Posts tagged methane

Melting Permafrost

 

The subject of methane hydrates has yet again been featured in the BBC news.  The BBC news has featured stories about the possible deleterious effects of the melting permafrost since at least 2005. *see below.  Research has been in progress on the subject for many years *see below, yet the 4th Assessment of the IPCC does not mention methane hydrates or methane clathrates.  The nearest they get is to mention that the permafrost is melting:

 

“Snow cover is projected to contract. Widespread increases in thaw depth are projected over most

permafrost regions.” {10.3, 10.6}  pg.12

 

Climate Change 2007: The Physical Science Basis

Summary for Policymakers

Contribution of Working Group I to the Fourth Assessment Report of the

Intergovernmental Panel on Climate Change

 

 

It is generally known and not controversial that as the permafrost melts, methane is released.  It was well known well before 2007 that there are vast amounts of methane locked up in clathrates.

 

“Recent estimates constrained by direct sampling suggest the global inventory occupies between one and five million cubic kilometres (0.24 to 1.2 million cubic miles).[19] This estimate, corresponding to 500-2500 gigatonnes carbon (Gt C), is smaller than the 5000 Gt C estimated for all other fossil fuel reserves but substantially larger than the ~230 Gt C estimated for other natural gas sources.[19][21] The permafrost reservoir has been estimated at about 400 Gt C in the Arctic,[22][citation needed] but no estimates have been made of possible Antarctic reservoirs. These are large amounts, for comparison the total carbon in the atmosphere is around 700 gigatons.[23]  ^ Geotimes — November 2004 — Methane Hydrate and Abrupt Climate Change

http://en.wikipedia.org/wiki/Methane_clathrate

 

So, why was it not even mentioned in the IPCC Assessment?

 

 

 

 

 

References:

 

Methane hydrate — A major reservoir of carbon in the shallow geosphere?

Keith A. Kvenvolden

U.S. Geological Survey, Menlo Park, CA 94025 U.S.A. [1988]

http://pubs.er.usgs.gov/publication/70013975

 

 

 

“The world’s largest frozen peat bog is melting, which could speed the rate of global warming, New Scientist reports.”  [2005]    http://www.bbc.co.uk/news/science-environment-21549643

 

“Scientists drilling ocean sediments off Canada have discovered methane ices at much shallower depths than expected. The finding has important implications for climate studies, they believe.” [2006]

 

“Methane bubbles observed by sonar, escape from sea-bed as temperatures rise. Scientists say they have evidence that the powerful greenhouse gas methane is escaping from the Arctic sea-bed.”  [2009]

 

“Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.”  [2010]

 

Evidence from Siberian caves suggests that a global temperature rise of 1.5C could see permafrost thaw over a large area of Siberia. “A study shows that more than a trillion tonnes of the greenhouse gases CO2 and methane could be released into the atmosphere as a result.”   [2013]  http://www.bbc.co.uk/news/science-environment-21549643

 

 

 

 

 

 

 

 

 

 

 

 

Methane release ‘looks stronger’  [2010]

By Michael Fitzpatrick

Science reporter, BBC News

 

Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.

 

Methane is about 20 times more potent than CO2 in trapping solar heat.

 

The findings come from measurements of carbon fluxes around the north of Russia, led by Igor Semiletov from the University of Alaska at Fairbanks.

 

“Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be],” he said.

 

Professor Semiletov has been studying methane seepage in the region for the last few decades, and leads the International Siberian Shelf Study (ISSS), which has launched multiple expeditions to the Arctic Ocean.

 

The preliminary findings of ISSS 2009 are now being prepared for publication, he told BBC News.

 

Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.

 

High seepage

 

Acting as a giant frozen depository of carbon such as CO2 and methane (often stored as compacted solid gas hydrates), Siberia’s shallow shelf areas are increasingly subjected to warming and are now giving up greater amounts of methane to the sea and to the atmosphere than recorded in the past.

 

METHANE HYDRATES

Methane gas is trapped inside a crystal structure of water-ice

The gas is released when the ice melts, normally at 0C

At higher pressure, ie under the ocean, hydrates are stable at higher temperatures

This undersea permafrost was until recently considered to be stable.

 

But now scientists think the release of such a powerful greenhouse gas may accelerate global warming.

