Showing posts with label Arctic. Show all posts
Showing posts with label Arctic. Show all posts

Friday, March 22, 2024

Atlantic ocean heat threatens to unleash methane eruptions

The image below shows that the monthly Atlantic surface temperature anomaly in February 2024 was 1.176°C when compared to a 1951-1980 base.

[ click on images to enlarge ]

The image below shows that the monthly Atlantic surface temperature anomaly in February 2024 was 1.435°C when compared to a 1901-2000 base. 


The difference illustrates the importance of selecting a base to calculate anomalies from. The anomaly indicates how much heat has accumulated in the Atlantic, and it is even larger for February 2024 when using a genuinely pre-industrial base, as discussed earlier.

The images also highlight the potential for the slowing down of the Atlantic meridional overturning circulation (AMOC) to contribute to more heat accumulating at the surface of the Atlantic Ocean.

As temperatures rise, many feedbacks are kicking in with greater ferocity, including increased stratification of oceans, loss of sea ice, loss of reflectivity of clouds and increased freshwater due to stronger melting of sea ice and glacial ice, due to heavier runoff from land and rivers and due to changes in ocean circulation.

While this may look to cause less ocean heat to reach the Arctic Ocean at the moment, the result is that a huge amount of ocean heat is accumulating in the North Atlantic that threatens to abruptly move into the Arctic Ocean. The danger is that an influx of ocean heat can cause large amounts of methane to erupt from the seafloor of the Arctic Ocean. 

The inset on the top image illustrates that, as people's emissions raise the temperature, this rise can strengthen wind, evaporation, ocean currents and rainfall locally, resulting in greater potential for a lid to form and spread at the surface of the North Atlantic. As temperatures rise and winds strengthen, more evaporation can occur in one place and more rain can then fall further down the path of the Gulf Stream, i.e. an ocean current that extends into the Arctic Ocean, as part of AMOC. This rain further contributes to the freshwater accumulation at the surface of the North Atlantic.

In the video below, Guy McPherson discusses a recent study by Marilena Oltmanns et al. on some of these issues.


This page further discusses formation of a cool freshwater lid at the surface of the North Atlantic and the contribution to this of Jet Stream changes. The image below shows that the Jet Stream reached speeds as high as 455 km/h or 283 mph north of Washington on February 18, 2024 03:00 UTC, with Instantaneous Wind Power Density as high as 387.5 kW/m².

From earlier post Blue Ocean Event 2024?

A huge amount of ocean heat is accumulating in the North Atlantic and threatens to abruptly move into the Arctic Ocean. The danger is that, due to strong wind along the path of the Gulf Stream, huge amounts of ocean heat will abruptly get pushed into the Arctic Ocean, with the influx of ocean heat causing destabilization of hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane. 

Strong hurricanes can significantly add to the danger. More hurricanes are forecast for the 2024 Atlantic hurricane season than during 1950-2020, as illustrated by the image below. 


Many of the dangers have been discussed before, e.g. the danger that sea currents in the Arctic Ocean will change direction, in this 2017 post. 

Arctic sea ice thickness warning

The compilation image below shows Arctic sea ice on March 28, 2024. The satellite image (left) may indicate extensive sea ice, but clouds can obscure things. The other image (right) indicates that sea ice in a large area from the Laptev Sea down to the North Pole may be very thin.


The image below illustrates the decline of Arctic sea ice volume over the years.


The images above and below show that Arctic sea ice volume has recently been the lowest on record for the time of year.


Given that Arctic sea ice currently is still relatively extensive, this low volume indicates that sea ice is indeed very thin, which must be caused by ocean heat melting sea ice from below, since little or no sunshine is yet reaching the Arctic at the moment and air temperatures are still far below freezing point, so where ocean heat may be melting sea ice away from below, a thin layer of ice will quickly be reestablished at the surface. 

This situation looks set to dramatically change over the next few months, as air temperatures will rise and as more ocean heat will reach the Arctic Ocean. Moreover, as illustrated by the map below, much of the thicker sea ice is located off the east coast of Greenland. This sea ice and the purple-colored sea ice can be expected to melt away quickly with the upcoming rise in temperatures over the next few months.


Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.


