The moon controls the release of methane in Arctic Ocean

https://www.sciencedaily.com/releases/2020/12/201214104716.htm

Date:December 14, 2020Source:UiT The Arctic University of NorwaySummary:The moon controls one of the most formidable forces in nature – the tides that shape our coastlines. Tides, in turn, significantly affect the intensity of methane emissions from the Arctic Ocean seafloor. High tides may even counter the potential threat of submarine methane release from the warming Arctic.Share:    FULL STORY


It may not be very well known, but the Arctic Ocean leaks enormous amounts of the potent greenhouse gas methane. These leaks have been ongoing for thousands of years but could be intensified by a future warmer ocean. The potential for this gas to escape the ocean, and contribute to the greenhouse gas budget in the atmosphere, is an important mystery that scientists are trying to solve.

The total amount of methane in the atmosphere has increased immensely over the past decades, and while some of the increase can be ascribed to human activity, other sources are not very well constrained.

A recent paper in Nature Communications even implies that the moon has a role to play.

Small pressure changes affect methane release

The moon controls one of the most formidable forces in nature — the tides that shape our coastlines. Tides, in turn, significantly affect the intensity of methane emissions from the Arctic Ocean seafloor.

“We noticed that gas accumulations, which are in the sediments within a meter from the seafloor, are vulnerable to even slight pressure changes in the water column. Low tide means less of such hydrostatic pressure and higher intensity of methane release. High tide equals high pressure and lower intensity of the release” says co-author of the paper Andreia Plaza Faverola.

“It is the first time that this observation has been made in the Arctic Ocean. It means that slight pressure changes can release significant amounts of methane. This is a game-changer and the highest impact of the study.” Says another co-author, Jochen Knies.

New methods reveal unknown release sites

Plaza Faverola points out that the observations were made by placing a tool called a piezometer in the sediments and leaving it there for four days.

It measured the pressure and temperature of the water inside the pores of the sediment. Hourly changes in the measured pressure and temperature revealed the presence of gas close to the seafloor that ascends and descends as the tides change. The measurements were made in an area of the Arctic Ocean where no methane release has previously been observed but where massive gas hydrate concentrations have been sampled.

“This tells us that gas release from the seafloor is more widespread than we can see using traditional sonar surveys. We saw no bubbles or columns of gas in the water. Gas burps that have a periodicity of several hours won’t be identified unless there is a permanent monitoring tool in place, such as the piezometer.” Says Plaza Faverola

These observations imply that the quantification of present-day gas emissions in the Arctic may be underestimated. High tides, however, seem to influence gas emissions by reducing their height and volume.

“What we found was unexpected and the implications are big. This is a deep-water site. Small changes in pressure can increase the gas emissions but the methane will still stay in the ocean due to the water depth. But what happens in shallower sites? This approach needs to be done in shallow Arctic waters as well, over a longer period. In shallow water, the possibility that methane will reach the atmosphere is greater.” Says Knies.

May counteract the temperature effects

High sea-level seems thus to influence gas emissions by potentially reducing their height and volume. The question remains whether sea-level rise due to global warming might partially counterbalance the effect of temperature on submarine methane emissions.

“Earth systems are interconnected in ways that we are still deciphering, and our study reveals one of such interconnections in the Arctic: The moon causes tidal forces, the tides generate pressure changes, and bottom currents that in turn shape the seafloor and impact submarine methane emissions. Fascinating!” says Andreia Plaza Faverola

The paper is the result of a collaboration between CAGE, Centre for Arctic Gas Hydrate, Environment and Climate at UiT The Arctic University of Norway, and Ifremer under the project SEAMSTRESS — Tectonic Stress Effects on Arctic Methane Seepage

‘Sleeping giant’ Arctic methane deposits starting to release, scientists find

Exclusive: expedition discovers new source of greenhouse gas off East Siberian coast has been triggered

Jonathan Watts Global environment editor @jonathanwatts

Tue 27 Oct 2020 11.40 EDTLast modified on Wed 28 Oct 2020 00.36 EDT

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Researchers worry that the Laptev Sea findings may signal a new climate feedback loop has been triggered.
 Researchers worry that the Laptev Sea findings may signal a new climate feedback loop has been triggered. Photograph: Markus Rex/Alfred-Wegener-Institut

Scientists have found evidence that frozen methane deposits in the Arctic Ocean – known as the “sleeping giants of the carbon cycle” – have started to be released over a large area of the continental slope off the East Siberian coast, the Guardian can reveal.

High levels of the potent greenhouse gas have been detected down to a depth of 350 metres in the Laptev Sea near Russia, prompting concern among researchers that a new climate feedback loop may have been triggered that could accelerate the pace of global heating.

