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.


- South Greenland ice-sheet collapse during Marine Isotope Stage 11, Reyes et al. (2014)

- Nonsustainable groundwater sustaining irrigation: A global assessment, Yoshihide Wada et al. (2012)

- Groundwater Depletion Linked to Rising Sea Levels

- 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)

- Feedbacks in the Arctic

- How many deaths could result from failure to act on climate change? (2014)

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)


- Study: Geologic methane seeping from thawing cryosphere - by Marmian Grimes

- Focus on Methane - by Malcolm Light

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

- Mantle Methane - by Malcolm Light

Friday, July 18, 2014

Smoke Blankets North America

A thick layer of smoke blankets large parts of North America, as also illustrated by the animation below based on images from July 15 to 18, 2014, from Wunderground.com.

[ note that this animation is a 2.3MB file that may take some time to fully load ]
The are also extensive wildfires throughout the boreal forest and tundra zones of Central Siberia in Russia.

Such wildfires can send huge amounts of carbon dioxide, methane, soot, dust and volatile organic compounds into the atmosphere. Much of this gets deposited at higher latitudes, discoloring land, snow and ice, and thus speeding up warming by absorbing more sunlight that was previously reflected back into space.

Soils at higher latitudes can contain huge amounts of carbon in the form of peat, as described in the earlier post The Threat of Wildfires in the North. There are further conditions that make the situation in the Arctic so dangerous.
Temperature anomaly March-April-May-June 2014 (JMA)

The Arctic is particularly vulnerable to warming due to geographics. Seas in the Arctic Ocean are often shallow and covered by sea ice that is disappearing rapidly. Largely surrounded by land that is also rapidly losing its snow and ice cover, the Arctic Ocean acts like a trap capturing heat carried in by the Gulf Stream, which brings in ever warmer water. Of all the heat trapped on Earth by greenhouse gases, 90% goes into oceans, while a large part of the remaining 10% goes into melting the snow and ice cover in the Arctic, as described in an earlier post. Such basic conditions make that the Arctic is prone to warming.

Then, there are huge amounts of methane held in sediments under the Arctic Ocean, in the form of hydrates and free gas. Unlike methane releases from biological sources elsewhere on Earth, methane can be released from the seafloor of the Arctic Ocean in large quantities, in sudden eruptions that are concentrated in one area.

Until now, permafrost and the sea ice have acted as a seal, preventing heat from penetrating these methane hydrates and causing further destabilization. As long as there is ice, additional energy will go into melting the ice, and temperatures will not rise. The ice also acts as a glue, keeping the soil together and preventing hydrate destabilization from pressure changes and shockwaves resulting from seismic activity. Once the ice is gone, sediments become prone to destabilization and heat can more easily move down along fractures in the sediment, reaching hydrates that had until then remained stable.
Temperature anomaly March-April-May 2014 (NASA)
When methane escapes from the seafloor of the Arctic Ocean and travels through waters that are only shallow, there is little opportunity for this methane to be broken down in the water, so a lot of it will enter the atmosphere over the Arctic Ocean. The Coriolis effect will spread the methane sideways, but latitudes over the Arctic are relatively short, making the methane return at the same spot relatively quickly, while the polar jet stream acts as a barrier keeping much of the methane within the Arctic atmosphere. In case of large methane eruptions, the atmosphere over the Arctic will quickly become supersaturated with methane that has a huge initial local warming potential.

Hydroxyl levels in the atmosphere over the Arctic are very low, extending the lifetime of methane and other precursors of stratospheric ozone and water vapor, each of which have a strong short-term local warming potential. In June/July, insolation in the Arctic is higher than anywhere else on Earth, with the potential to quickly warm up shallow waters, making that heat can penetrate deep into sediments under the seafloor.

created by Sam Carana, part of AGU 2011 poster
The initial impact of this methane will be felt most severely in the Arctic itself, given the concentrated and abrupt nature of such releases, with the danger that even relatively small releases of methane from the seafloor of the Arctic can trigger further destabilization of hydrates and further methane releases, escalating into runaway warming.

This danger is depicted in the image on the right, showing how albedo changes and methane releases act as feedbacks that further accelerate warming in the Arctic, eventually spiraling into runaway global warming.

