Methane (CH4) is by far the most important non-CO2 greenhouse gas – a relatively potent greenhouse gas responsible for nearly as much global warming as all other non-CO2 greenhouse gases put together. Methane is created naturally near the Earth’s surface by microorganisms by the process of methanogenesis and carried into the stratosphere by rising air in the tropics. It is important because of the potential harm it has for global warming, but it also has value as an energy source. There is much less methane in the atmosphere than CO2: about 1800 parts per billion (ppb), compared with an estimated 410 parts per million of CO2. However its potential for global warming has been estimated at 25 times greater than CO2 . While CO2 emissions are estimated to contribute 75% to global warming effects, methane is a distant second at 15%. And as with other greenhouse gases, methane levels have been rising; they are now more than twice what they were in the early 1800s when methane levels were closer to 715ppb. Half of current emissions is human-related which includes landfills, agriculture and coal mining.
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Below:
- Science of methane
- Methane – North America
- Dangers of methane
- Permafrost methane
- Trapped methane danger
- Benefits of methane
See also Natural Gas / Fracking / Agriculture
Science of methane
Methane is roughly 86 times as potent as CO2 as a driver of climate change over a period of 20 years, or 35 times as potent over the span of a century – link
April 2018: Scientists struggle to explain a worrying rise in atmospheric methane. Of the 50bn-tonne total CO2 equivalent emissions caused by humans every year, 70% is carbon dioxide itself, and half the remaining 15bn tonnes is methane. In the past decade methane levels have shot up to the extent that the atmosphere contains two-and-a-half times as much of the gas as it did before the Industrial Revolution. Molecule for molecule methane’s warming effect (calculated over 100 years) is 25 times higher than CO2. A second worrying concern is that methane’s latest rise is poorly understood. link
August 2017: Tapping methane from ice. In May of this year, China claimed a breakthrough in tapping an obscure fossil fuel resource when it sucked a steady flow of methane gas out of frozen mud on the seafloor. That same month, Japan did the same. And in the United States, researchers pulled a core of muddy, methane-soaked ice from the bottom of the Gulf of Mexico. The idea of exploiting this quirky fuel source would have been considered madness a couple of decades ago. Until recently, methane-soaked ice was considered explosively unstable, and wildly expensive. link
January 2011: Science advancing on methane’s behavior in carbon cycle. Studies shows that freshwater sources, such as lakes and streams, contribute more methane to the atmosphere than previously thought, another clarifies how methane is consistently cleansed from the atmosphere. Together, they provide a clearer window on methane’s behavior in two places in the carbon cycle, improving the tool set scientists can use to track and measure the contribution of the greenhouse gas on warming global temperatures. Atmospheric methane levels were relatively constant from 1999 to 2006, but in 2007 to 2009, globally averaged methane levels began to increase. 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. link
April 2014: Methane hydrates – dirty fuel or energy savior? Methane hydrate, otherwise known as fire ice, presents as ice crystals with natural methane gas locked inside, and is a hydrocarbon unlike any other we know. They are formed through a combination of low temperatures and high pressure, and are found primarily on the edge of continental shelves where the seabed drops sharply away into the deep ocean floor. The deposits of these compounds are enormous. “Estimates suggest that there is about the same amount of carbon in methane hydrates as there is in every other organic carbon store on the planet,” says Chris Rochelle of the British Geological Survey. In other words, there is more energy in methane hydrates than in all the world’s oil, coal and gas put together. But as with any fossil fuel source, there are risks and technical problems. link
March 2017: Methane emissions from trees. A new study from the University of Delaware is one of the first in the world to show that tree trunks in upland forests actually emit methane rather than store it, representing a new, previously unaccounted source of this powerful greenhouse gas. link
Methane – North America
June 2018: Thaw of Antarctic ice lifts up land, might slow sea level rise. Antarctica’s bedrock is rising surprisingly fast as a vast mass of ice melts into the oceans, a trend that might slow an ascent in sea levels caused by global warming, scientists said on Thursday. However, the process could to be too slow to save the ice sheet from a possible collapse triggered by global warming. link
November 2017: EPA revises social cost of methane. The Trump administration is tweaking how it measures the costs of emitting methane, a move that will have major impacts for climate rules. Known as the social cost of methane, this obscure metric is a younger counterpart to the better-known social cost of carbon. Economists and scientists developed the calculation to give policymakers a better idea of the economic benefits of cutting methane emissions. Its revision by the Trump administration is part of a broader shift within the federal government to downplay the impacts of climate change and will have important implications for how the EPA regulates greenhouse gases. link