The slope sediments in the Arctic contain a huge quantity of frozen methane and other gases – known as hydrates. Methane has a warming effect 80 times stronger than carbon dioxide over 20 years. The United States Geological Survey has previously listed Arctic hydrate destabilisation as one of four most serious scenarios for abrupt climate change.

The international team onboard the Russian research ship R/V Akademik Keldysh said most of the bubbles were currently dissolving in the water but methane levels at the surface were four to eight times what would normally be expected and this was venting into the atmosphere.

“At this moment, there is unlikely to be any major impact on global warming, but the point is that this process has now been triggered. This East Siberian slope methane hydrate system has been perturbed and the process will be ongoing,” said the Swedish scientist Örjan Gustafsson, of Stockholm University, in a satellite call from the vessel.Quick guide

Methane and the Arctic

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The scientists – who are part of a multi-year International Shelf Study Expedition – stressed their findings were preliminary. The scale of methane releases will not be confirmed until they return, analyse the data and have their studies published in a peer-reviewed journal.

But the discovery of potentially destabilised slope frozen methane raises concerns that a new tipping point has been reached that could increase the speed of global heating.

The Arctic is considered ground zero in the debate about the vulnerability of frozen methane deposits in the ocean.

With the Arctic temperature now rising more than twice as fast as the global average, the question of when – or even whether – they will be released into the atmosphere has been a matter of considerable uncertainty in climate computer models.

The 60-member team on the Akademik Keldysh believe they are the first to observationally confirm the methane release is already under way across a wide area of the slope about 600km offshore.

Scientists at work on the test cruise Electra 1, prior to the Akademik Keldysh expedition.
 Scientists at work on the test cruise Electra 1, prior to the Akademik Keldysh expedition. Photograph: ISSS2020

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At six monitoring points over a slope area 150km in length and 10km wide, they saw clouds of bubbles released from sediment.

At one location on the Laptev Sea slope at a depth of about 300 metres they found methane concentrations of up to 1,600 nanomoles per litre, which is 400 times higher than would be expected if the sea and the atmosphere were in equilibrium.

Igor Semiletov, of the Russian Academy of Sciences, who is the chief scientist onboard, said the discharges were “significantly larger” than anything found before. “The discovery of actively releasing shelf slope hydrates is very important and unknown until now,” he said. “This is a new page. Potentially they can have serious climate consequences, but we need more study before we can confirm that.”

The most likely cause of the instability is an intrusion of warm Atlantic currents into the east Arctic. This “Atlantification” is driven by human-induced climate disruption.

The end of the Arctic as we know it

 Read more

The latest discovery potentially marks the third source of methane emissions from the region. Semiletov, who has been studying this area for two decades, has previously reported the gas is being released from the shelf of the Arctic – the biggest of any sea.

For the second year in a row, his team have found crater-like pockmarks in the shallower parts of the Laptev Sea and East Siberian Sea that are discharging bubble jets of methane, which is reaching the sea surface at levels tens to hundreds of times higher than normal. This is similar to the craters and sinkholes reported from inland Siberian tundra earlier this autumn.

Temperatures in Siberia were 5C higher than average from January to June this year, an anomaly that was made at least 600 times more likely by human-caused emissions of carbon dioxide and methane. Last winter’s sea ice melted unusually early. This winter’s freeze has yet to begin, already a later start than at any time on record.

Exclusive: expedition discovers new source of greenhouse gas off East Siberian coast has been triggered

https://www.theguardian.com/science/2020/oct/27/sleeping-giant-arctic-methane-deposits-starting-to-release-scientists-find

Jonathan Watts Global environment editor @jonathanwatts

Tue 27 Oct 2020 11.40 EDTLast modified on Wed 28 Oct 2020 00.36 EDT

Animal Agriculture and Its Negative Impact on Climate Change

https://sentientmedia.org/animal-agriculture-climate-change/

One of the most overlooked factors of accelerated climate change is animal agriculture. Could changes to the human diet help us slow down the climate crisis?Reading Time: 6 minutes

Animal agriculture has long left its mark upon the earth. Forests have fallen and grasslands trampled in favor of crops and pastureland. Now, however, this sector’s impacts are being felt in the atmosphere – carrying troubling implications for every living thing on the planet.

The agriculture sector is one of the biggest drivers of anthropogenic – meaning human-caused – climate change. Animal agriculture, which sees the raising and processing of ruminants, poultry, and marine life, accounts for some of the biggest sources of greenhouse gasses. Global temperatures rise as forest cover decreases, and oceans warm as they absorb ever-more carbon dioxide. 

Yet there are solutions to these problems – among which is the adoption of plant-based diets. It is not too late for the world to take action against the perils of a changing climate, but time for action is now. 