The currently very high sea surface temperature anomalies are illustrated by the two images below.

As the image below right shows, sea surface temperatures as high as 18 degrees Celsius (64.4 degrees Fahrenheit) are currently recorded in the Arctic.

Albedo changes and methane releases are only two out of numerous feedbacks that are accelerating warming in the Arctic.

Also included must be the fact that Earth is in a state of energy imbalance. Earth is receiving more heat from sunlight than it is emitting back into space. Over the past 50 years, the oceans have absorbed about 90% of the total heat added to the climate system, while the rest goes to melting sea and land ice, warming the land surface and warming and moistening the atmosphere.

In a 2005 paper, James Hansen et al. estimated that it would take 25 to 50 years for Earth’s surface temperature to reach 60% of its equilibrium response, in case there would be no further change of atmospheric composition. The authors added that the delay could be as short as ten years.

Earth's waters act as a buffer, delaying the rise in land surface temperatures that would otherwise occur, but this delay could be shortened. Much of that extra ocean heat may enter the atmosphere much sooner, e.g. as part of an El Niño event. Another buffer, Arctic sea ice, could collapse within years, as illustrated by the image below.

[ click on image to enlarge ]
The demise of sea ice comes with huge albedo changes, resulting in more heat getting absorbed by the Arctic Ocean, in turn speeding up warming of the often shallow waters of the Arctic Ocean. This threatens to make heat penetrate subsea sediments containing huge amounts of methane. Abrupt release of large amounts of methane would warm up the Arctic even more, triggering even further methane releases in a spiral of runaway warming.

Particularly worrying is the currently very warm water that is penetrating the Arctic Ocean from the Atlantic Ocean and also from the Pacific Ocean, as illustrated by the image further above and the image on the right.

The danger is that the Arctic will warm rapidly with decline of the snow and ice cover that until now has acted as a buffer absorbing heat, with more sunlight gets absorbed due to albedo changes and as with additional emissions, particularly methane, resulting from accelerating warming in the Arctic.

The numerous feedbacks that accelerate warming in the Arctic are pictured in the image below.

[ from: climateplan.blogspot.com/p/feedbacks.html ]
Furthermore, the necessary shift to clean energy will also remove the current masking effect of aerosols emitted when burning fuel. One study finds that a 35% – 80% cut in people's emission of aerosols and their precursors will result in about 1°C of additional global warming.

In the video below and the video further down below, Guy McPherson discusses Climate Change and Human Extinction.

This is further illustrated by the image below, showing how surface temperature rises are accelerating in the Arctic compared to global rises, with trendlines added including one for runaway global warming, from How many deaths could result from failure to act on climate change?
[ click on image to enlarge ]
The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.

Hat tip to Jim Kirkcaldy for pointing at the wildfire development at an early stage.

Monday, July 14, 2014

Focus on Methane

by Malcolm Light

Methane formed by organisms in the water becomes trapped in the fabric of water ice crystals when it freezes and is stable below about 300 metres depth in the Arctic Ocean.

There are such massive methane reserves below the Arctic Ocean floor that they represent around 100 times the amount that is required to cause a Permian style major extinction event, should the methane be released into the atmosphere.

There are also giant reservoirs of mantle methane, originally sealed in by shallow methane hydrate plugs in fractures cutting the Arctic seafloor.

Unfortunately for us, global warming has heated up the oceanic currents fed by the Gulf Stream flowing into the Arctic, causing massive destabilization of the subsea methane hydrates and fault seals and releasing increasing volumes of methane directly into the atmosphere.

Screenshot from Perdue University's Vulcan animation, which
shows pollution from North America spreading over the North
Atlantic, from Warming of the Arctic Fueling Extreme Weather
The volume transport of the Gulf Stream has increased by three times since the 1940s due to the rising atmospheric pressure difference set up between the polluted, greenhouse gas rich air above North America and the marine Atlantic air.

The increasingly heated Gulf Stream, with its associated high winds and energy rich weather systems, flows NE to Europe where it recently pummelled Great Britain with catastrophic storms. Other branches of the Gulf Stream then enter the Arctic and heat up the Arctic methane hydrate seals on subsea and deep high - pressure mantle methane reservoirs below the Eurasian Basin- Laptev Sea transition.