October 2017: Federal court rules against Trump administration on methane. The ruling says the Trump administration broke the law when it tried to delay an Obama administration rule related to greenhouse gas released through oil and natural gas drilling, saying the Interior Department cannot use a provision in the Administrative Procedure Act to delay the rule on methane emissions on federal land, as it tried to do in June. link
March 2016: Canada and USA agree reductions on methane. The EPA will limit methane emissions from existing oil and gas facilities, a huge move by the federal agency, announced in conjunction as President Obama’s met with Canadian Prime Minister Justin Trudeau. The new rule will help the two countries achieve their goal of cutting methane emissions from oil and gas by 40 to 45% below 2012 levels by 2025. link
| Government EPA rulings
May 2017: EPA halts the Obama administration rule to cut down on pollution of methane – link Update – July 3 2017: Court rejects EPA’s attempt to halt Obama-era methane rule. link May 2016: EPA cracks down on methane emissions. The Environmental Protection Agency announced new rules to significantly reduce methane emissions from new oil and gas facilities as well as those undergoing modifications. New regulations cover new oil and gas facilities, but methane from existing sites remains unregulated, a crucial step to reaching greenhouse gas reduction goals. link December 2012: In 2009, EPA determined that methane and other greenhouse gases endanger the public’s health and welfare. Pound for pound, methane warms the climate 22 times more than CO2 over a 100-year period. The EPA’s decision not to directly address the emissions of methane from oil and natural gas operations, including hydrofracking, leaves nearly 95% of these emissions uncontrolled. link |
Dangers of methane
September 2017: Methane’s rapid increase in last decade. After rising slowly from 2000 to 2006, the concentration of methane in the air has climbed 10 times more quickly in the last decade, according to earlier research. Methane emissions from cattle are 11% higher than previously estimated. Bigger livestock in larger numbers in more regions has led to methane in the air climbing faster than predicted due to ‘out-of-date data’. link
March 2017: Gas power plants emit up to 120 times more methane than previously thought. Research from scientists at Purdue University and the Environmental Defence Fund study found: “Average methane emission rates were larger than facility-reported estimates by factors of 21 to 120 (at natural gas power plants) and 11 to 90 (at refineries).”link
January 2017: Methane drives sea level rise for centuries. Even if humans stopped emitting greenhouse gases into the atmosphere tomorrow, the thermal expansion effect would continue in the oceans for centuries more, making it effectively irreversible in our lifetimes. Methane can have centuries-long impacts on the expanding oceans. The science behind thermal expansion is relatively simple: When greenhouse gases go into the atmosphere, they cause air temperatures to rise. Some of the heat ends up being absorbed into the oceans, causing the water to expand in volume. Climate scientists generally take thermal expansion into account when making modeled projections about future sea level rise. link
December 2016: Atmospheric levels of methane spiking. Scientists report concentrations of methane in the atmosphere that were rising only at about 0.5 parts per billion per year in the early 2000s have now spiked by 12.5 parts per billion in 2014 and 9.9 parts per billion in 2015. With carbon dioxide rising more slowly, that means that a higher fraction of the global warming that we see will be the result of methane, at least in the next decade or so. link
October 2016: Methane emissions far higher than thought. Researchers who pulled together the biggest database yet of worldwide methane emissions found that, after natural sources were discounted, emissions from gas, oil and coal production were 20-60% greater than existing estimates. (Methane makes up 16% of global greenhouse gases.) link
| USA news
January 2015: Obama action on methane emissions misses 90% of pollution. In a further use of the president’s executive authority, the White House unveiled a strategy aimed at cutting methane, one of the most powerful heat-trapping gases, by 40% to 45% over the next decade. However, the plan applied only to future oil and gas wells and infrastructure, and not the thousands of existing sites which are leaking methane, campaigners noted. link February 2015: U.S. tied to global spike in methane emissions. The U.S. is responsible for as much as 60% of global methane emissions growth over the last decade according to the latest study. Robert Howarth, a Cornell University ecologist and methane researcher, said “the increase almost certainly must be coming from the fracking and from the increase in use of natural gas.” link October 2016: Super emitters to blame for majority of methane emissions in U.S. Over the last two decades, the rise in natural gas extraction has resulted in a dramatic increase in methane emissions in the United States, Canada and elsewhere. Researchers call these leaking gas wells “super emitters,” as the largest 5% of leaks are typically responsible for more than 50% of the total volume of leakage. Climate scientists estimate as much as 25% of man-made global warming is caused by methane emissions. link |
September 2016: Reservoirs a source of methane. Reservoirs emit global warming gases, and a team of researchers has now tallied just how much those gases impact the climate. Globally, reservoirs are responsible for about 1.3% of the world’s man-made greenhouse gas emissions each year. link