 

Higher concentrations of atmospheric methane are contributing to global temperature rise; this in turn is projected to cause further permafrost melting and the release of yet more methane in a feedback loop.

 

A worst-case scenario is one where the feedback passes a tipping point and billions of tonnes of methane are released suddenly, as has occurred at least once in the Earth’s past.

 

Such sudden releases have been linked to rapid increases in global temperatures and could have been a factor in the mass extinction of species.

 

According to a report by the US National Oceanic and Atmospheric Administration (Noaa), the springtime air temperature across the region in the period 2000-2007 was an average of 4C higher than during 1970-199

 

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/8437703.stm

 

Published: 2010/01/06 17:17:31 GMT

 

© BBC 2013ttp://news.bbc.co.uk/1/hi/sci/tech/8437703.stm

 

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Siberia’s rapid thaw causes alarm [2005]

 

The world’s largest frozen peat bog is melting, which could speed the rate of global warming, New Scientist reports.

The huge expanse of western Siberia is thawing for the first time since its formation, 11,000 years ago.

 

Sky:  It was NOT formed 11,000 years ago.

 

 

The area, which is the size of France and Germany combined, could release billions of tonnes of greenhouse gases into the atmosphere.

 

This could potentially act as a tipping point, causing global warming to snowball, scientists fear.

 

The situation is an “ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming,” researcher Sergei Kirpotin, of Tomsk State University, Russia, told New Scientist magazine.

 

The whole western Siberian sub-Arctic region has started to thaw, he added, and this “has all happened in the last three or four years”.

 

Warming fast

 

Western Siberia has warmed faster than almost anywhere on the planet, with average temperatures increasing by about 3C in the last 40 years.

 

The warming is believed to be due to a combination of man-made climate change, a cyclical atmospheric phenomenon known as the Arctic oscillation and feedbacks caused by melting ice.

 

“ When you start messing around with these natural systems, you can end up in situations where it’s unstoppable ”

David Viner, climate scientist

The 11,000-year-old bogs contain billions of tonnes of methane, most of which has been trapped in permafrost and deeper ice-like structures called clathrates.

But if the bogs melt, there is a big risk their hefty methane load could be dumped into the atmosphere, accelerating global warming.

 

Scientists have reacted with alarm at the finding, warning that future global temperature predictions may have to be revised.

 

“When you start messing around with these natural systems, you can end up in situations where it’s unstoppable,” David Viner, of the University of East Anglia, UK, told the Guardian newspaper. “There are no brakes you can apply.

 

“This is a big deal because you can’t put the permafrost back once it’s gone. The causal effect is human activity and it will ramp up temperatures even more than our emissions are doing.”

 

The intergovernmental panel on climate change speculated in 2001 that global temperatures would rise between 1.4C and 5.8C between 1990 and 2100.

 

However these estimates only considered global warming sparked by known greenhouse gas emissions.

 

“These positive feedbacks with landmasses weren’t known about then,” Dr Viner said. “They had no idea how much they would add to global warming.”

 

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/4141348.stm

 

Published: 2005/08/11 10:46:46 GMT

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Methane seeps from Arctic sea-bed  [2009]

 

By Judith Burns

Science and environment reporter, BBC News

Tuesday, 18 August 2009 13:47 UK

http://news.bbc.co.uk/1/hi/sci/tech/8205864.stm

 

 

Methane bubbles observed by sonar, escape from sea-bed as temperatures rise

 

Scientists say they have evidence that the powerful greenhouse gas methane is escaping from the Arctic sea-bed.

Researchers say this could be evidence of a predicted positive feedback effect of climate change.

As temperatures rise, the sea-bed grows warmer and frozen water crystals in the sediment break down, allowing methane trapped inside them to escape.

The research team found that more than 250 plumes of methane bubbles are rising from the sea-bed off Norway.

The joint British and German research team detected the bubbles using a type of sonar normally used to search for shoals of fish. Once detected, the bubbles were sampled and tested for methane at a range of depths.

Writing in Geophysical Research Letters, the team says the methane was rising from an area of sea-bed off West Spitsbergen, from depths between 150m and 400m.

The gas is normally trapped as “methane hydrate” in sediment under the ocean floor.