How Does Animal Agriculture Affect The Environment

Practicing agriculture does not necessarily come naturally to us as a species. For much of human prehistory, people lived in societies oriented around hunting and gathering. The earliest signs of agriculture can be dated at around 12,000 years ago, yet since the dawn of the Industrial Revolution, agriculture has taken on an entirely new face, adopting intensive practices such as concentrated animal feeding operations (CAFOs) which foster truly heartbreaking conditions for farmworkers, animals, and surrounding communities alike. 

Called humanity’s greatest mistake by some due to the resulting hard labor, diminished nutrition, and social inequality brought by agriculture, this system of food production now presents the world with a new quandary: environmental destruction on scales that can no longer be ignored. 

CAFOs produce enormous amounts of waste, which collect in vast open-air lagoons that can be breached by extreme weather events or gradually seep into groundwater. Water pollution from CAFOs can cause algal blooms which can devastate entire marine ecosystems. Air pollution is generated from CAFOs as manure is vaporized, sending toxic wafts through the air to surrounding communities. 

Vast fields of monocrops also cause a host of environmental effects, including air pollution. Pesticides and herbicides are sprayed in liberal amounts, which can cause a host of debilitating illnesses, including cancers, for farmworkers and surrounding communities. Soil depletion is also a serious looming issue. Monocropping, along with the overuse of agrochemicals including synthetic fertilizers like nitrogen and phosphorus, are denying fields a fallow period or crop rotation has the effect of leeching soils of their nutrients. These practices render soils far less productive over time. It takes hundreds, if not thousands, of years for soils to become abundantly fertile again. 

Impact Of Animal Agriculture On Climate Change

Out of all the human activities that cause climate change, agriculture is one of the biggest contributors. Estimates as of 2020 put the sector’s global contributions at 37 percent. Below are a few key factors accounting for climate change emissions resulting from human-cased agriculture. 

Land Use

A full 50 percent of the world’s livable land – meaning land that is ice-free and fertile – is being used for agriculture. No other human activity takes up more space. In contrast, all urban areas account for around one percent of livable land use. A whopping 77 percent of agricultural land is dedicated to raising animals, including grazing and the land used to grow their feed, including vast monocrops of species like corn and soy. Surprisingly, this huge expenditure of resources and land use provides only 18 percent of the world’s calories. 

Land used for any type of agriculture – be it livestock or crops meant for people or animals – is brought under cultivation by clearing forests and grasslands, which are carbon sinks due to their abilities to absorb carbon. Currently, forests consume roughly a quarter of all anthropogenic CO2, yet the more forests are slashed and burned to make way for pastureland or monocrops, the less carbon will be absorbed, resulting in accelerated climate change.

Livestock

Farmed animals – referred to as livestock – generate over 14 percent of all anthropogenic emissions, with estimated totals hovering around seven gigatonnes of carbon dioxide emitted every year. The bulk of these emissions are due to raising cattle for meat and dairy, contributing 60 percent of total livestock emissions.  These emissions are thanks to the vast amounts of resources cows consume, the land they require for pasture (in the case of beef cattle), and other manure they produce. Cow manure contains nitrous oxide and methane, the latter being one of the most potent greenhouse gasses due to its outsized ability to absorb heat. 

Fisheries

Marine life, including fish, shellfish, shrimp, and other animals are taken from the seas in astronomical numbers. Nets, some of which are large enough to contain 12 jumbo jet airplanes, are dragged through the water or across the bottom of the seafloor, capturing everything in their path. Direct fishing activity, plus the energy expended to transport, process, and refrigerate carcasses amounted to an estimated total of 179 million tonnes of greenhouse gasses in 2011 – and this number likely will continue to grow as demand for seafood increases. 

How Do Greenhouse Gases Affect the Climate?

In greenhouses designed to grow plants, the transparent glass structure allows sunlight into the greenhouse while preventing heat from escaping. The earth’s atmosphere functions in a similar way, with gas molecules acting like the glass. Certain gases are more effective at absorbing heat than others; these include methane, nitrous oxide, and perhaps the most infamous, carbon dioxide. These three gasses are among the main culprits of climatic warming and change caused by human activities. 

One of the biggest drivers of global warming has been the release of carbon into the atmosphere due to the burning of fossil fuels such as natural gas, oil, and coal, which power many aspects of modern life. Even electric cars, which run on batteries and do not themselves generate carbon emissions, draw electricity from grids still run on fossil fuels (although the goal of using 100% renewable energy for electric grids is more achievable than ever). When carbon released from fossil fuel burning is released into the atmosphere, it binds with oxygen and forms carbon dioxide and begins trapping heat in the atmosphere. Because carbon emissions make up the vast majority (81 percent, as of 2018) of total greenhouse gases, they pose one of the gravest threats to climate stability. 

