Tag Archives: Methane

Low-flatulence livestock can cool planet

FOR IMMEDIATE RELEASE Farmers may be able to rear livestock which produce fewer emissions from their stomachs of methane, one of the most important greenhouse gases. LONDON, 18 January – Stand by for a new breed of farm animal – the low-methane cow. European scientists are collaborating in a bid to find a cow that makes the same milk, but manages to do so while emitting lower levels of natural gas from the ruminant stomach. Methane is a fact of farm life: cows eat grass, hay and silage, and then proceed to digest it with help from an arsenal of stomach and gut microbes. But methane is also a potent greenhouse gas (GHG): weight for weight it is more than 20 times more potent than carbon dioxide over a century. About a fifth of all GHG emissions from agriculture are directly released from the stomachs of the world’s cattle herds. And a consortium called RuminOmics has launched research into every aspect of animal husbandry in an attempt to lower the methane productivity while keeping up the dairy output. Phil Garnsworthy is a dairy scientist at the University of Nottingham, UK, and one of the project partners. He reasons that cattle vary quite dramatically in the levels of methane from their stomachs, so it would be possible to imagine a dairy herd that produced the same volume of milk while reducing their gaseous discharges. There are other factors: as every human knows too well, gas output is linked to diet. “It is possible to imagine cutting emissions from cattle by a fifth, using a combination approach in which you would breed from lower-emitting cattle as well as changing their diets”, said Professor Garnsworthy.

More profitable

Inheritance, too, may play a role. “There are three issues: diet, genetics and the microbiology of the cow’s rumen”, says Lorenzo Morelli of the Catholic University of the Sacred Heart in Piacenza, Italy. “We think that animal genetics may well influence their gut microbiology. However, this link has not been proved and we are still in the data collection phase.” Most animal husbandry research has concentrated on raising animal productivity and fertility. But lower methane output could join the list of desired characteristics. There could even be a direct pay-off for the herdsmen. “The methane is lost energy that could go into producing milk”, says Morelli. “So if we can find the right genetic mix, we can find cattle that are less polluting, more productive, and more profitable for the farmer.” Methane is a short-lived gas: it stays in the atmosphere for about 10 years. Carbon dioxide – always the dominant greenhouse gas – is released in far greater quantities, and a molecule of carbon dioxide stays in the atmosphere for about 100 years.

Multiple gains

But the same volume of methane over a 20-year period will trap 70 times the heat that carbon dioxide retains, so any serious reduction in methane output could make a significant difference to the pace of climate change. Some scientists have argued that it would be better simply to reduce the herds, rather than their digestive output. In December an international team argued in the journal Nature Climate Change that since methane was the second most abundant GHG, one of the most effective ways to cut output would be to reduce global populations of ruminant livestock – sheep, goats, camels and buffalo as well as cattle are all ruminants. Globally, they argued, the numbers of ruminant livestock had risen by 50% in the last 50 years, and now about 3.6 billion animals were grazing on about one quarter of the Earth’s land area. Furthermore, a third of all arable land was used to grow feed for these animals. “Cutting the number of ruminant livestock could have additional benefits for food security, human health and environmental conservation involving water quality, wildlife habitat and biodiversity”, said Peter Smith of the University of Aberdeen in Scotland, one of the authors. – Climate News Network

FOR IMMEDIATE RELEASE Farmers may be able to rear livestock which produce fewer emissions from their stomachs of methane, one of the most important greenhouse gases. LONDON, 18 January – Stand by for a new breed of farm animal – the low-methane cow. European scientists are collaborating in a bid to find a cow that makes the same milk, but manages to do so while emitting lower levels of natural gas from the ruminant stomach. Methane is a fact of farm life: cows eat grass, hay and silage, and then proceed to digest it with help from an arsenal of stomach and gut microbes. But methane is also a potent greenhouse gas (GHG): weight for weight it is more than 20 times more potent than carbon dioxide over a century. About a fifth of all GHG emissions from agriculture are directly released from the stomachs of the world’s cattle herds. And a consortium called RuminOmics has launched research into every aspect of animal husbandry in an attempt to lower the methane productivity while keeping up the dairy output. Phil Garnsworthy is a dairy scientist at the University of Nottingham, UK, and one of the project partners. He reasons that cattle vary quite dramatically in the levels of methane from their stomachs, so it would be possible to imagine a dairy herd that produced the same volume of milk while reducing their gaseous discharges. There are other factors: as every human knows too well, gas output is linked to diet. “It is possible to imagine cutting emissions from cattle by a fifth, using a combination approach in which you would breed from lower-emitting cattle as well as changing their diets”, said Professor Garnsworthy.