METHANE HYDRATES

Methane gas is trapped inside a crystal structure of water-ice

The gas is released when the ice melts, normally at 0C

At higher pressure, ie under the ocean, hydrates are stable at higher temperatures

“Methane hydrate” is an ice-like substance composed of water and methane which is stable under conditions of high pressure and low temperature.

As temperatures rise, the hydrate breaks down. So this new evidence shows that methane is stable at water depths greater than 400m off Spitsbergen.

However, data collected over 30 years shows it was then stable at water depths as shallow as 360m.

Ocean has warmed

Temperature records show that this area of the ocean has warmed by 1C during the same period.

The research was carried out as part of the International Polar Year Initiative, funded by Britain’s Natural Environment Research Council (Nerc).

The team says this is the first time that this loss of stability associated with temperature rise has been observed during the current geological period.

Professor Tim Minshull of the National Oceanography Centre at Southampton told BBC News: “We already knew there was some methane hydrate in the ocean off Spitsbergen and that’s an area where climate change is happening rather faster than just about anywhere else in the world.”

 

1. Methane hydrate is stable below 400m

2. Nearer the surface the hydrate breaks down as temperatures rise and the methane is released

3. Gas rises from the sea-bed in plumes of bubbles – most of it dissolves before it reaches the surface

4. So far scientists haven’t detected methane breaking the ocean surface – but they don’t rule out the possibility

 

“There’s been an idea for a long time that if the oceans warm, methane might be released from hydrate beneath the sea floor and generate a positive greenhouse effect.

“What we’re trying to do is to use lots of different techniques to assess whether this was something that was likely to happen in a relatively short time scale off Spitsbergen.”

However, methane is already released from ocean floor hydrates at higher temperatures and lower pressures – so the team also suggests that some methane release may have been going on in this area since the last ice age.

Significant discovery

Their most significant finding is that climate change means the gas is being released from more and deeper areas of the Arctic Ocean.

Professor Minshull said: “Our survey was designed to work out how much methane might be released by future ocean warming; we did not expect to discover such strong evidence that this process has already started.”

“We were slightly surprised that if there was so much methane rising why no one had seen it before. But I think the reason is that you have to be rather dedicated to spot it because these plumes are only perhaps 50m to 100m across.

“The device we were using is only switched on during biological cruises. It’s not normally used on geophysical or oceanographic cruises like ours. And of course you’ve got to monitor it 24 hours a day. In fact, we only spotted the phenomenon half way through our cruise. We decided to go back and take a closer look.”

The team found that most of the methane is being dissolved into the seawater and did not detect evidence of the gas breaking the surface of the ocean and getting into the atmosphere.

The researchers stress that this does not mean that the gas does not enter the atmosphere. They point out that the methane seeps are unpredictable and erratic in quantity, size and duration.

It is possible that larger seeps at different times and locations might in fact be vigorous enough to break through the ocean surface.

Most of the methane reacts with the oxygen in the water to form carbon dioxide, another greenhouse gas. In sea water, this forms carbonic acid which adds to ocean acidification, with consequent problems for biodiversity.

Graham Westbrook, lead author and professor of geophysics at the University of Birmingham, said: “If this process becomes widespread along Arctic continental margins, tens of megatonnes of methane a year – equivalent to 5-10% of the total amount released globally by natural sources, could be released into the ocean.”

The team is planning another expedition next year to observe the behaviour of the methane plumes over time. They are also engaged in ongoing research into the amount of methane hydrate under this area of the ocean floor.

Ultimately, they want to be able to predict how much might be vulnerable to temperature change and in what timescale.

 

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Methane ices pose climate puzzle [2006]

By Jonathan Amos

Science reporter, BBC News, San Francisco

 

“Scientists drilling ocean sediments off Canada have discovered methane ices at much shallower depths than expected. The finding has important implications for climate studies, they believe.”

 

The melting of hydrates, as they are known, is a suspected contributor to past and present increases in atmospheric methane, a greenhouse gas.

 

If shallow ices are destabilised in a warming world, it could have a positive feedback effect and drive temperatures even higher, the researchers warned.

 

“The rate of increase in the Earth’s atmosphere for methane is much faster than that for carbon dioxide,” said Timothy Collett, the co-chief scientist of the Integrated Ocean Drilling Program (IODP).

 

“Methane is 20 times more effective as a greenhouse gas than CO2. The source of this methane is uncertain, but there are a number of scientists who have looked at gas hydrates as contributing to this recent change.”