Links

• Climate Reanalyzer

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• European summer weather linked to North Atlantic freshwater anomalies in preceding years - by Marilena Oltmanns et al.
https://wcd.copernicus.org/articles/5/109/2024/wcd-5-109-2024-discussion.html
discussed at facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161330866254679

• Science Snippets: Arctic Sea Ice Affects European Summers, Marine Life, and All Life on Earth - by Guy McPherson
https://www.youtube.com/watch?v=X09vtWNDuDw

• nullschool 
https://earth.nullschool.net

• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

• Extended range forecast of Atlantic seasonal hurricane activity and landfall strike probability for 2024 - by Philip Klotzbach et al.
https://tropical.colostate.edu/forecasting.html
discussed on facebook at:
https://www.facebook.com/groups/arcticnews/posts/10161346323759679

• Arctic Ocean Feedbacks
https://arctic-news.blogspot.com/2017/01/arctic-ocean-feedbacks.html

• NASA Worldview satellite images
https://worldview.earthdata.nasa.gov

• University of Bremen - Arctic sea ice
https://seaice.uni-bremen.de/start

• Danish Meteorological Institute - Arctic sea ice volume and thickness


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Friday, February 2, 2024

Blue Ocean Event 2024?

How likely is an Arctic Blue Ocean Event (BOE) to occur in 2024 or even a Double BOE? The image below is alarming. 


The highest daily sea surface temperatures on record (going back to 1981) were reached in February 2024, even higher than the peaks in 2023. Even higher temperatures may be reached over soon, in March 2024 and April 2024.

As the above image shows, the highest temperatures for the year are typically reached in March. This was the case for the previous years on record, except for 2023 when the current El Niño started to emerge and when the highest peak for the year occurred in August. According to NOAA, the majority of models indicate that this El Niño will persist through March-May 2024. 

Antarctic sea ice extent typically reaches an annual minimum end February, while Arctic sea ice extent typically reaches an annual minimum in September, after a steep decline resulting from more sunlight reaching higher latitudes North and ocean heat reaching a second peak in August.   

Ominously, daily surface air temperatures in the Southern Hemisphere exceeded 17°C recently, something that never happened before in the record going back to 1981. Antarctic sea ice extent typically reaches an annual minimum end February. Loss of sea ice acts as a self-reinforcing feedback loop, accelerating the temperature rise. The daily surface air temperature in the Southern Hemisphere was 17.005°C on Feb 1, 2024, following a peak of 17.01°C on Jan 31, 2024.


Higher temperatures can cause sea ice to melt, even out of season

As illustrated by the image below, adapted from Pidwirny, sunlight does not reach the North Pole until the March Equinox. From that time on, insolation rises steeply. Around the June Solstice, more sunlight reaches the North Pole than anywhere else on Earth. In the image below, insolation is calculated taking into account the combined effects of angle of incidence and day length duration. 

The conclusion is that ocean heat is the main reason why melting of Arctic sea ice can occur early in the year. More specifically, the narrowing of the temperature difference between the Arctic and the Tropics can at times cause strong wind to be present along the path of the Gulf Stream. Rising ocean heat combined with strong wind can cause heat to move abruptly toward the Arctic Ocean, causing sea ice to fall in extent. 

Such an event is illustrated by the image below, adapted from NSIDC. The image shows a drop in sea ice extent at the end of January 2024 (blue), a time of year when Arctic sea ice is still expected to increase in extent and to keep increasing in extent for some time to come (grey). In this case, strong wind may have caused a huge amount of ocean heat that is present in the North Atlantic to move abruptly toward the Arctic Ocean, as discussed in an earlier post. 

For the time of year, Arctic sea ice extent is currently still extensive, compared to earlier years, which is a reflection of more water vapor in the atmosphere and more precipitation. While sea ice extent is relatively large, sea ice volume is among the lowest of all years on record for the time of year, as illustrated by the image below. 

This indicates that Arctic sea ice is very thin. Ominously, the image below indicates that there is a huge area near the North Pole with very thin sea ice. 


Furthermore, much of the thicker sea ice is located off the east coast of Greenland, which means that this sea ice is likely to melt away quickly as more sunlight starts reaching the Northern Hemisphere and temperatures rise in line with seasonal changes (see the insolation image further above).


