Heatwave to hit Greenland

A heatwave with temperature anomalies exceeding 36°F (20°C) is expected to hit Greenland between August 16 and 22, 2014, as illustrated by the image on the left and the animation on the right. 

Such heatwaves can be expected to hit the Arctic more frequently and with greater intensity, as temperatures in the Arctic are rising faster than elsewhere on Earth.

Such heatwaves can result in massive melting on Greenland, as persistent heat changes the texture of the snow and ice cover, in turn reducing its reflectivity. This makes that less sunlight is reflected back into space and is instead absorbed. 

The image below illustrates what a difference the presence of sea ice can make.

from: Arctic Warming due to Snow and Ice Demise

As the NSIDC/NOAA graphs below shows, melting on Greenland has been relatively modest this year when compared to the situation in 2012. By July 12, 2012, 97% of the ice sheet surface had thawed, according to this NASA analysis and this NOAA Arctic Report Card.

Melting on Greenland directly affects sea level rise, and melting on Greenland is accelerating due to a number of factors.

Projections of melting on Greenland have long been based on a warming atmosphere only, ignoring the warmer waters that lubricate glaciers and that warm Greenland's bedrock canyons that sit well below sea level.

Furthermore, there are growing quantities of black carbon deposits as a result of burning of fossil fuel and biomass. High temperatures have recently caused ferocious wildfires in Canada that have in turn caused a lot of black carbon to go up high into the atmosphere.

And of course, the atmosphere over the Arctic is warming up much faster than most models had projected. This in turn causes triggers further feebacks, including more extreme weather events such as heatwaves and rain storms that can be expected to hit Greenland with ever more frequency and ferocity. Further feedbacks include methane eruptions from the heights of Greenland, as discussed at the Arctic Feedbacks Page.

When also taking into account the accelerating impact of such factors on melting in Greenland, sea levels could rise much faster than anticipated, as illustrated by the image below.

from: more than 2.5m sea level rise by 2040? 

Note that sea level rise is only one of the many dangers of global warming, as discussed in the 2007 post Ten Dangers of Global Warming.

The image on the right shows a temperature forecast for August 16, 2014, with parts of Greenland changing in color from blue into green, i.e. above the melting point for snow and ice.

Such high temperatures are now hitting locations close to the North Pole ever more frequently, due to the many feedbacks that are accelerating warming in the Arctic, as discussed at this Feedbacks page.

One of the most dangerous feedbacks is a sudden eruption of huge quantities of methane from the seafloor of the Arctic Ocean, as discussed in a recent post.

The impact of such feedbacks can be accumulative and interactive, resulting in self-reinforcing feedbacks loops that can escalate into runaway warming.

Below is another forecast by ClimateReanalyzer for August 16, 2014, showing the remarkable ‘greening’ of Greenland, as well as the very high temperatures reaching the higher latitudes of North America.

Also see the very high sea surface temperatures around Greenland on the image below, created with ClimateReanalyzer.

Sea surface temperature anomalies on August 15, 2014. 

In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog. 

Post by Sam Carana.

More than 2.5m Sea Level Rise by 2040?

A warming period more than 400,000 years ago pushed the Greenland ice sheet past its stability threshold (which may have been no more than several degrees above pre-industrial temperatures). This resulted in a nearly complete deglaciation of southern Greenland, raising global sea levels some 4.5-6 meters, found a recent study by Reyes et al. Due to melting elsewhere, global mean sea level then was 6 to 13 metres above the present level. Indeed, melting of the entire West Antarctic Ice Sheet can add a further 6-meter rise in sea levels. If the East Antarctic Ice Sheet (EAIS) were to melt as well, sea levels would rise by around 70 metres.

Sea level is now rising by 3.1mm (0.122 inch) per year. Much of this rise is due to rising temperatures, but there are also other factors. One quarter of the rise results from groundwater depletion, while run off from melting ice and glaciers adds another quarter and the remainder is attributed to thermal expansion of sea water. Furthermore, as temperatures rise, feedbacks start to kick in, e.g. the kinetic energy from stronger waves and more intense storms can speed things up.

Clearly, a rapid multi-meter rise would be devastating as it would flood many coastal cities, as well as much of the land now used to grow food. By how much have sea levels been rising recently and how fast can they be expected to rise in the near future?

NASA image, data by the JPL PODAAC, in support of the NASA's MEaSUREs program.

Sea levels have risen by some 60 mm over the past 20 years, as above NASA image shows, which has a linear trendline added. The question is whether a linear trendline is the most appropriate trendline, given that it suggests that a similar rise could be expected over the next 20 years. A polynomial trendline appears to fit the data better, as the animation below shows.

Such a polynomial trendline, however, points at a similar rise (of some 50 mm) in just four years time, with an even more steeper rise to follow, as illustrated by the image below.

And indeed, such a rise doesn't slow down there. A polynomial trendline applied to the data points at a sea level rise of more than 2.5 m (8.2 ft) by the year 2040.

The image below gives an idea of what a sea level rise of six feet (1.829 m) would do to the City of New York. Of course, this is only the sea level rise. Storm surge would come on top of this, as discussed at Ten Dangers of Global Warming.