More profitable

Inheritance, too, may play a role. “There are three issues: diet, genetics and the microbiology of the cow’s rumen”, says Lorenzo Morelli of the Catholic University of the Sacred Heart in Piacenza, Italy. “We think that animal genetics may well influence their gut microbiology. However, this link has not been proved and we are still in the data collection phase.” Most animal husbandry research has concentrated on raising animal productivity and fertility. But lower methane output could join the list of desired characteristics. There could even be a direct pay-off for the herdsmen. “The methane is lost energy that could go into producing milk”, says Morelli. “So if we can find the right genetic mix, we can find cattle that are less polluting, more productive, and more profitable for the farmer.” Methane is a short-lived gas: it stays in the atmosphere for about 10 years. Carbon dioxide – always the dominant greenhouse gas – is released in far greater quantities, and a molecule of carbon dioxide stays in the atmosphere for about 100 years.

Multiple gains

But the same volume of methane over a 20-year period will trap 70 times the heat that carbon dioxide retains, so any serious reduction in methane output could make a significant difference to the pace of climate change. Some scientists have argued that it would be better simply to reduce the herds, rather than their digestive output. In December an international team argued in the journal Nature Climate Change that since methane was the second most abundant GHG, one of the most effective ways to cut output would be to reduce global populations of ruminant livestock – sheep, goats, camels and buffalo as well as cattle are all ruminants. Globally, they argued, the numbers of ruminant livestock had risen by 50% in the last 50 years, and now about 3.6 billion animals were grazing on about one quarter of the Earth’s land area. Furthermore, a third of all arable land was used to grow feed for these animals. “Cutting the number of ruminant livestock could have additional benefits for food security, human health and environmental conservation involving water quality, wildlife habitat and biodiversity”, said Peter Smith of the University of Aberdeen in Scotland, one of the authors. – Climate News Network

Frack first, repent at leisure

FOR IMMEDIATE RELEASE The arguments for and against fracking seem clear-cut. But it’s not that simple, and there is mounting evidence that exploiting shale gas may be neither necessary nor sensible. LONDON, 17 August – As the international debate intensifies over the arguments for and against exploiting shale gas, the largest British nature conservation charity has objected to proposals to drill at two sites in Britain. The Royal Society for the Protection of Birds is concerned that fracking – hydraulic fracturing of underground rock – at a site in northern England close to an internationally important protected area for pink-footed geese and whooper swans could disturb the birds. With the second site, in the south of England, the RSPB is objecting because it says the developers have not carried out an assessment of the environmental impact of the exploitation. But significantly, the conservationists are raising a second objection as well: that “increasing oil and gas use will scupper our chances of meeting climate targets.” Some supporters of shale exploitation say the cheaper and (relatively) cleaner energy it would produce could serve as a bridge to usher the UK into an era of secure supplies and low-carbon emissions. Others see shale not as a bridge but as a dead end. The RSPB concludes: “…concentrating our resources on extracting fossil fuel from the ground instead of investing in renewable energy threatens to undermine our commitment to avoiding dangerous levels of climate change.”

