METHANE

Recent news:

Jan. 9 2012: Amount of methane frozen unknown. We don't know the total amount of methane frozen deep beneath the ocean, but we suspect it could rival the rest of fossil fuels combined. And we don't know how much is frozen in the Arctic's thawing permafrost and lake sediments. We do know those methane deposits are seeping into the atmosphere, however. And the possibility of a catastrophic release is of, course, what gives methane its power over the imagination. We have seen methane bubbling from the sea floor in the Arctic. Lakes provide an escape path for the methane by creating “thaw bulbs” in the underlying soil, and lakes are everywhere appearing and disappearing in the Arctic as the permafrost melts. Yet so far we haven't seen iron-clad evidence of greater methane releases due to anthropogenic warming, though such an event is certainly believable for the coming century. This brings us to the key question: What effect would a methane release have on climate? The impact depends on whether methane is released all at once or in an ongoing, sustained manner. link

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Below

• Science of methane
• Benefits of methane
• Trapped methane danger
• Methane from animals/agriculture             

Methane is produced in environments with little or no oxygen by bacteria that feast on decomposing organic matter, such as grasses and wood. Almost half of the world’s methane comes from natural sources such as wetlands, rivers and streams, gas hydrates on the ocean floor, and permafrost. Termites, surprisingly, are the second largest source of global natural methane emissions; they produce the gas as part of their normal digestive process.

According to the EPA, methane remains in the atmosphere approximately 10-12 years and is over 20 times more effective in trapping heat than carbon dioxide (CO2) It has a half-life of seven years (if no methane was added, then every seven years, the amount of methane would halve). The Intergovernmental Panel on Climate Change (IPCC) estimates that atmospheric concentrations are about two and a half times those seen in pre-industrial times. "A fifth of all greenhouse gas-induced global warming has been due to methane since pre-industrial times," said Australian climate scientist Paul Fraser, where ruminant farm animals belch out vast amounts of the gas.

Methane could power the world. Two methane hydrate deposits off the coast of South Carolina reportedly hold enough natural gas to power the United States for a hundred years. Other estimates say that worldwide methane deposits contain more energy than coal, oil and all other fossil fuels combined. On the plus side, the relative abundance of methane and its clean burning process makes it a very attractive fuel. It is the most plentiful hydrocarbon in Earth's crust and is a main component of natural gas. Chemists in the U.K. have developed a way to create a solid form of the gas that looks like granulated sugar and can be stored and poured. There is a huge amount of energy in these resources: the question is how much of that material can we recover.  Most of that methane is locked inside ice crystals in the Arctic or at the bottom of the ocean. Extracting those deposits is difficult because high pressures are needed and the temperatures are low.  link  

September 2010: Japan looks to drill for frozen methane. In a bid to shore up its precarious energy security, Japan is looking at deep drilling for controversial frozen methane. The methane lies hundreds of meters below the sea, and deeper still below sediments. Concern have been raised that digging for frozen methane would destabilise the methane beds which contain enough gas worldwide to snuff out most complex life on earth. link

October 2010:  Methane to Markets Partnership  was launched in 2004 with 14 partner countries and has since expanded to include 38 governments, which together represent approximately 70% of the world’s estimated anthropogenic methane emissions and include the top 10 methane emitting countries. link   (Partner countries)

Many climate scientists think that the frozen Arctic tundra is a ticking time bomb in terms of global warming, because it holds vast amounts of methane. Over thousands of years the methane has accumulated under the ground at northern latitudes all around the world, and has effectively been taken out of circulation by the permafrost acting as an impermeable lid. But as the permafrost begins to melt in rising temperatures, the lid may open with potentially catastrophic results.

March 2010: Vast East Siberian Arctic Shelf methane stores destabilizing. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming according to the National Science Foundation. Methane release from the not-so-perma-frost is the most dangerous amplifying feedback in the entire carbon cycle. Research published in the journal Science      (Photo - methane bubbling up - source )        finds a key “lid” on “the large sub-sea permafrost carbon reservoir” near Eastern Siberia “is clearly perforated, and sedimentary CH₄ [methane] is escaping to the atmosphere.” Scientists learned last year that the permamelt contains a staggering 1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere, much of which would be released as methane. Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years. The carbon is locked in a freezer in the part of the planet warming up the fastest. Half the land-based permafrost would vanish by mid-century on our current emissions path. link.  [No climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.]  More than 50 billion tons of methane could be unleashed from Siberian lakes alone, more than 10 times the amount now in the atmosphere.  