The North Atlantic sea surface temperature was 20.4°C on February 15, 2024, i.e. 0.6°C higher than on February 15, 2023.

High North Atlantic sea surface temperatures spell bad news for the Arctic, as much ocean heat gets pushed toward the Arctic from the North Atlantic. 

North Atlantic sea surface temperatures are just starting to heat up from their annual minimum and can be expected to rise strongly, in line with seasonal changes. 

[ click on images to enlarge ]
Ominously, a peak temperature of 25.4°C was reached on Aug.31, 2023, much higher than the peak in any of the preceding years dating back to 1981.

During the six months between the September Equinox and the March Equinox (see image further above), no sunlight is reaching the North Pole. 

Nonetheless, temperature anomalies in the Arctic are already extremely high, due to ocean heat that has entered the Arctic Ocean from the North Atlantic, as illustrated by the two maps on the right and the two maps on the right further below.

Northern Hemisphere Sea Surface Temperature Anomalies were as much as 12.6°C or 22.7°F higher than 1981-2011 on February 15, 2024, locarion marked by the green circle on the image below.


Feedbacks 

Slowing down of AMOC and cooling due to heavier melting of Greenland's ice is causing less ocean heat to reach the Arctic Ocean, while a huge amount of ocean heat is accumulating in the North Atlantic, as it did in 2023. A large part of this heat in the North Atlantic can also be present underneath the sea surface.

These developments occur at the same time as ocean stratification increases (as temperatures rise, see above images), as more freshwater enters the ocean (as a result of more meltwater and of runoff from land and from rivers), and as more evaporation takes place and more rain falls further down the path of the Gulf Stream, all of which can contribute to formation and growth of a cold, freshwater lid at the surface of the North Atlantic.

[ cold freshwater lid on North Atlantic ]

Furthermore, storms can get stronger as temperatures rise and as changes take place to the Jet Stream. Strong wind can temporarily speed up currents that carry huge amounts of ocean heat with them toward the Arctic Ocean, as discussed in earlier posts such as this one. Much of the ocean heat in the North Atlantic can therefore be pushed abruptly underneath this freshwater lid and flow into the Arctic Ocean. The image below shows that the Jet Stream reached speeds as high as 455 km/h or 283 mph north of Washington on February 18, 2024 03:00 UTC, with Instantaneous Wind Power Density as high as 387.5 kW/m².


The image below shows wind speed at 250 hPa on a background of sea surface temperature anomalies versus 1981-2011. 


The danger is that, due to strong wind along the path of the Gulf Stream, huge amounts of ocean heat will abruptly get pushed into the Arctic Ocean, with the influx of ocean heat causing destabilization of hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

Changes to the Jet Stream and ocean heat accumulating in the North Atlantic Ocean are both consequences of the overall temperature rise. A distorted Jet Stream can cause an abrupt influx of ocean heat into the Arctic Ocean.

Such additional ocean heat, combined with a steep rise in insolation hitting the Arctic in April and May, may suffice to cause a Blue Ocean Event (BOE) to occur in 2024.

[ click on images to enlarge ]
The far North has the highest temperature anomalies, they can as high as 7.04°C, as the image on the right shows.

A BOE occurs when virtually all sea ice disappears and less than 1 million km² of sea ice remains. As the sea ice disappears, the surface color changes from white (sea ice) to blue (ocean) resulting in far more sunlight getting absorbed by the Arctic Ocean, instead of getting reflected back into space as was previously the case.

Albedo change constitutes a huge self-reinforcing feedback loop, i.e. the more sea ice disappears, the more sunlight gets absorbed by the Arctic Ocean, further accelerating sea ice melting. 

[ Albedo change, from the Albedo page ]

Next to the albedo loss, there is loss of the latent heat buffer constituted by the sea ice. Latent heat is energy associated with a phase change, such as the energy consumed when solid ice turns into water (i.e. melts). During a phase change, the temperature remains constant. Sea ice acts as a buffer that absorbs heat, while keeping the temperature at about zero degrees Celsius. As long as there is sea ice in the water, this sea ice will keep absorbing heat, so the temperature doesn't rise at the sea surface.

The amount of energy absorbed by melting ice is as much as it takes to heat up an equivalent mass of water from zero to 80°C. 