This is releasing increasing amounts of methane into the atmosphere contributing to anomalous temperatures, greater than 20 degree C above average. Over very short time periods of a few days to a few months the atmospheric methane has a warming potential from 1000 to 100 times that of carbon dioxide.

The amount of carbon stored in hydrates globally
was in 1992 estimated to be 10,000 Gt (USGS),
while a later source gives a figure of 63,400 Gt C
for the Klauda & Sandler (2005) estimate of marine
hydrates. A warming Gulf Stream causes methane
 off the North American coast. Methane also
appears to be erupting from hydrates on Antarctica,
on the Qinghai-Tibetan Plateau and on Greenland.
In just one part of the Arctic Ocean alone, the East
Siberian Arctic Shelf (ESAS), up to 1700 Gt of
methane is contained in sediments in the form of
methane hydrates and free gas. A sudden release
of just 3% of this amount could add over 50 Gt of
methane to the atmosphere, i.e. some seven times
what is in the atmosphere now, and experts consider
such an amount to be ready for release at any time.
From: Will the Anthropocene last for only 100 years?
There are such massive reserves of methane in the subsea Arctic methane hydrates, that if only a few percent of them are released, they will lead to a jump in the average temperature of the Earth's atmosphere of 10 degrees C and produce a "Permian" style major extinction event which will kill us all.

The whole northern hemisphere is now covered by a thickening atmospheric methane veil that is spreading southwards at about 1 km a day and it already totally envelopes the United States.

A giant hole in the equatorial ozone layer has also been discovered in the west Pacific, which acts like an elevator transferring methane from lower altitudes to the stratosphere, where it already forms a dense equatorial global warming stratospheric band that is spreading into the Polar regions.

The spreading atmospheric methane global warming veil is raising the temperature of the lower atmosphere many times faster than carbon dioxide does, causing the extreme summer temperatures in Australia and the US.

During the last winter, the high Arctic winter temperatures and pressures displaced the normal freezing Arctic air south into Canada and the United States, producing never before seen, freezing winter storms and massive power failures.

When the Arctic ice cap finally melts towards the end of next year, the Arctic sea will be aggressively heated by the sun and the Gulf Stream. The cold Arctic air will then be confined to the Greenland Ice cap and the hot Arctic air with its methane will flow south to the United States to further heat up the Gulf Stream, setting up an anticlockwise circulation around Greenland.

Under these circumstances Great Britain and Europe must expect even more catastrophic storm systems, hurricane force winds and massive flooding after the end of next year, due to a further acceleration in the energy transport of the Gulf Stream. If this process continues unchecked the mean temperature of the atmosphere will rise a further 8 degrees centigrade and we will be facing global deglaciation, a more than 200 feet rise in sea level rise and a major terminal extinction event by the 2050s.

The US and Canada must cut their global emissions of carbon dioxide by 90% in the next 10 to 15 years, otherwise they will be become an instrument of mass destruction of the Earth and its entire human population. Recovery of the United States economy from the financial crisis has been very unsoundly based by the present administration on an extremely hazardous "all of the above" energy policy that has allowed continent wide gas fracking, coal and oil sand mining and the return of widespread drilling to the Gulf Coast. This large amount of fossil fuel has to be transported and sold which has caused extensive spills, explosions and confrontations with US citizens over fracking and the Keystone XL pipeline. Gas fracking is in the process of destroying the entire aquifer systems of the United States and causing widespread earthquakes. The oil spills are doing the same to the surface river run off.

We are now facing a devastating final show down with Mother Nature, which is being massively accelerated by the filthy extraction of fossil fuels by US and Canada by gas fracking, coal and tar sand mining and continent wide bitumen transport. The United States and other developed nations made a fatal mistake by refusing to sign the original Kyoto protocols. The United States and Canada must now cease all their fossil fuel extraction and go entirely onto renewable energy in the next 10 to 15 years otherwise they will be guilty of planetary ecocide - genocide by the 2050's. There must also be a world-wide effort to capture methane in the oceans and eradicate the quantities accumulating in the atmosphere.