Coal’s silver lining

But one climate scientist uses a different argument against shale gas: he says exploiting it could in fact worsen climate change, the very problem it is meant to solve. Tom Wigley, of the National Center for Atmospheric Research in Boulder, Colorado, reported as long ago as 2011 in the journal Climatic Change that replacing coal with gas could increase the rate of global warming for decades to come. Dr Wigley concluded that carbon dioxide emissions from fossil fuel combustion could certainly be cut by burning natural gas rather than coal, as gas produces about half as much CO2 for each unit of primary energy as coal does. But coal does something else as well. It releases a lot of sulphur dioxide and black carbon, which help to cool the climate. The British journalist Fred Pearce, writing in the journal New Scientist, says Wigley told a recent conference that these releases counteract up to 40% of the warming effect of burning coal. Additionally, the technology used in fracking also causes methane to leak into the atmosphere. Methane is at least 23% more potent as a greenhouse gas than CO2, and Dr Wigley says a change from coal to gas will bring benefits this century only if leakage rates are below 2%.

Easier low-tech solution

If they reached 10%, the highest current US estimate, the gas would increase rather than decrease global warming until the middle of the next century, though the overall effects on global average temperature over that century would be small. And even if resorting to shale gas does not worsen climate change, it can still be an unnecessarily hi-tech solution which blinds its supporters to a far simpler answer, some critics argue. The London Guardian quotes the UK’s Anaerobic Digestion and Biogas Association as saying a tenth of the country’s domestic gas needs could be supplied by biogas, given the UK’s wealth of waste and agricultural products. This, the Association says, could save the UK at least 7.5m tonnes of CO2 a year, because the waste would otherwise be sent to landfill or left to rot and release methane. The country is estimated to produce 15 million tonnes of food waste a year, and about 90 m tonnes of another potent source of energy, animal waste. But only a small part of both is used for producing energy. One British company which is successfully exploiting the bio-waste market is producing electricity and fertiliser, and also preventing the release of thousands of tonnes of CO2 annually. – Climate News Network

FOR IMMEDIATE RELEASE The arguments for and against fracking seem clear-cut. But it’s not that simple, and there is mounting evidence that exploiting shale gas may be neither necessary nor sensible. LONDON, 17 August – As the international debate intensifies over the arguments for and against exploiting shale gas, the largest British nature conservation charity has objected to proposals to drill at two sites in Britain. The Royal Society for the Protection of Birds is concerned that fracking – hydraulic fracturing of underground rock – at a site in northern England close to an internationally important protected area for pink-footed geese and whooper swans could disturb the birds. With the second site, in the south of England, the RSPB is objecting because it says the developers have not carried out an assessment of the environmental impact of the exploitation. But significantly, the conservationists are raising a second objection as well: that “increasing oil and gas use will scupper our chances of meeting climate targets.” Some supporters of shale exploitation say the cheaper and (relatively) cleaner energy it would produce could serve as a bridge to usher the UK into an era of secure supplies and low-carbon emissions. Others see shale not as a bridge but as a dead end. The RSPB concludes: “…concentrating our resources on extracting fossil fuel from the ground instead of investing in renewable energy threatens to undermine our commitment to avoiding dangerous levels of climate change.”

Coal’s silver lining

But one climate scientist uses a different argument against shale gas: he says exploiting it could in fact worsen climate change, the very problem it is meant to solve. Tom Wigley, of the National Center for Atmospheric Research in Boulder, Colorado, reported as long ago as 2011 in the journal Climatic Change that replacing coal with gas could increase the rate of global warming for decades to come. Dr Wigley concluded that carbon dioxide emissions from fossil fuel combustion could certainly be cut by burning natural gas rather than coal, as gas produces about half as much CO2 for each unit of primary energy as coal does. But coal does something else as well. It releases a lot of sulphur dioxide and black carbon, which help to cool the climate. The British journalist Fred Pearce, writing in the journal New Scientist, says Wigley told a recent conference that these releases counteract up to 40% of the warming effect of burning coal. Additionally, the technology used in fracking also causes methane to leak into the atmosphere. Methane is at least 23% more potent as a greenhouse gas than CO2, and Dr Wigley says a change from coal to gas will bring benefits this century only if leakage rates are below 2%.

