The Methane Threat

Carbon dioxide levels in the atmosphere are accelerating. As illustrated by the image below, a linear trend hardly catches the acceleration, while a polynomial trend does make a better fit. The polynomial trend points at CO₂ levels of 437 ppm by 2026.

EPA animation: more extreme heat

This worrying acceleration is taking place while energy-related have been virtually flat over the past few years, according to figures by the EIA and by the Global Carbon Project. So, what makes growth in CO₂ levels in the atmosphere accelerate? As earlier discussed in this and this post, growth in CO₂ levels in the atmosphere is accelerating due to continued deforestation and soil degradation, due to ever more extreme weather events and due to accelerating warming that is making oceans unable to further take up carbon dioxide.

Ocean warming is accelerating on the Northern Hemisphere, as illustrated by above image, and a warmer Atlantic Ocean will push ever warmer water into the Arctic Ocean, further speeding up the decline of the sea ice and of permafrost.

[ click on images to enlarge ]

Loss of Northern Hemisphere snow cover is alarming, especially in July, as depicted in above image. The panel on the left shows snow cover on the Northern Hemisphere in three areas, i.e. Greenland, North America and Eurasia. The center panel shows North America and the right panel shows Eurasia. While Greenland is losing huge amounts of ice from melting glaciers, a lot of snow cover still remains present on Greenland, unlike the permafrost in North America and especially Eurasia, which has all but disappeared in July.

[ for original image, see 2011 AGU poster ]

Worryingly, the linear trend in the right panel points at zero snow cover in 2017, which should act as a warning that climate change could strike a lot faster than many may expect.

A recently-published study warns that permafrost loss is likely to be 4 million km² (about 1.5 million mi²) for each 1°C (1.8°F) temperature rise, about 20% higher than previous studies. Temperatures may well rise even faster, due to numerous self-reinforcing feedback loops that speed up the changes and due to interaction between the individual warming elements behind the changes.

[ Arctic sea ice, gone by Sept. 2017? ]

One of the feedbacks is albedo loss that speeds up warming in the Arctic, in turn making permafrost release greenhouse gases such as carbon dioxide, nitrous oxide and methane.

Higher temperatures on land will make warmer water from rivers enter the Arctic Ocean and trigger wildfires resulting in huge emissions including black carbon that can settle on sea ice.

Given the speed at which many feedbacks and the interaction between warming elements can occur, Arctic sea ice volume may decline even more rapidly than the image on the right may suggest.

[ Record sea ice volume anomalies since end 2016 ]

Ominously, sea ice volume anomalies have been at record levels for time of year since end 2016 (Wipneus graph right, PIOMAS data).

As the Gulf Stream pushes warmer water into the Arctic Ocean, there will no longer be a large buffer of sea ice there to consume the heat, as was common for the entire human history.

Moreover, forecasts are that temperatures will keep rising throughout 2017 and beyond.

The Australian Bureau of Meteorology reports that seven of eight models indicate that sea surface temperatures will exceed El Niño thresholds during the second half of 2017.

The image on the right, by the ECMWF (European Centre for Medium-Range Weather Forecasts), indicates an El Niño that is gaining strength.

For more than half a year now, global sea ice extent has been way below what it used to be, meaning that a huge amount of sunlight that was previously reflected back into space, is now instead getting absorbed by Earth, as the graph below shows.

[ Graph by Wipneus ]

Where can all this extra heat go? Sea ice will start sealing off much of the surface of the Arctic Ocean by the end of September 2017, making it hard for more heat to escape from the Arctic Ocean by entering the atmosphere.

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

It looks like much of the extra heat will instead reach sediments at the seafloor of the Arctic Ocean that contain huge amounts of methane in currently still frozen hydrates.

[ click on image to enlarge ]

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

As the image on the right shows, a polynomial trend based on NOAA July 1983 to January 2017 global monthly mean methane data, points at twice as much methane by 2034. Stronger methane releases from the seafloor could make such a doubling occur much earlier.

Meanwhile, methane levels as high as 2592 ppb were recorded on April 17, 2017, as shown by the image below. The image doesn't specify the source of the high reading, but the magenta-colored area over the East Siberian Sea (top right) looks very threatening.

We already are in the Sixth Mass Extinction Event, given the rate at which species are currently disappearing from Earth. When taking into account the many elements that are contributing to warming, a potential warming of 10°C (18°F) could take place, leading to a rapid mass extinction of many species, including humans.

[ Graph from: Which Trend is Best? ]

How long could it take for such warming to eventuate? As above image illustrates, it could happen as fast as within the next four years time.

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


Links

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

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

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Accelerating growth in CO₂ levels in the atmosphere
https://arctic-news.blogspot.com/2017/02/accelerating-growth-in-co2-levels-in-the-atmosphere.html

• An observation-based constraint on permafrost loss as a function of global warming, by Chadburn et al. (2017)
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3262.html

• Reduction of forest soil respiration in response to nitrogen deposition, by Janssens et al. (2010)
http://www.nature.com/ngeo/journal/v3/n5/full/ngeo844.html

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

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

Arctic Sea Ice Collapse Threatens - Update 3

The image below is based on a nullschool.net forecast for August 6, 2015, run on August 2, 2015. It shows temperatures as high as 26.4°C (or 79.4°F) in the north of Canada (green circle). The inset, based on a Climate Reanalyzer forecast for that date, shows that this is as much as 20°C (or 36°F) higher than temperatures that were common in the area only recently, i.e. from 1979-2000.