Without the buffer constituted by thicker sea ice, an influx of ocean heat could destabilize hydrates contained in sediments at the seafloor of the Arctic Ocean, resulting in eruptions of huge amounts of methane.

[ click on images to enlarge ]
The above image illustrates these tipping points and Northern Hemisphere Ocean Temperature anomalies vs 1901-2000, created with NOAA data. Trends and tipping point estimates are added. The magenta trend is based on Jan.1880-Jan.2024 data and warns that the Seafloor Methane Tipping Point may be crossed in 2025. The red trend is based on Jan.2010-Jan.2024 data and better reflects variables such as El Niño, and it warns that the Seafloor Methane Tipping Point may be crossed in 2024. 


The above image, adapted from tropicaltidbits.com, shows a forecast for November 2024 of the 2-meter temperature anomaly in degrees Celsius, based on 1984-2009 model climatology. The anomalies are forecast to be very high for the Arctic Ocean.

Many additional feedbacks are active, such as changes to the Jet Stream and slowing down of AMOC, and they could speed up the crossing of such tipping points, as also discussed at the feedbacks page. The danger is that a cascade of events will unfold like a domino effect, leading to extinction of most species, including humans, as the image below warns. 

[ from earlier post - click on images to enlarge ]

Greenhouse gases rising

Meanwhile, concentrations of greenhouse gases keeps rising, as illustrated by the image below. 

The average daily carbon dioxide (CO₂) at Mauna Loa, Hawaii, was 426.21 ppm (parts per million) on February 4, 2024. The weekly average was 425.83 ppm. 

Critical is the rate of change, in particular the rapid rise in temperatures and greenhouse gas concentrations. To find higher CO₂ concentrations, one has to go back millions of years. 


A recent study concludes that: 
- A doubling of CO₂ is predicted to warm the planet a whopping 5°C to 8°C.
- The last time atmospheric CO₂ consistently reached today’s human-driven levels of 420 ppm was 14 million years ago.
- The hottest period was about 50 million years ago, when temperatures were as much as 12°C higher than today.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.



Links

• Blue Ocean Event
https://arctic-news.blogspot.com/p/blue-ocean-event.html

• Climate Reanalyzer - Daily Sea Surface Temperature, World (60°S-60°N)
https://climatereanalyzer.org/clim/sst_daily

• Pidwirny, M. "Earth-Sun Relationships and Insolation". Fundamentals of Physical Geography, 2nd Edition (2006)
http://www.physicalgeography.net/fundamentals/6i.html

• NOAA - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf 

• NSIDC - Arctic sea ice extent
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph

• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• University of Bremen - Arctic sea ice

• Scripps Institution of Oceanography at UC San Diego.

• Toward a Cenozoic history of atmospheric CO₂ - by The Cenozoic CO₂ Proxy Integration Project (CenCO₂PIP) Consortium






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Sunday, January 14, 2024

Seafloor methane tipping point crossed in 2024?

The heat in December 2023 was felt most strongly in the Arctic, as illustrated by the NASA image below, showing anomalies above 1951-1980 as high as 9.9°C. 
. 

The image below further illustrates heat striking the northern latitudes in 2023, showing that the temperature anomaly in 2023 was 2.19°C above 1880-1920 in between 24°North and the North Pole. 


The danger is that ocean heat could abruptly be pushed from the North Atlantic into the Arctic Ocean, temporarily raising temperatures at the seafloor of the Arctic Ocean, as discussed in earlier posts such as this one. 

Terrifying rise of Northern Hemisphere ocean temperature anomalies

The image shows the terrifying rise of Northern Hemisphere ocean temperature anomalies from 1901-2000, illustrating crossing of two tipping points, i.e. the Latent Heat Tipping Point and the Seafloor Methane Tipping Point.

This threatens to cause rapid destabilization of methane hydrates at the seafloor of the Arctic Ocean and lead to explosive eruptions of methane, as its volume increases 160 to 180-fold when leaving the hydrates. 


The image is an update of the image below, from a 2023 post and added here for reference purposes. Check out that post for more on the Latent Heat tipping Point and the Seafloor Methane Tipping Point.


Note that the above analyses are for annual data. An earlier analysis using monthly data shows that the seafloor methane tipping point was reached in August 2023. 