Although carbon is the greatest emitted by volume, other greenhouse gases can be much more potent. For example, one ton of nitrous oxide – emitted by agricultural processes including the use of nitrogen fertilizers in crop production – is equivalent to nearly 300 tons of carbon dioxide.

Methane is approximately 30 times more potent in its ability to absorb and trap heat in the atmosphere than carbon dioxide.

Can Greenhouse Gas Emissions From Animal Agriculture Be Reduced?

By far, the most effective way to reduce the animal agriculture sector’s greenhouse gas footprint is to significantly reduce, and eventually eliminate animal agriculture. While this might sound “extreme”, it is the state of industrial animal agriculture – characterized by inhumane CAFOs, waste lagoons teeming with pathogens and antibiotics, and requiring enormous land and feed inputs – which is even more extreme

This is not to say that eliminating animal agriculture is something easily accomplished. Demand will have to decrease, thanks to people turning to plant-based diets. The ease of adopting these diets is not the same for everyone, however. Many lower-income neighborhoods in the United States are classified as food deserts, where a lack of grocery stores forces people to endure extremely limited options, such as gas stations or fast-food restaurants. 

People in nations like the United States who do not live in food deserts bear much of the responsibility for reducing demand for animal products. Fortunately, plant-based options abound to replace animals in a wide range of products, from cheese to milk to burgers and sausages. Beyond Meat and Impossible Foods are two of the leading companies in the plant-based meat sector, helping the idea of plant-based meats go mainstream and helping people understand that it’s possible to achieve the BBQ-worthy tastes without the climate side-effects. Plant-based meats use up to 99 percent less land and emit up to 90 percent fewer greenhouse gas emissions.

Animal Agriculture And Global Warming

Flying in planes or driving SUVs have long been understood as having negative impacts on the global climate. While these are certainly deserving of critique and change, the agriculture sector deserves time in the spotlight. If industrial agriculture continues to grow unchecked, global warming will increase – with potentially disastrous impacts, the beginnings of which are being felt today. Methane, produced by livestock including sheep, goats, and cows, is a greenhouse gas with a terrific ability to trap heat in the atmosphere. The agriculture industry is responsible for fully 40 percent of the total anthropogenic greenhouse gas emissions.

In order to curb global warming, and keep the global temperature increase below 1.5 degrees Celsius, the United Nations Intergovernmental Panel on Climate Change says that global emissions will need to be reduced by around 40 to 50 percent. According to the U.N., the only way to achieve these reductions is to drastically increase forested land – which means reclaiming land currently under cultivation and to stop intrusions into existing forests.  

Conclusion

Due to its profound impacts on the climate and environment around the world, agriculture may well be humanity’s gravest mistake – because it may be our undoing. Unless greenhouse gas emissions are seriously curbed, the world is going to be a far more difficult place to endure. Reducing demand for animal agriculture and adopting a plant-based diet is among the most important actions any individual can make. 

Burger King’s New Low-Methane Burgers Aren’t Going to Save Us

https://sentientmedia.org/burger-king-low-methane-burger-arent-going-to-save-us/?fbclid=IwAR2k-gtwOk1QhNXBIRb0JfzHujVSAil5cEsr_uQwCMVqfTRI4U39Pcr6DbY

The meat industry is under intense scrutiny for its climate impact, with beef singled out as the biggest culprit. But if you want to save the planet, opt for the salad. It’s that simple.Reading Time: 5 minutes

July is over and with it Burger King’s short-lived but much-touted experiment with low-methane burgers. Two weeks ago, an ad for burgers made from cows fed with lemongrass to reduce the climate impact of their burps went viral, garnering the company free advertising by virtually all major media networks as well as some well-deserved criticism. Now the ad, like all things viral, is on its way to being forgotten, and the allegedly low-methane burger will fade off menus. But the whole episode can tell us a lot about how meat producers are greenwashing their products.

Burger King, like other companies that sell beef, is beginning to feel the heat from global climate change, and they are responding to the climate crisis by presenting unsustainable products as environmentally friendly. Don’t be fooled. Any way you slice it, beef’s climate cost can’t be reduced with marginal fixes like lemongrass.

The viral ad announcing Burger King’s new “low emissions” burger is a joke—and a fart joke at that. It opens with a boy styled in a white cowboy suit with a guitar in hand. He kicks open a saloon door embedded in a gassy bovine rectum (yes, really!) and, backed by a chorus of two-stepping tykes, he honky-tonks his way through psychedelic pastures and rolling hills among farting woodcut cows. The kids dance past melting icebergs and above billowing methane clouds, before donning hats decorated with lemongrass tufts. “Since we are part of the problem, we’re working to be part of the solution,” Burger King concludes. But they’re only half right!

