Friday, August 8, 2014

The Arctic Methane Monster's Rapid Rise


Researcher Jennifer Hynes recently gave a frightening presentation about the situation in the Arctic and the odds that things will rapidly spiral out of control soon, escalating into runaway global warming a few decades from now. 




Above, a slide from the presentation, warning about the danger of earthquakes causing methane hydrate destabilization (from: Smoke Blankets North America). As the map below shows, 77 M4+ earthquakes did hit locations around Greenland in the year 2014 up until August 4.


Below is Jennifer's presentation, also on youtube at youtube.com/watch?v=a9PshoYtoxo



The image below shows sea surface temperature anomalies in the Arctic at August 7, 2014.


Warm water is carried into the Arctic Ocean by the Gulf Stream, as illustrated by the image below.
[ click on image to enlarge ]
The image shows how the Gulf Stream brings warm water to the edge of the sea ice. Waters close to Svalbard reached temperatures as high as 15.6°C (60.1°F) on August 8, 2014 (green circle). Note that what the image shows are sea surface temperatures only. At greater depths (say 300 m), warm water is pushed through the Greenland Sea by the Gulf Stream. Since the passage west of Svalbard is rather shallow, a lot of this warm water comes to the surface there. The high sea surface temperatures west of Svalbard thus indicate that the Gulf Stream is carrying very warm water (warmer than 15°C) at greater depths and is pushing this underneath the sea ice north of Svalbard.

As said, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog at climateplan.blogspot.com and as illustrated by the image below.



Monday, August 4, 2014

Warm waters threaten to trigger huge methane eruptions from Arctic Ocean seafloor

The evidence of abrupt high methane releases in the Arctic Ocean is accumulating. The graph below shows in situ methane measurements taken at the Barrow Observatory, including recent levels as high as close to 2200 parts per billion (ppb).


Satellite data picture a similarly dire situation. Global mean methane levels as high as 1831 ppb were recorded on the morning of July 30, 2014, while peak methane levels as high as 2330 ppb were recorded that morning. More recently, peak methane levels as high as 2522 ppb were recorded (on August 2, 2014).

IPCC/NOAA figures suggest that methane levels were rising by some 5 to 6 ppb annually, reaching 1814 ppb in 2013. While methane levels at lower altitudes have indeed shown little rise, much larger rises have been recorded at higher altitudes, as illustrated by the image below.


These high methane levels recorded at higher altitudes appear to be caused by the huge quantities of methane released from the seafloor of the Arctic Ocean during the period from end 2013 to early 2014. This methane has meanwhile risen to higher altitudes, while also descending to lower latitudes, wreaking havoc on weather patterns around latitude 60° North.

The releases of methane from the seafloor of the Arctic Ocean were caused by water that had warmed up strongly off the east coast of North America from June 2013. It took some months for this warm water to be carried by the Gulf Stream into the Arctic Ocean.


Meanwhile, very high sea surface temperatures are recorded in the Arctic Ocean, as above image shows, while warm water is carried into the Arctic Ocean by the Gulf Stream, as illustrated by the image below.


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




Tuesday, July 29, 2014

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



Monday, July 21, 2014

Methane rising through fractures

by Harold Hensel



Methane is colorless and odorless and it is right above us in the atmosphere.

In addition to other sources, methane has traveled from the Arctic and has blanketed most of the Northern Hemisphere.

The well-known sources are methane hydrates from the Arctic Ocean floor and methane coming from thawing permafrost.

There is also another less well-known source. During the geologic history of the Arctic area, tectonic plates have spread, crashed into each other and subducted under one another. Geologists call the Arctic a tectonic plate junkyard. There are numerous fractures in the earth's crust there.

A quote from earth scientist Malcolm Light: ‘Mantle methane formed from the reduction of oceanic carbonates by water in the presence of iron (II) oxides buried to depths of 100 km to 300 km in the Asthenosphere and at temperatures above 1200°C.’ This is a nonorganic source of methane formed near the earth's mantel. Katey Walter Anthony from the University of Alaska calls it geologic methane.

Vast reservoirs of methane have been created by chemical reactions and stored near the mantle under a lot of pressure for millennia.

The methane has had a route to the surface through the fractures in the earth's crust, but the fractures have been sealed over by ice. Now for the first time in human history, the ice sealing the fractures is thawing. Methane is rising through the fractures and into the atmo­sphere. This methane has migrated to the United States and is over us.




Harold Hensel, 
Cedar Rapids.
Earlier published as 
Letter to the Editor 
Cedar Rapids Gazette 
(without images)


Related

- Study: Geologic methane seeping from thawing cryosphere - by Marmian Grimes
http://uafcornerstone.net/study-geologic-methane-seeping-from-thawing-cryosphere

- Focus on Methane - by Malcolm Light
http://arctic-news.blogspot.com/2014/07/focus-on-methane.html

- Arctic Atmospheric Methane Global Warming Veil - by Malcolm Light, Harold Hensel and Sam Carana

- Mantle Methane - by Malcolm Light