The danger is that, as the latent heat buffer disappears, incoming ocean heat can no longer be consumed by sea ice, but will instead heat up sediments at the seafloor of the Arctic ocean.

Latent heat loss, feedback #14 on the Feedbacks page
Ominously, sea surface temperatures (60°South-60°North) are on the rise in 2024, as illustrated by the image below.


The image below, adapted from NOAA, shows how high temperatures line up with El Niño months.

[ click on images to enlarge ]

Annual temperature anomalies as high as 2.5°C above pre-industrial

The temperature anomaly in 2023 may be as high as 2.5°C above pre-industrial, as illustrated by the image below.


For more on the analysis behind this potential rise of 2.5°C, see the pre-industrial page. Acknowledging the full strength of the rise is important, because of the feedbacks that come with it. Rising temperatures result in more water vapor getting in the atmosphere (7% more water vapor for every 1°C warming), further amplifying the temperature rise, since water vapor is a potent greenhouse gas. 

The IPCC likes people to believe that the temperature rise is only 1.1°C above pre-industrial, in which case there would be only 7.7% more water vapor in the atmosphere, but with a 2.5°C rise, there would be 17.5% more water vapor in the atmosphere. Those who seek to downplay the danger act as if changes to the Jet Stream and to ocean currents, Arctic sea ice, methane and water vapor can all be ignored.

Humans will likely go extinct with a 3°C rise. The image below shows annual mean global surface temperature (Land-Ocean) created with NASA Land-Ocean temperature anomaly versus 1902-1920, further adjusted by 0.99°C to reflect ocean air temperature, higher polar anomalies and an earlier (pre-industrial) base. The blue line shows a polynomial trend based on 1880-2023 data, indicating that a 3°C rise could eventuate by 2035. The magenta line shows a polynomial trend based on data from a shorter period (2010-2023), which better reflects short term variables such as El Niño and which indicates that a 3°C rise could eventuate as early as in 2024, i.e. this year. 


Note again that the above analyses are for annual data. An earlier analysis using monthly data shows that the September 2023 NASA Land+Ocean temperature was 1.78°C higher than it was in September 1923. The anomaly is 1.74°C when compared to a base centered around the year 1900 (1885-1915). This 1.74°C anomaly can be adjusted by 0.99°C to reflect a pre-industrial base, air temperature and higher polar anomalies, adding up to a potential anomaly of 2.73°C.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at the Climate Emergency Declaration group.


Links

• NASA - GISS Surface Temperature Analysis
https://data.giss.nasa.gov/gistemp

• Sea surface temperature at record high
https://arctic-news.blogspot.com/2023/03/sea-surface-temperature-at-record-high.html

• 2024 looks to be worse than 2023
https://arctic-news.blogspot.com/2024/01/2024-looks-to-be-worse-than-2023.html

• Climate Reanalyzer - Daily sea surface temperatures
https://climatereanalyzer.org/clim/sst_daily

• NOAA - Northern Hemisphere ocean temperature anomalies vs 1991-2020
https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/global/time-series/nhem/ocean/12/12/1850-2023

• NOAA - Monthly temperature anomalies versus El Niño
https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202313/supplemental/page-2

• NOAA - Climate Prediction Center - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• Albedo, latent heat, insolation and more
https://arctic-news.blogspot.com/p/albedo.html

• Latent Heat
https://arctic-news.blogspot.com/p/latent-heat.html

• The Threat of Global Warming causing Near-Term Human Extinction
https://arctic-news.blogspot.com/p/threat.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• When Will We Die?

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

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

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html

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Friday, November 17, 2023

Arctic Ocean Heatstroke

[ discussed at facebook ]
The above image illustrates how much hotter October 2023 was in the Northern Hemisphere, compared to October in other years. The temperature in October 2023 was more than 2°C above October in 1880-1920, in the Northern Hemisphere, even with 3 years smoothing. Note that 1880-1920 is not pre-industrial, when using a base that is genuinely pre-industrial, the anomaly would be even higher.


The above image, adapted from Climate Reanalyzer, and the image below, adapted from NASA, both use the same 1951-1980 baseline to illustrate the October 2023 temperature anomaly.