The scene sure is something, but the science is dubious. Cows mostly burp, not fart methane. That Burger King is sniffing the wrong end of the cow is, at best, a joke and, regardless, a reminder that the company is in the burger business and not science business. The 33 percent methane reduction the company promises by switching to “low emissions” beef is also misleading. The claim is not based on peer-reviewed science, and the alleged reduction only accounts for emissions in the final “fattening” stage of production—as opposed to a cow’s entire life—meaning its total contribution to reducing greenhouse gasses (GHGs) is probably closer to 3-4 percent. Tellingly, Burger King released the ad on the same day that scientists announced that global methane emissions have grown dramatically in the past two decades.

Burger King’s ad is just the latest example of a growing trend of greenwashing in beef marketing. Beef industry organizations such as the National Cattlemen’s Beef Association and the Beef Checkoff Program regularly issue press releases and factsheets touting the “sustainability” of beef, while major beef producers publicly swear they’re cutting GHG emissions. And it seems to be working, with some major media organizations lapping up the message that “Low-methane meat is a thing now.”

It’s easy to see why Big Beef is working hard to cast their product as climate-friendly. Over the past two decades, the meat industry has come under intense scrutiny for its climate impact, with beef singled out as the biggest culprit. Livestock—between methane emissions, the production of feed, and other production costs—contribute about 15 percent of total global GHGs and, since cattle make up 40 percent of that, cattle alone make up about 6 percent of humanity’s GHG footprint. In the U.S., cattle represent 3.7 percent, or about 240,500,000 metric tons, of GHGs per year.

The average American eats about 57 pounds of beef per year, and between the domestic and export market, the U.S. produces around 27 billion pounds annually. That’s 33.6 million head of cattle, with just four enormous producers—Cargill, Tyson Foods, JBS USA, and National Beef—accounting for 85 percent of the supply. These cattle have a massive environmental footprint and require an enormous amount of land.

Beef advocates are mustering a defense of their climate impact under the slogan, “It’s not the Cow. It’s the How.” Some acknowledge the impact of large-scale, feedlot-fed beef, but encourage smaller-scale “regenerative” agriculture. These advocates contend that cattle grazing stimulates carbon sequestration in soils and that cows’ manure can substitute for carbon-intensive synthetic fertilizers, thereby offsetting methane emissions and making cattle GHG-neutral. Evangelists of regenerative agriculture argue that it could become the dominant form of cattle production. This is unlikely. Not only is the scientific community not sold on its climate benefits, but the system cannot be scaled up to supply low-cost beef to low-cost retailers and restaurants like Burger King. According to Matthew Hayek, Ph.D., who studies the environmental impacts of our food system at New York University, there simply isn’t enough land in the U.S. to graze all those cows.

For the commodity beef producers, meanwhile, their only option is to find ways of cutting emissions within existing production chains. Increasingly, they have resorted to changing cows’ diets to try and reduce their carbon footprint. Studies have shown, for instance, that feeding cows seaweed can potentially reduce methane emissions by upwards of 60 percent. The industry has been quick to use these studies to boast that they are part of the solution to global climate change.

But these methane reductions are theoretical, marginal, and impractical. Globally, most cows eat a standard diet. It is unclear that feed additives can be produced affordably at scale. Enormous monocultures of algae required for cattle feed may also have serious ecological costs. And, like Burger King’s sustainability claims, these solutions focus primarily on the “finishing” stage of production. To put it simply, there’s no such thing as a zero-emissions cow, and even a reduced-emissions cow produces far more GHGs than other protein sources. And none of this addresses the cattle industry’s other ecological impacts, like deforestation and contamination of waterways. This solution is also incompatible with regenerative agriculture: feed additives require standardization and scaled mass confinement, exactly the thing regenerative grazing is supposed to eliminate.

Big Beef is trying to put lipstick on the, er, cow. The emerging scientific consensus is that beef production needs to be massively reduced globally, and diets need to adapt if we’re to keep food production within planetary limits.

Meanwhile, the entire meat industry now faces heightened criticism unrelated to GHGs. Recently, we’ve seen packers strong-arm vulnerable workers into COVID-19 “superspreader” slaughterhouses. We’ve seen the industry respond to production bottlenecks by “depopulating” (industry-speak for killing) millions of farm animals. We’ve seen hurricanes dump millions of gallons of livestock manure into drinking water. Now add this to the butcher’s bill: agriculture is responsible for half of all zoonotic disease and a full quarter of all infectious diseases since 1940.

This moment of crisis should be a moment of transformation, not greenwashing. Whatever consumers choose to order at Burger King (we recommend the meat-free, actually low-impact Impossible Burger), we should not applaud solutions that trivialize the scale and nature of the problem. Big Beef must be regulated to ensure that its workers are safe and that the price of its product reflects its true cost to the public, workers, future generations, and animals. It should be taxed, and those monies should be invested in public projects aimed at environmental sustainability, GHG reduction, and the development of cellular agriculture that would allow consumers to eat beef without the cows and their burps. And, ultimately, industrial animal agriculture should be eliminated.