The satellite image below, captured on August 2, 2015, shows a close-up of the area, with the green circle in the same location as on above image.

Above image shows that there still is some solid ice present to the right of the green circle. This ice may not be able to survive such high temperatures for long. Furthermore, above image shows what looks like smoke plumes from wildfires to the left of the green circle, another sign of the high temperatures in the area and another feedback that will accelerate decline of the snow and ice cover.

Disappearance of sea ice thicker than 4 meters is now taking place north of Canada and Greenland. It looks set to virtually disappear soon, as shown by the 30-day Naval Research Laboratory animation below, ending with a forecast up to August 10, 2015.

In my experience, sea ice thickness hasn't looked this bad for this time of the year since records began, especially when taking the loss of multi-year ice into account. Until now, the thicker multi-year sea ice used to survive the melting season, giving the sea ice strength for the next year, by acting as a buffer to absorb heat that would otherwise melt away the thinner ice. Without multi-year sea ice, the Arctic will be in a bad shape in coming years. Absence of thick sea ice makes it more prone to collapse, and this raises the question whether a collapse could occur not merely some years from now, but even this year.

Above image below shows sea surface temperature anomalies in the Arctic on August 2, 2015.

Greenland's dramatic loss of ice mass over the past few years and the subsequent meltwater may have caused the sea ice to be larger than it would otherwise have been.

Nonetheless, this has not halted the overall decline of the sea ice. As the image on the right shows, sea ice area now is about as low for the time of the year as it was for the three lowest years on record. Furthermore, thick sea ice is shattered if not gone altogether in many places. Meanwhile, ocean heat is at a record high and there's an El Nino that's still gaining strength.

In conclusion, Arctic sea ice looks set to take a further battering over the next few weeks and could end up at a record low around half September 2015. If things get really bad, sea ice collapse could occur and the remaining pieces of sea ice could be driven out of the Arctic Ocean altogether by storms, resulting in a blue ocean event as early as September this year.

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

Arctic sea ice area on July 31, 2015.
Posted by Sam Carana on Sunday, August 2, 2015

Arctic Sea Ice Collapse Threatens - Update 1

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 compares the Arctic sea ice concentration (in %) on July 18, for the years from 2012 (left panel) to 2015 (right panel), using Naval Research Laboratory images.

Above images show the dramatic decline of the sea ice in 2015, both in thickness and in concentration.

In terms of thickness, sea ice has been reduced by more than one meter in many places, such as north of Greenland and the Canadian Archipelago, all in the time span of just one month.

The dramatic fall in sea ice concentration also becomes apparent when comparing recent sea ice concentration (July 18, 2015, above right) with sea ice concentration back in May 2015 (image right, May 1, 2015).

This dramatic decline of the sea ice in 2015 is the result of a combination of factors, including:

1. High levels of greenhouse gases over the Arctic Ocean, as illustrated by the image below, showing that on July 17, 2015 (pm), levels as high as 2512 parts per billion were recorded at 6,041 m (19,820 ft) altitude, while mean methane levels were 1830 parts per billion at this altitude.
   
2. High levels of ocean heat, as illustrated by the image below showing high sea surface temperatures off the east coast of North America; much of this ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months.
   
3. High air temperatures over North America and Siberia extending over the Arctic Ocean, as illustrated by the image below showing a temperature of 23.1°C (73.7°F), recorded on July 19, 2015, at Banks Island, in the Canadian Archipelago (green circle).
   
4. Wildfires triggered by these heatwaves resulting in darkening compounds settling on snow and ice, as illustrated by the image below showing smoke covering a wide area on July 19, 2015, from the east Siberia over North America to the southern tip of Greenland.
   
5. Very warm river water running into the Arctic Ocean, as illustrated by the image below, showing sea surface temperatures as high as 19°C (66.2°F) off the coast of Alaska on July 12-15, 2015.
   

The image below shows the already very high sea surface temperature anomalies as at July 18, 2015.

The Climate Reanalyzer image below shows the high sea surface temperature anomalies in the Pacific Ocean, and where water enter the Arctic Ocean through the Bering Strait, on July 19, 2015.

With still two months of melting to go before the sea ice can be expected to reach its minimum for 2015, the threat of sea ice collapse is ominous. The Arctic-News Blog has been warning for years about the growing chance of a collapse of the sea ice, in which case huge amounts of sunlight that previously were reflected back into space, as well as heat that previously went into melting the ice, will then instead have to be absorbed by the water, resulting in a dramatic rise of sea surface temperatures.

More open water will then come with an increased chance of storms that can cause high sea surface temperatures to be mixed down all the way to seafloor of the Arctic Ocean, which in many cases is less than 50 m (164 ft) deep. This is the case for the East Siberian Arctic Shelf, where experts estimate that huge amounts of methane are contained in subsea sediments. Already now, sea surface temperatures as high as 10°C (~50°F) are recorded there, as illustrated by the image below.

Massive amounts of ocean heat will be carried by the Gulf Stream into the Arctic Ocean over the next few months. The combined result of high sea surface temperatures being mixed down to the seafloor and the ocean heat entering the Arctic Ocean from the Atlantic and Pacific Oceans can be expected to result in dramatic methane eruptions from the Arctic Ocean seafloor by October 2015.

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

Arctic sea ice thickness on July 15, compared over the years 2012 through to 2015. Already virtually all the thick sea...

Posted by Sam Carana on Thursday, July 16, 2015