Easier low-tech solution

If they reached 10%, the highest current US estimate, the gas would increase rather than decrease global warming until the middle of the next century, though the overall effects on global average temperature over that century would be small. And even if resorting to shale gas does not worsen climate change, it can still be an unnecessarily hi-tech solution which blinds its supporters to a far simpler answer, some critics argue. The London Guardian quotes the UK’s Anaerobic Digestion and Biogas Association as saying a tenth of the country’s domestic gas needs could be supplied by biogas, given the UK’s wealth of waste and agricultural products. This, the Association says, could save the UK at least 7.5m tonnes of CO2 a year, because the waste would otherwise be sent to landfill or left to rot and release methane. The country is estimated to produce 15 million tonnes of food waste a year, and about 90 m tonnes of another potent source of energy, animal waste. But only a small part of both is used for producing energy. One British company which is successfully exploiting the bio-waste market is producing electricity and fertiliser, and also preventing the release of thousands of tonnes of CO2 annually. – Climate News Network

Earthquakes 'may add to methane leaks'

FOR IMMEDIATE RELEASE
Methane is a potent greenhouse gas which in the short term is a much greater threat to global temperatures than carbon dioxide. Now researchers think it can be released by earthquakes.

LONDON, 31 July – And here’s another shuddering twist to the horror story that is climate change: even earthquakes may play a role. Large quantities of methane may have escaped during a violent earthquake that shook the floor of the Arabian Sea in 1945, according to German and Swiss researchers.

David Fischer of the University of Bremen and colleagues from the Alfred Wegener Institute in Bremerhaven and the ETH in Zurich explored the region in a research ship in 2007, and began to examine cores of sediment from the seabed.

One core, from just 1.6 metres below the seabed, contained methane hydrate – an ice-like mixture of methane and water –  and the other did not. But, the researchers report in Nature Geoscience, both cores carried subtle chemical evidence that at some point in the past dramatic quantities of methane or natural gas had actually flowed through the sediments beneath the Arabian Sea.

Since the methane would move as a gas, there is only one direction it could go: bubbling upwards through the sea into the atmosphere. And since methane is a potent greenhouse gas – at least 23 times more potent than carbon dioxide – such escapes could be significant.

“We started going through the literature and found that a major earthquake had occurred close by in 1945”, said Dr Fischer. “Based on several indicators, we postulated that the earthquake led to the fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean.”

The tremor was recorded at magnitude 8.1 – magnitude 9 is about as bad as an earthquake can be – and seismic waves would have raced through the seabed at colossal speeds, quite enough to shake loose any brittle chemical structures in the seabed.

The researchers estimate that the release of methane from that location since that one event could be conservatively estimated at 7.4 million cubic metres: this is roughly the capacity of 10 large gas tankers.

“…hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins…”

This calculation does not take into account how much escaped during the quake itself, and it holds for only one location. “There are probably even more sites in the area that had been affected by the earthquake”, said Dr Fischer.

Such research is another reminder of the complexity of the planet’s climate system. Methane hydrates can be considered as a form of fossil fuel: decayed plant material from millions of years ago, trapped in the mud under the pressing weight of the sea.

Climate scientists have for decades worried about the fragility of these hydrates – as the world warms, they are likely to be released in huge quantities from the Arctic seabed, for instance – but this is the first evidence that natural rather than human-triggered cataclysms could make a serious difference to the global carbon budget.

The lesson is that scientists now have to take such processes into account as they try to calculate the carbon budget for the planet – the quantities of greenhouse gases released into the atmosphere, the volumes subsequently absorbed by plants and then incorporated into sediments.

“We now provide a new mechanism of carbon export that had not been considered before”, said Dr Fischer, and with his co-authors he pushes the message home in the research paper. “We therefore suggest that hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins.” – Climate News Network

FOR IMMEDIATE RELEASE
Methane is a potent greenhouse gas which in the short term is a much greater threat to global temperatures than carbon dioxide. Now researchers think it can be released by earthquakes.

LONDON, 31 July – And here’s another shuddering twist to the horror story that is climate change: even earthquakes may play a role. Large quantities of methane may have escaped during a violent earthquake that shook the floor of the Arabian Sea in 1945, according to German and Swiss researchers.