In the meantime, being a conscientious consumer is hard. We all make compromises. But if you think that eating Burger King’s “low emissions” burger is a real solution, you’re the sucker. Want to save the planet? Opt for the salad. It’s that simple.

Soaring methane emissions threaten to put climate change goals out of reach

https://www.nbcnews.com/science/environment/soaring-methane-emissions-threaten-put-climate-change-goals-out-reach-n1233831

Global emissions of methane, a potent greenhouse gas, have soared over the past decade, according to two new studies that tracked growing sources of the odorless, colorless gas.

Image:

Environmentalists say that agriculture and transportation activities have boosted the amount of Methane in Earth’s atmosphere.Dago Galdieri / Bloomberg via Getty ImagesJuly 14, 2020, 4:17 PM PDTBy Denise Chow

Earth’s climate crisis is starting to look even worse than scientists had feared — in part because of just how much meat we eat and how we get around.

Global emissions of methane, a potent greenhouse gas, have soared over the past decade, according to two new studies that tracked growing sources of the odorless, colorless gas. The increased methane, combined with carbon dioxide and other greenhouse gases, could warm Earth’s atmosphere by 3 to 4 degrees Celsius before the end of this century — significantly above the levels that scientists have warned could be catastrophic for millions of people around the world.

“This completely overshoots our budget to stay below 1.5 to 2 degrees of warming,” said Benjamin Poulter, a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Poulter is an author on both studies published Tuesday, one in the journal Earth System Science Data and the other in the journal Environmental Research Letters.

Poulter and his colleagues found that since 2000, the biggest increases in methane emissions came from agricultural activities — particularly from livestock, such as cattle and sheep — and the fossil fuel industry, which includes coal mining as well as oil and gas production.

Human activities account for about 60 percent of global methane emissions, according to the researchers. Agriculture makes up roughly two-thirds of that, with fossil fuel production and use contributing most of the rest.

JULY 14, 202002:01

In the new studies, researchers analyzed methane emissions from 2000 through 2017 — the latest year for which complete global methane figures are available — and found that a record 600 million tons of methane were released into the atmosphere in 2017. Annual emissions of methane have also increased by 9 percent since the early 2000s, a pace that could contribute to more than 2 degrees Celsius of global warming by 2100.

report released by the Intergovernmental Panel on Climate Change in October 2018 highlighted that the planet has already warmed by 1 degree Celsius since the 19th century; it used 1.5 degrees of warming above pre-industrial levels as a threshold beyond which the effects of climate change, including extreme heat and sea-level rise, become life-threatening for tens of millions of people around the world.

Another author on both studies, Rob Jackson, a professor of Earth system science at Stanford University, said the amount of methane released into the atmosphere since 2000 is roughly equivalent to adding 350 million more cars on the road.

In 2017, methane emissions from agriculture rose by nearly 11 percent from the 2000-06 average, while methane from fossil fuels jumped by nearly 15 percent compared to the early 2000s.

Methane is released into the atmosphere when coal, oil and natural gas are mined and transported, but microbes also emit it in low-oxygen environments.

“Any place where there is little to no oxygen — wetlands, rice paddies, landfills, the gut of a cow — are all sources of methane,” Jackson said.

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Overall, methane makes up a much smaller percentage of global greenhouse gas emissions than carbon dioxide does, but it’s of particular concern to scientists because methane’s molecular structure makes it more readily able to absorb thermal radiation.

“Methane doesn’t last as long in the atmosphere as carbon dioxide, but it’s much more efficient at trapping heat than carbon dioxide,” Poulter said, which makes the gas a key factor in global warming.

To curb methane emissions, countries need to reduce their reliance on fossil fuels, in addition to reducing the number of harmful leaks from pipelines and wells, Jackson said.

Scientists are also studying how to minimize methane emissions in agricultural practices, such as altering water levels in rice paddies and experimenting with changes in the diets of cattle and sheep to reduce the amount of methane belched from their digestive systems. Burger King recently announced that it is adding lemongrass to the diet of its cows to reduce methane emissions with a lower-carb feeding regimen.

But slowing greenhouse gas emissions will also require bigger changes in human behavior, Jackson said.

“Diet matters,” Jackson said. “Here in the U.S., we have one of the highest rates of red meat consumption in the world. We don’t have to stop eating red meat necessarily, but eating less meat or eating more fish and chicken instead of beef will reduce emissions, too.”