Anomalies are very high, especially over the Arctic Ocean, which reflects the enormous amounts of heat that are transferred from the Arctic Ocean to the atmosphere.

There are further reasons behind the very high anomalies over the Arctic, one of which is methane, which has risen very fast over the years.

The image on the right illustrates methane's historic rise, showing IPCC and, more recently, WMO data. Methane (CH₄) reached 1923 parts per billion (ppb) in 2022, 264% of the 1750 level, while carbon dioxide (CO₂) reached 417.9 parts per million (ppm) in 2022, 150% of the 1750 level, and nitrous oxide (N₂O) reached 335.8 ppb, 124% of the 1750 level.

This image below shows some very high hourly average methane levels recently recorded at Barrow, Alaska.


The image below shows high monthly methane levels at Mauna Loa, Hawaii, U.S. 


The image below, created with a Copernicus forecast for November 15, 2023 03 UTC, shows very high methane levels over the Arctic at 500 hPa.



The image below shows that the NOAA-20 satellite recorded high methane levels over the Arctic Ocean, especially north of Alaska, on November 15, 2023 AM at 399.1 mb.

The image below shows methane levels as high as 2700 ppb recorded by the MetOp-B satellite on November 17, 2023 PM at 293 mb.


The image below shows high methane levels over Greenland recorded by the MetOp-B satellite on November 18, 2023 PM at 399 mb.


The image below shows mean methane levels of 1942 ppb recorded by the MetOp-B satellite on November 19, 2023 PM at 399 mb.


The Argo Float 6904087 compilation image below illustrates that the highest water temperatures in the Arctic Ocean can occur at a depth of about 250 meters.

[ click on images to enlarge ]
The Argo Float 6901934 compilation image below illustrates that the highest water temperatures in the Arctic Ocean can occur at a depth of about 250 meters.

[ click on images to enlarge ]
Arctic Ocean surface temperatures are strongly influenced by air temperatures and seasons, ranging from more than 10°C to as low as -1.8°C when there is sea ice.

[ from earlier post ]
By contrast, the water temperature below the surface can remain stable throughout the year at close to 0°C all the way down to 2000 meters without freezing, due to higher salinity. However, the water temperature can be well above 0°C throughout the year at a depth of a few hundred meters, which is worrying since much of the water is less than 200 m deep where the continental shelves extend into the Arctic Ocean (light blue map on the right) and methane hydrates at the seafloor there could instantly be destabilized by a sudden influx of warm water from the North Atlantic. 

Over the next few months, as sea ice keeps growing in extent, this seals off the Arctic Ocean from the atmosphere. This makes it harder for heat to get transferred from the Arctic Ocean to the atmosphere and increases the danger that more heat will reach sediments located at the seafloor and cause methane to be released from hydrates as well as methane that is present in the form of free gas underneath the hydrates.

The danger is illustrated by the image below, adapted from Climate Reanalyzer, which shows a rise in temperature (2 m) by 2100 compared to 1852-1900 using a CMIP6 SSP585 model. 


[ image from the Extinction page ]
Note that none of the bases used in the above images is pre-industrial, neither 1880-1920, nor 1951-1980, nor 1852-1900. Using a base that is genuinely pre-industrial base would result in even higher anomalies. The image on the right shows a 2.29°C 2020 anomaly from 3480 BC.  

Note also that even a small temperature rise (of less than 1°C) can destabilize a vulnerable methane hydrate, which can cause an eruption that in turn can destabilize neighbouring hydrates, resulting in a self-reinforcing feedback loop of methane releases, including methane in the form of free gas from underneath the hydrates. This can drive up temperatures very rapidly. 

Seafloor methane is only one out of many elements that could jointly cause a temperature rise of over 10°C within a few years, in the process causing the clouds tipping point to get crossed that can push up the temperature rise by a further 8°C, as illustrated by the image on the right, from the extinction page.

Conclusion

The precautionary principle calls for comprehensive and effective action to reduce the damage and to improve the situation, along the lines of this 2022 post in combination with a declaration of a climate emergency.


Links

• Climate Reanalyzer
https://climatereanalyzer.org/research_tools/monthly_maps

• NASA Temperature anomaly October 2023

• WMO Greenhouse Gas Bulletin No. 19 – 15 November 2023

• Copernicus - Methane forecasts





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