, shows high methane levels over Siberia on July 21, 2016.

Below are further images depicting mean global methane levels, from 1980-2016 (left) and 2012-2016 (right).

The image below shows methane levels at Barrow, Alaska.


The image below shows that, while methane levels may appear to have remained stable over the past year when taking measurements at ground level, at higher altitudes they have risen strongly.


The conversion table below shows the altitude equivalents in feet, m and mb.
57016 feet44690 feet36850 feet30570 feet25544 feet19820 feet14385 feet 8368 feet1916 feet
17378 m13621 m11232 m 9318 m 7786 m 6041 m 4384 m 2551 m 584 m
 74 mb 147 mb 218 mb 293 mb 367 mb 469 mb 586 mb 742 mb 945 mb

The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.