And while the coronavirus pandemic is expected to result in significant decreases in carbon dioxide emissions in 2020 — primarily from economic slowdowns and lockdowns that sharply reduced air travel and other transportation — similar declines are not anticipated with methane.

“Our farmers are still producing food, oil and gas production hasn’t fallen much yet, and methane plays only a tiny part in the transportation sector,” Jackson said. “So while we may see a small decrease this year because of the coronavirus, methane emissions over the last decade are marching upward. And at this rate, we won’t see peak methane emissions any time soon.”

Don’t have a cow, but Big Dairy’s climate footprint is as big as the UK’s

dairy cows with planetGrist
DOWNSIDE OF DAIRY

https://grist.org/food/dont-have-a-cow-but-big-dairys-climate-footprint-is-as-big-as-the-uks/

If dairy cows were a country, they would have the same climate impact as the entire United Kingdom. That’s according to a new analysis from the Institute for Agriculture and Trade Policy (IATP), which considered the combined annual emissions from the world’s 13 largest dairy operations in 2017, the most recent year for which data was available.

The institute’s report follows up on a similar analysis the organization undertook for 2015. That year, the IATP found that the five largest meat and dairy companies combined had emissions portfolios greater than those of some of the world’s largest oil companies, like ExxonMobil and Shell. Most of the emissions were from meat, but this latest report finds that dairy remains a significant and growing source of emissions: In the two years between reports, the 13 top dairy companies’ emissions grew 11 percent — a 32.3 million metric ton increase in greenhouse gases equivalent to the emissions that would be released by adding an extra 6.9 million cars to the road for a year.

Dairy emissions come mostly from the cows themselves — specifically, from their notorious burps. Fermentation processes in cows’ stomachs produce the byproduct methane, which doesn’t stick around in the atmosphere as long as carbon dioxide but absorbs more heat. The Intergovernmental Panel on Climate Change says methane from ruminants like cows are an important contributor to the increase of atmospheric methane levels.

Shefali Sharma, director of IATP Europe and author of the new study, said it was staggering to see dairy’s increase in emissions, especially since it occurred in the two years after the Paris Agreement was negotiated. “We’re supposed to be going in the opposite direction,” she told Grist.

The report points to consolidation and rising production as the main culprits for the increased emissions. From 2015 to 2017, the 13 companies used mergers and acquisitions to expand geographically and subsume smaller farms. As the companies got bigger, their production increased by 8 percent, which led to the emissions hike.

The dairy industry takes issue with the report’s framing, chalking the emissions increase up to an “accounting change.” As smaller farms were absorbed by the big companies, the industry argued, their production and greenhouse gas emissions got wrapped into the 13 largest producers’ emissions numbers.

“These are not new emissions,” the International Dairy Federation and the Global Dairy Platform said in a joint statement responding to the IATP report.

At the same time, the companies haven’t done much to help researchers figure out their net greenhouse gas output; none are required to disclose their climate impacts, and only five of the 13 publicly report their emissions. Zero of them have committed to reducing the overall emissions footprint of their dairy supply chains.

“There’s no transparency, not even basic production numbers,” Sharma told Grist. To calculate the companies’ emissions for the IATP report, Sharma used production estimates calculated by the IFCN, a dairy research network, and calculated each firm’s associated carbon emissions using an accounting method established by the U.N.’s Food and Agriculture Organization (FAO).

Instead of focusing on total emissions, the biggest dairy producers have tried to paint a different picture of their climate impact. The IATP report says companies like Danone have drawn attention to something they call “emissions intensity”: the greenhouse gas emissions associated with each liter of milk.

According to Sharma, focusing on emissions intensity allows dairy producers to make more milk, more efficiently, and then say they’re reducing their climate impacts. Even if the total number of cows increases (which it has), and even if cumulative emissions go up (which they have), the industry can mask these planet-warming effects by emphasizing greater greenhouse gas efficiency per unit of milk produced. For example, a 2019 report from the FAO — which was co-authored by the Global Dairy Platform — says the dairy industry’s emissions intensity, measured in greenhouse gas per kilogram of milk, declined by nearly 11 percent from 2005 to 2015.

However, the same section of the report also says that “increased production efficiency is typically associated with a higher level of absolute emissions (unless animal numbers are decreasing).” The Global Dairy Platform acknowledged this in its statement responding to the IATP report, saying that as the industry increased its production by 30 percent globally between 2005 and 2015, it could have increased its absolute emissions by 38 percent. But because of “improvements” to increase efficiency, absolute emissions only rose by 18 percent.

Sharma says it’s a distraction to focus on emissions intensity. “You’ve got to reduce your overall emissions, it doesn’t matter about your ‘per unit,’” she told Grist. To her, that means producing less milk — with fewer cows.