January 2013: Methane leaks erode green credentials of natural gas. Scientists are once again reporting alarmingly high methane emissions from an oil and gas field, underscoring questions about the environmental benefits of the boom in natural-gas production. If methane is leaking from fields across the country at similar rates, it could be offsetting much of the climate benefit of the ongoing shift from coal-to gas-fired plants for electricity generation. link
February 2013: Major methane release is almost inevitable. We are on the cusp of a tipping point in the climate. If the global climate warms another few tenths of a degree, a large expanse of the Siberian permafrost will start to melt uncontrollably. link
Permafrost methane
July 2017: Methane seeps out from Arctic permafrost. Global warming may be unleashing new sources of heat-trapping methane from layers of oil and gas that have been buried deep beneath Arctic permafrost for millennia. There is more evidence that the loss of permafrost and glaciers opens conduits for the release of geologic methane to the atmosphere, constituting a newly identified, powerful feedback to climate warming. These studies suggest that the geologic methane sources will likely increase in the future as permafrost warms and becomes more permeable. link
April 2017: Massive methane gas bubbles under the Russian permafrost could explode anytime. Russian scientists have recently discovered some 7,000 underground methane bubbles in Siberia most likely linked to thawing permafrost. In March 2017 Siberia saw stunning temperatures, according to NASA’s latest monthly report. Globally, it was the second hottest March on record, losing out only to March 2016. Parts of Siberia and the Arctic were as much as 12.1°C above the 1951–1980 average. link
July 2011: Russia may lose 30% of permafrost by 2050. 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
Permafrost methane time bomb.
August 2013: Arctic methane time-bomb. Debate over the plausibility of a catastrophic release of methane in coming decades due to thawing Arctic permafrost has escalated following a New Nature paper warned that exactly this scenario could trigger costs equivalent to the annual GDP of the global economy. Scientists of different persuasions remain fundamentally divided over whether such a scenario is even plausible. There is an emerging consensus among East Siberia Arctic Shelf specialists based on continuing fieldwork, highlighting a real danger of unprecedented quantities of methane venting due to thawing permafrost. A 2010 scientific study led by the UK’s Met Office recognised the plausibility of catastrophic carbon releases from Arctic permafrost thawing of between 50-100 Gt this century, with a 40 Gt carbon release from the Siberian Yedoma region possible over four decades. link
Trapped methane dangers
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 (Photo – methane bubbling up – source ) [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.
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
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
| A frozen peat bog in Siberia, the size of France and Germany combined, contains billions of tonnes of greenhouse gases and has started to melt for the first time since it formed 11,000 years ago at the end of the last ice age. Carbon that accumulated over this time is stored in permafrost soils which occupy more than 60% of Russia’s 17 million square-kilometre land area. Researchers who have recently returned from the region found an area of permafrost spanning a million square kilometers. According to Larry Smith, a hydrologist at the University of California, Los Angeles, the west Siberian peat bog could hold some 70 bn tonnes of methane, a quarter of all of the methane stored in the ground around the world. Stephen Sitch, a climate scientist at England’s Met Office in Exeter, calculates that even if methane seeped from the permafrost over the next 100 years, it would add around 700m tonnes of carbon into the atmosphere each year, roughly the same amount that is released annually from the world’s wetlands and agriculture. 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. link
Benefits of methane
November 2017: Breakthrough process for directly converting methane to methanol. The direct oxidation of methane, found in natural gas, into methanol at low temperatures has long been a holy grail. Now, researchers have found a breakthrough way to accomplish the feat using a heterogeneous catalyst and cheap molecular oxygen, according to a paper published in the journal Nature by a team led by Tufts University chemical engineers. Methanol is a key feedstock for the production of chemicals, some of which are used to make products such as plastics, plywood and paints. Methanol also can fuel vehicles or be reformed to produce high-grade hydrogen for fuel cells. 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. Methane to Markets Partnership countries account for approximately 60% of global methane emissions.
March 2013: Japan successful at extracting natural gas from frozen methane. Japan says it has successfully extracted natural gas from frozen methane hydrate off its central coast, in a world first. Methane hydrates, or clathrates, are a type of frozen “cage” of molecules of methane and water. The gas field is about 50km away from Japan’s main island, in the Nankai Trough, and could provide more than a decade of Japan’s gas consumption. Other countries including Canada, the US and China have been looking into ways of exploiting methane hydrate deposits as well. 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