 

Higher in the zone

 

Hydrates are a frozen mixture of water and gas, primarily methane.

 

They form under the frigid temperatures and high pressures found in ocean sediments and under the permafrost on land.

 

In the ocean, hydrates exist in a “zone of stability” under the seafloor in locations where water depths exceed 500m.

 

But the results of an expedition carried out by the IODP off Vancouver Island are putting a significant new perspective on this profile.

The international marine research organisation used the drilling facility and laboratories of the US research vessel Joides Resolution to retrieve core samples from a geological area known as the (northern) Cascadia Margin.

 

The pressurised cores pulled back on to the ship had copious hydrate deposits – and at a level in the stability zone that was much higher than expected.

 

“Gas hydrates have been studied at Cascadia for 20 years, and there has been an established model for how hydrates form on such a margin,” said IODP expedition co-chief Dr Michael Riedel of McGill University, Montreal.

 

“But we found from our expedition that this model is way too simple and has to be modified. We found anomalous occurrences of high concentrations of gas hydrate at relatively shallow depths, 60-100m below the seafloor.”

 

Commercial resource

 

As well as suggesting hydrates would be more concentrated at deeper levels below the seafloor, the old model also predicted the ices would be evenly distributed among the various grain sizes that comprise the sediments.

 

This has now been found wanting, too.

 

“After repeatedly recovering high concentrations of gas hydrate in sand-rich layers of sediment, we’re reporting strong support for sediment grain size as a controlling factor in gas hydrate formation,” said Dr Collett, who is affiliated to the US Geological Survey.

 

Vast reserves of the ices are thought to exist. One calculation suggests some 10,000 billion tonnes of carbon is stored in the form of gas hydrate around the world. That is twice the volume stored in all known reserves of fossil fuels – oil, coal and natural gas.

“If you start looking at this as a carbon sink – the amount of carbon that could be available to climate change and to altering the atmosphere and its chemistry – this could be a very significant contribution,” explained Dr Collett.

 

Hydrates have naturally excited the attention of mineral companies, and a number of them are now investing considerable sums of money in trying to exploit the resource.

 

BP will begin an exploratory programme to drill hydrates under the Alaskan permafrost in the New Year.

 

The IODP results were reported here at the American Geophysical Union Fall Meeting.

 

Jonathan.Amos-INTERNET@bbc.co.uk

 

Story from BBC NEWS:

http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/6166011.stm

 

Published: 2006/12/13 20:47:57 GMT

 

© BBC 2013

 

 

22 February 2013 Last updated at 14:41

 

Siberian permafrost thaw warning sparked by cave data [2013]

 

Evidence from Siberian caves suggests that a global temperature rise of 1.5C could see permafrost thaw over a large area of Siberia.

 

A study shows that more than a trillion tonnes of the greenhouse gases CO2 and methane could be released into the atmosphere as a result.

 

An international team has published details in the journal Science.

 

The evidence comes from analysis of stalactites and stalagmites in caves along the “permafrost frontier”.

 

This is where ground begins to be permanently frozen in layers that can be tens to hundreds of metres thick.

 

Stalactites and stalagmites only grow when liquid rainwater and snowmelt drip into the caves.

 

So these formations record 500,000 years of changing permafrost conditions – including warmer periods similar to the climate of today.

 

 

Thawing of permafrost would have huge implications for ecosystems, says the team

The records from a particularly warm period called Marine Isotopic Stage 11, which occurred around 400,000 years ago, suggest that warming of 1.5C compared to the present is enough to cause substantial thawing of permafrost – even in areas far north from its present-day southern limit.

 

“The stalactites and stalagmites from these caves are a way of looking back in time to see how warm periods similar to our modern climate affect how far permafrost extends across Siberia,” said Dr Anton Vaks from the University of Oxford.

 

“As permafrost covers 24% of the land surface of the Northern Hemisphere, significant thawing could affect vast areas and release (billions of tonnes) of carbon.”

 

He added: “‘This has huge implications for ecosystems in the region, and for aspects of the human environment.

 

“For instance, natural gas facilities in the region, as well as power lines, roads, railways and buildings are all built on permafrost and are vulnerable to thawing. Such a thaw could damage this infrastructure with obvious economic implications.”

 

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