So, what would be more appropriate, to expect sea levels to continue to rise in a linear way, or to take into account feedbacks that could speed things up? Where such feedbacks could lead to is illustrated by the image below.

[ from: How many deaths could result from failure to act on climate change? click on image to enlarge ]

This calls for comprehensive and effective action, as discussed at the Climate Plan blog.


References

- South Greenland ice-sheet collapse during Marine Isotope Stage 11, Reyes et al. (2014)
http://www.nature.com/nature/journal/v510/n7506/full/nature13456.html

- Nonsustainable groundwater sustaining irrigation: A global assessment, Yoshihide Wada et al. (2012)
http://onlinelibrary.wiley.com/doi/10.1029/2011WR010562/abstract

- Groundwater Depletion Linked to Rising Sea Levels
http://www.waterworld.com/articles/2010/11/groundwater-depletion-linked-to-rising.html

- Assessment of the Jason-2 Extension to the TOPEX/Poseidon, Jason-1 Sea-Surface Height Time Series for Global Mean Sea Level Monitoring, Beckley et al. (2010)
http://www.tandfonline.com/doi/abs/10.1080/01490419.2010.491029

- Feedbacks in the Arctic
http://climateplan.blogspot.com/p/feedbacks.html

- How many deaths could result from failure to act on climate change? (2014)
http://arctic-news.blogspot.com/2014/05/how-many-deaths-could-result-from-failure-to-act-on-climate-change.html

Post by Sam Carana.

Has the descent begun?

On March 9, 2014, Arctic sea ice area was at a record low for the time of the year, at only 12.88731 square kilometers.

Sea ice extent shows a similar descent, as illustrated by the NSIDC image below.

NSIDC update: The image below shows that Arctic sea ice extent was 14.583 square kilometers on March 11, 2014 (light green line), a record low for this time of the year and smaller than it was in 2006 (magenta line) and 2011 (orange line) at this time of the year.

The situation is dire, given that methane concentrations have risen strongly following an earthquake that hit the Gakkel Ridge on March 6, 2014, as illustrated by the image below.

[ click on image to enlarge ]

Huge amounts of methane have been released from the seafloor of the Arctic Ocean over the past half year, and the resulting high methane concentrations over the Arctic will contribute to local temperature rises.

The image below shows that sea surface temperatures are anomalously high in the Arctic Ocean and off the east coast of North America, from where warm water is carried by the Gulf Stream into the Arctic Ocean.

The prospect of an El Niño event makes the situation even more dire. NOAA recently issued an El Niño Watch. This follows a conclusion by an international research team that found a 75% likelyhood of an El Niño event in late 2014.

The consequences of sea ice collapse would be devastating, as all the heat that previously went into transforming ice into water will be asbsorbed by even darker water, from where less sunlight will be reflected back into space. The danger is that further warming of the Arctic Ocean will trigger massive methane releases is unacceptable and calls for comprehensive and effective action as discussed at the Climate Plan blog.



Related

- M4.5 Earthquake hits Gakkel Ridge
http://arctic-news.blogspot.com/2014/03/m45-earthquake-hits-gakkel-ridge.html

- Climate Plan blog
http://climateplan.blogspot.com

Post by Sam Carana.

M4.5 Earthquake hits Gakkel Ridge

The above image shows recent large methane release over the Gakkel Ridge, the faultline that crosses the Arctic Ocean between the northern tip of Greenland and the Laptev Sea (red line on map). Methane readings were as high as 2395 ppb at 586 mb, an altitude that often shows high methane readings originating from the Arctic Ocean.

An earthquake with a magnitude of 4.5 hit the Gakkel Ridge at a depth of 2 km on March 6, 2014, at 11:17.17.0 UTC. The location is shown on the map below.

[ click on image to enlarge ]

The image below shows more recent methane readings, around March 8, 2014.

The image below is a Naval Research Laboratory forecast of sea ice thickness for March 8, 2014, run on March 3, 2014.

Meanwhile, the sea ice is close to record lows (for the time of the year), as illustrated by the images below. The image directly below shows sea ice area.

The image below shows sea ice extent.

The image below, by Wipneus, shows sea ice volume.

The image below, by Andy Lee Robinson, offers a different way of looking at sea ice volume, the Arctic Death Spiral.

Post by Sam Carana.

High methane levels over the Arctic Ocean on February 17, 2014

Above image shows IASI methane readings over the last day or so, when levels as high as 2223 ppb were recorded.

Where does the methane come from?

On above image, methane shows up prominently along the faultline that crosses the Arctic Ocean from the northern tip of Greenland to the Laptev Sea. This indicates that the methane originated from the depths of the Arctic Ocean, where sediments contain large amounts of methane in the form of free gas and hydrates, which have become destabilized.

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

[ from earlier post, click on image to enlarge ]

Below is a comparison of methane readings for the week from February 9 to 16, 2014, compared to the same period in 2013.

[ from earlier post, click on image to enlarge ]

The above comparison shows that there is a lot of methane over the Arctic Ocean that wasn't there last year. 