Permafrost, or soil that is permanently frozen, covers about 63% of Russia, but has been greatly affected by climate change in recent decades.  In the next 25 to 30 years, the area of permafrost in Russia may shrink by 10-18%, By the middle of the century, it can shrink by 15-30% and the boundary of the permafrost may shift to the north-east by 150-200 kilometres. Predictions suggest that temperature of the zones of frozen soil in oil and gas-rich western Siberia territories will rise by up to two degrees Celsius to just three or four degrees below zero.  link

August 2011: Temporary drop of methane in atmosphere. Scientists say that there has been a mysterious decline in the growth of methane in the atmosphere in the last decades of the 20th Century. Researchers writing in the journal Nature have come up with two widely differing theories as to the cause. One suggests the decline was caused by greater commercial use of natural gas, the other that increased use in Asia of artificial fertiliser was responsible. Both studies agree that human activities are the key element. And there are suggestions that methane levels are now on the rise again. link

March 2010: Vast East Siberian Arctic Shelf methane stores destabilizing. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming according to the National Science Foundation. Methane release from the not-so-perma-frost is the most dangerous amplifying feedback in the entire carbon cycle. Research published in the journal Science finds a key “lid” on “the large sub-sea permafrost carbon reservoir” near Eastern Siberia “is clearly perforated, and sedimentary CH₄ [methane] is escaping to the atmosphere.” Scientists learned last year that the permamelt contains a staggering 1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere, much of which would be released as methane.  Methane is 25 times as potent a heat-trapping gas as CO2 over a 100 year time horizon, but 72 times as potent over 20 years. The carbon is locked in a freezer in the part of the planet warming up the fastest. Half the land-based permafrost would vanish by mid-century on our current emissions path. link.  [No climate model currently incorporates the amplifying feedback from methane released by a defrosting tundra.]

January 2009: Siberian methane release begins. 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. Until recently the undersea permafrost was considered to be stable but now scientists think the release of such a powerful greenhouse gas may accelerate global warming. 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. link 

August 2009: Scientists say they have evidence that 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 gas is normally trapped as "methane hydrate" in sediment under the ocean floor. The most significant finding is that climate change means the gas is being released from more and deeper areas of the Arctic ocean. 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, England, 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."  link

October 2010: Reservoirs a neglected source of methane emissions. As an example, a reservoir on the Aare in Switzerland produces 150 tonnes of methane a year. This is about the same amount as is emitted annually by around 2,000 cows. "So hydropower isn't quite as climate-neutral as people have assumed in the past," says environmental chemist Tonya Del Sontro. link

The number one source of methane worldwide is animal agriculture. On a global basis, according to the FAO livestock is responsible for some 18% of all greenhouse gases emitted. Methane is the most important greenhouse gas on a dairy farm. The FAO estimates that about 52% of all greenhouse gases from the dairy sector is in the form of methane. link   

March 2011: A U.K. Department for Environment, Food and Rural Affairs (Defra) study says changing what cows and sheep eat could help to trim the 41% of methane emissions that result from farming. Flatulent cows, goats and sheep account for 4.5% of the UK's overall greenhouse gas emissions. link

More than half of methane released each year comes from human activities, notably farming. The Journal of Animal Science says that ruminant animals produce between 250 and 500 liters of methane gas every day. The combined environmental effect of the world’s livestock is enormous. There are around 1.5 billion cattle on our planet - more than double the number 30 years ago. Normally a cow's stomach is pretty inefficient - 80% of food ingested comes out as waste or methane. There are also over a billion sheep and some 800 million goats. Animal agriculture produces more than 100 million tons of methane a year and many organizations urge a vegetarian diet to help avert climate catastrophe. Changing the ruminants' diets is another approach. A trial in Scotland on lamb recently obtained a 70% decrease in methane formation, while in New Zealand, where agriculture accounts for almost 50% of the country's greenhouse gas emissions, scientists are working on reducing methane by getting rid of the microbes in animals' stomachs that produce methane. link

           The world’s total meat supply was 71 million tons in 1961. 
           By 2007 it was estimated to be 284 million tons. 
           It is expected to double again by 2050.    
           Producing meat takes up 70% of the world's farming land
            . . .  and generates a fifth of greenhouse gas emissions.

There is a counter argument. 
Don't blame dairy cows for greenhouse gas emissions - new study
Eating less meat and dairy products won't have major impact on global warming, expert argues. Read here
  
Across the globe, chickens and pigs are doing their bit to curb global warming. But cows and sheep still have some catching up to do. "It's been argued that the reductions from methane are potentially cheaper than from carbon dioxide," said Bill Hare, climate policy director for Greenpeace. link  However, manure from pigs (as well as chickens) emit methane which we should be harnessing for fuel. link  According to a recent report from the UN Food and Agriculture Organization, livestock production, dominated in the West by large-scale factory farming, is responsible for 18% of the world's greenhouse gas emissions; a bigger share than all of the world's transport. link

Interesting fact:
Cows emit a massive amount of methane through belching, with a lesser amount through flatulence. Statistics vary regarding how much methane the average dairy cow expels. Some experts say 100 liters to 200 liters a day while others say it's up to 500 liters a day. more
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Australian scientists are hoping to breed sheep that burp less as part of efforts to tackle climate change - about 16% of Australia's greenhouse emissions come from agriculture and 90% of the methane that sheep and cattle and goats produce comes from the rumen, and that's burped out. link

Researchers in Argentina, which has more than 55 million cows, discovered methane from cows accounts for more than 30% of the country's total greenhouse emissions. Guillermo Berra, a researcher at the National Institute of Agricultural Technology, said every cow produces between 800 to 1,000 litres of emissions every day. Scientists are now carrying out trials of new diets designed to improve cows' digestion and hopefully reduce global warming. Silvia Valtorta, of the National Council of Scientific and Technical Investigations, said that by feeding cows clover and alfalfa instead of grain "you can reduce methane emissions by 25%".  link