David Fischer of the University of Bremen and colleagues from the Alfred Wegener Institute in Bremerhaven and the ETH in Zurich explored the region in a research ship in 2007, and began to examine cores of sediment from the seabed.

One core, from just 1.6 metres below the seabed, contained methane hydrate – an ice-like mixture of methane and water –  and the other did not. But, the researchers report in Nature Geoscience, both cores carried subtle chemical evidence that at some point in the past dramatic quantities of methane or natural gas had actually flowed through the sediments beneath the Arabian Sea.

Since the methane would move as a gas, there is only one direction it could go: bubbling upwards through the sea into the atmosphere. And since methane is a potent greenhouse gas – at least 23 times more potent than carbon dioxide – such escapes could be significant.

“We started going through the literature and found that a major earthquake had occurred close by in 1945”, said Dr Fischer. “Based on several indicators, we postulated that the earthquake led to the fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean.”

The tremor was recorded at magnitude 8.1 – magnitude 9 is about as bad as an earthquake can be – and seismic waves would have raced through the seabed at colossal speeds, quite enough to shake loose any brittle chemical structures in the seabed.

The researchers estimate that the release of methane from that location since that one event could be conservatively estimated at 7.4 million cubic metres: this is roughly the capacity of 10 large gas tankers.

“…hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins…”

This calculation does not take into account how much escaped during the quake itself, and it holds for only one location. “There are probably even more sites in the area that had been affected by the earthquake”, said Dr Fischer.

Such research is another reminder of the complexity of the planet’s climate system. Methane hydrates can be considered as a form of fossil fuel: decayed plant material from millions of years ago, trapped in the mud under the pressing weight of the sea.

Climate scientists have for decades worried about the fragility of these hydrates – as the world warms, they are likely to be released in huge quantities from the Arctic seabed, for instance – but this is the first evidence that natural rather than human-triggered cataclysms could make a serious difference to the global carbon budget.

The lesson is that scientists now have to take such processes into account as they try to calculate the carbon budget for the planet – the quantities of greenhouse gases released into the atmosphere, the volumes subsequently absorbed by plants and then incorporated into sediments.

“We now provide a new mechanism of carbon export that had not been considered before”, said Dr Fischer, and with his co-authors he pushes the message home in the research paper. “We therefore suggest that hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins.” – Climate News Network

Earthquakes ‘may add to methane leaks’

FOR IMMEDIATE RELEASE Methane is a potent greenhouse gas which in the short term is a much greater threat to global temperatures than carbon dioxide. Now researchers think it can be released by earthquakes. LONDON, 31 July – And here’s another shuddering twist to the horror story that is climate change: even earthquakes may play a role. Large quantities of methane may have escaped during a violent earthquake that shook the floor of the Arabian Sea in 1945, according to German and Swiss researchers. David Fischer of the University of Bremen and colleagues from the Alfred Wegener Institute in Bremerhaven and the ETH in Zurich explored the region in a research ship in 2007, and began to examine cores of sediment from the seabed. One core, from just 1.6 metres below the seabed, contained methane hydrate – an ice-like mixture of methane and water –  and the other did not. But, the researchers report in Nature Geoscience, both cores carried subtle chemical evidence that at some point in the past dramatic quantities of methane or natural gas had actually flowed through the sediments beneath the Arabian Sea. Since the methane would move as a gas, there is only one direction it could go: bubbling upwards through the sea into the atmosphere. And since methane is a potent greenhouse gas – at least 23 times more potent than carbon dioxide – such escapes could be significant. “We started going through the literature and found that a major earthquake had occurred close by in 1945”, said Dr Fischer. “Based on several indicators, we postulated that the earthquake led to the fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean.” The tremor was recorded at magnitude 8.1 – magnitude 9 is about as bad as an earthquake can be – and seismic waves would have raced through the seabed at colossal speeds, quite enough to shake loose any brittle chemical structures in the seabed. The researchers estimate that the release of methane from that location since that one event could be conservatively estimated at 7.4 million cubic metres: this is roughly the capacity of 10 large gas tankers.