Furthermore, high methane readings show up where currents move the sea ice out of the Arctic Ocean, in areas such as Baffin Bay. This indicates that methane that is released from the seafloor of the Arctic Ocean appears to be moving underneath the ice along with exit currents and entering the atmosphere where the sea ice is fractured or thin enough to allow the methane to pass through. 

Also note that more orange areas show up on the southern hemisphere in 2014, indicating that more methane from the northern hemisphere is now spreading south beyond the equator. This in addition to indications that more methane is rising and building up at higher altitudes, as discussed in an earlier post.

Causes

What made these high releases from the seafloor of the Arctic Ocean persist for so long? At this time of year, one might 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 fallen much at the center of the Arctic Ocean between early October, 2013 (left) and February 17, 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 ]

The above comparison image shows that, while surface temperatures in the Atlantic Ocean may have fallen strongly with the change of seasons, surface 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 (if at all) compared to early October 2013, since the Gulf Stream has continued to push warmer water into the Arctic, i.e. water warmer than the water in the Arctic Ocean, so the heating impact of the Gulf Stream continues. Also, sea surface temperature anomalies along the path of the Gulf Stream continue to be anomalously high, as the image below shows.

The situation looks even more grim on the Climate Reanalyzer image below, showing sea surface temperature anomalies that are far more profound in the Arctic Ocean.

Note also that, 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 February 17, 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 showing up closer to the faultline that runs through the Arctic Ocean from the top of Greenland to the Laptev Sea.


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. 4½ 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. The poster below illustrates the danger.

[ click on image to enlarge - note that this is a 4.9 MB file that may take some time to fully load ]

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.

Methane released from the Arctic Ocean seafloor has contributed to high surface temperature anomalies over the Arctic Ocean in a number of ways. As a potent greenhouse gas, methane is trapping heat that would otherwise radiate into space. Furthermore, methane rising through the sea ice reduces growth of the sea ice.

The danger 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.

Post by Sam Carana.

High methane readings over Greenland

High methane readings have been recorded over Greenland since the start of February 2014. The image below shows methane readings of 1950 ppb and higher in yellow on February 9, 2014.

The animation below shows that high methane readings (1950+ ppb in yellow) have been showing up over Greenland since the start of February 2014.

[ Note: this animation is a 3.28 MB file that may take some time to fully load ]

What could have caused these high methane readings? The persistence with which the methane shows up over Greenland indicates that it did indeed originate from Greenland.

The above animation also illustrates that high methane readings show up every other image. The IASI readings come from a satellite that is orbiting the poles twice daily, with a 12-hour interval, so the satellite passes the North Pole twice every day. This makes that the images follow a day-versus night pattern, indicating that the high methane readings follow a circadian rhythm, suggesting a pattern that is in line with temperature differences between day and night.

There often is a difference in methane readings between day and night, but rarely is it as distinct as is currently the case over Greenland. And indeed, more is currently happening to temperatures over Greenland than mere differences in temperature between day and night.

As discussed in earlier posts such as this one, the once-common temperature difference between the Arctic and lower latitudes has been shattered, and this is weakening the Jet Stream and the Polar Vortex, in turn making it easier for cold air to flow down to lower latitudes and for warmer air to enter the Arctic. As a result, temperatures over Greenland can go from one extreme to another and back, as illustrated by the image with selected cci-reanalyzer.org forecasts below.

[ click on image to enlarge ]

Above image shows that, in some areas over Greenland, temperature anomalies may go down as low as as minus 20 degrees Celsius one day, then climb as high as 20 degrees Celsius a few days laters, to hit temperature anomalies as low as minus 20 degrees Celsius again some days later. These are swings of 40 degrees Celsius that can hit an area over the course of a few days. 

This could explain the methane over Greenland. Methane is present in the Greenland ice sheet in the form of hydrates and free gas. These huge temperature swings are causing the ice to expand and contract, thus causing difference in pressure as well as temperature. The combined shock of wide pressure and temperature differences is causing movement and fractures in the ice allowing methane to rise to the surface and enter the atmosphere.

The image below puts things in perspective, comparing methane over Greenland with methane over the Arctic Ocean.

Above image shows that the amounts of methane over Greenland are huge, while methane is still being released from the seafloor of the Arctic Ocean, in particular along the faultline that runs from the north of Greenland to the Laptev Sea. 

Few people seem to have anticipated these methane releases from the mountains of Greenland. Even worse, similar processes could be going at times on Antarctica, the Himalayas and the Qinghai-Tibet Plateau. I warned about this danger, e.g. in the May 2013 post Is Global Warming breaking up the Integrity of the Permafrost?. The danger that methane will be released in large (and growing) quantities from hydrates and free gas contained in the ice over mountains appears to have been ignored by the IPCC, which puts more weight on my estimate that methane release from hydrates currently amounts to 99 Tg annually, vastly more than the most recent IPCC estimates of 6 Tg per year. 

Without action on climate change, these methane releases threaten to rise even further and cause runaway global warming. This calls for comprehensive and effective action as discussed at the Climate Plan blog. 

Post by Sam Carana.

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.

Post by Sam Carana.