“…hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins…”

This calculation does not take into account how much escaped during the quake itself, and it holds for only one location. “There are probably even more sites in the area that had been affected by the earthquake”, said Dr Fischer. Such research is another reminder of the complexity of the planet’s climate system. Methane hydrates can be considered as a form of fossil fuel: decayed plant material from millions of years ago, trapped in the mud under the pressing weight of the sea. Climate scientists have for decades worried about the fragility of these hydrates – as the world warms, they are likely to be released in huge quantities from the Arctic seabed, for instance – but this is the first evidence that natural rather than human-triggered cataclysms could make a serious difference to the global carbon budget. The lesson is that scientists now have to take such processes into account as they try to calculate the carbon budget for the planet – the quantities of greenhouse gases released into the atmosphere, the volumes subsequently absorbed by plants and then incorporated into sediments. “We now provide a new mechanism of carbon export that had not been considered before”, said Dr Fischer, and with his co-authors he pushes the message home in the research paper. “We therefore suggest that hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins.” – Climate News Network

FOR IMMEDIATE RELEASE Methane is a potent greenhouse gas which in the short term is a much greater threat to global temperatures than carbon dioxide. Now researchers think it can be released by earthquakes. LONDON, 31 July – And here’s another shuddering twist to the horror story that is climate change: even earthquakes may play a role. Large quantities of methane may have escaped during a violent earthquake that shook the floor of the Arabian Sea in 1945, according to German and Swiss researchers. David Fischer of the University of Bremen and colleagues from the Alfred Wegener Institute in Bremerhaven and the ETH in Zurich explored the region in a research ship in 2007, and began to examine cores of sediment from the seabed. One core, from just 1.6 metres below the seabed, contained methane hydrate – an ice-like mixture of methane and water –  and the other did not. But, the researchers report in Nature Geoscience, both cores carried subtle chemical evidence that at some point in the past dramatic quantities of methane or natural gas had actually flowed through the sediments beneath the Arabian Sea. Since the methane would move as a gas, there is only one direction it could go: bubbling upwards through the sea into the atmosphere. And since methane is a potent greenhouse gas – at least 23 times more potent than carbon dioxide – such escapes could be significant. “We started going through the literature and found that a major earthquake had occurred close by in 1945”, said Dr Fischer. “Based on several indicators, we postulated that the earthquake led to the fracturing of the sediments, releasing the gas that had been trapped below the hydrates into the ocean.” The tremor was recorded at magnitude 8.1 – magnitude 9 is about as bad as an earthquake can be – and seismic waves would have raced through the seabed at colossal speeds, quite enough to shake loose any brittle chemical structures in the seabed. The researchers estimate that the release of methane from that location since that one event could be conservatively estimated at 7.4 million cubic metres: this is roughly the capacity of 10 large gas tankers.

“…hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins…”

This calculation does not take into account how much escaped during the quake itself, and it holds for only one location. “There are probably even more sites in the area that had been affected by the earthquake”, said Dr Fischer. Such research is another reminder of the complexity of the planet’s climate system. Methane hydrates can be considered as a form of fossil fuel: decayed plant material from millions of years ago, trapped in the mud under the pressing weight of the sea. Climate scientists have for decades worried about the fragility of these hydrates – as the world warms, they are likely to be released in huge quantities from the Arctic seabed, for instance – but this is the first evidence that natural rather than human-triggered cataclysms could make a serious difference to the global carbon budget. The lesson is that scientists now have to take such processes into account as they try to calculate the carbon budget for the planet – the quantities of greenhouse gases released into the atmosphere, the volumes subsequently absorbed by plants and then incorporated into sediments. “We now provide a new mechanism of carbon export that had not been considered before”, said Dr Fischer, and with his co-authors he pushes the message home in the research paper. “We therefore suggest that hydrocarbon seepage triggered by earthquakes needs to be considered in local and global carbon budgets at active continental margins.” – Climate News Network