On top of the climate change impacts, the IATP report also highlights the impacts of big dairy operations on small- and medium-sized farms. In each of the world’s four main dairy-producing regions — North America, Europe, India, and New Zealand — bankruptcy and farm losses increased between 2015 and 2017.

In the United States, 94 percent of family farms in dairy have closed since the 1970s. Between 2014 and 2019, Wisconsin — America’s self-proclaimed “Dairyland” — lost more than a quarter of its 10,000 dairy farms.

In the absence of governmental supply management policies, the mega-dairies that incorporate these small farms are able to flood the market with milk, often for export, driving down dairy prices and crowding out small holders or reducing their income. They are also often unaccountable for environmental pollution, from manure runoff from fields to spills from manure storage lagoons to air pollution.

To remediate the situation, Sharma doesn’t think people need to give up milk; she just wants the dairy industry to radically change its business model. “You could totally still have farms with livestock on them,” she told Grist. “It just wouldn’t be the vast quantity of livestock that we see today.”

According to the IATP report, a comprehensive set of government regulations to decrease dairy production would come with all sorts of co-benefits — for farmers and the climate. A supply management system to lower dairy output could allow companies to pay farmers better wages and allow the government to reinvest in less emissions-intensive systems of small-scale farming. These reforms could help strengthen rural economies and protect ecological systems. And ending subsidies to the largest dairy operations could free up funds that could go toward support and job training for out-of-work dairy workers.

To enact these policies, Sharma suggests consumers think beyond switching to locally produced dairy or almond milk. “In terms of individual demand, that’s just not going to move the needle,” she said. But calling federal elected officials about agriculture policy might. Holding global dairy corporations accountable is a political challenge, but Sharma is hopeful: “Political change is possible, it’s achievable,” she said. “We just have to create it.”

Agriculture and livestock: Are they victims or perpetrators of climate change?

June 11, 2020 /https://www.thedailystar.net/opinion/news/agriculture-and-livestock-are-they-victims-or-perpetrators-climate-change-1912177
LAST MODIFIED: 01:54 AM, June 11, 2020

Though much of the world is focused on transitioning away from fossil fuels as a way to fight climate change, there are other often overlooked contributors to the conundrum resulting from climate change. Two of them are agriculture and livestock. Sure, they provide us with the food we eat every day. But cumulatively, they are also the second largest contributor to greenhouse gas emissions after fossil fuels.

While the majority of global warming activities give off carbon dioxide, the agricultural sector primarily releases methane, which is a greenhouse gas 28 times as potent as carbon dioxide over a 100-year period. The source is mainly rice that is grown on flooded fields with depleted dissolved oxygen. In the absence of oxygen, organic matter in the soil decomposes and produces methane that escapes into the atmosphere. Rising temperatures would cause rice cultivation to release even more methane.

Another source of methane is ruminants, particularly cows and goats. As part of their digestion cycle, they expel intestinal gases, mostly methane, via belches. Methane can also escape from stored manure and organic waste in landfills. If manure is stored as a liquid or slurry in ponds, tanks or pits, it decomposes anaerobically (in the absence of air) and emits a prodigious amount of methane. However, when handled as a solid or deposited naturally on grassland, manure decomposes aerobically and creates negligible methane emissions. Ruminants, manure and rice cultivation account for almost 25 percent of anthropogenic methane emissions.

One of the methods of reducing methane emissions from rice fields, as suggested by scientists at the World Resources Institute, is to plant rice in a raised bed and flood only the furrows. This method has the potential to cut methane emissions in half.

Controlling methane emissions from ruminants is more difficult than trimming or regulating methane emissions from fossil fuels. A large number of mitigation options—namely, diet manipulation, vaccines, chemical additives and genetic selection—have been proposed. They have different efficiencies in lowering production of intestinal methane.

Methane emissions from manure depend on temperature and storage duration. Results from typical Canadian farms indicate that use of underground manure storage tanks, maintained at lower temperatures, lessens methane emissions. Additionally, farmers found that if they clean the tanks regularly, it took longer for methane-producing organisms to grow back. Consequently, methane emissions decrease substantially.

As for agriculture, according to a report of the United Nations published last year, about 50 percent of the Earth’s cultivable land is dedicated to growing crops for humans and roughly 30 percent is used to grow grain for livestock. Given how much land it takes to grow food to feed livestock, a very vocal segment of environmentalists insist that “meat is heat” and encourage consumers to go vegan.

Moreover, in line with the projected population growth, global demand for food is expected to grow by up to 70 percent in the coming decades. This substantial increase in demand would require clearing more space for agriculture and cattle grazing, so that the per capita threshold of land required for a nation to be self-sufficient in food production could be maintained. Vast swaths of the Amazon Rainforest, along with lands and forests in other places, are already being cleared for growing crops and grazing cattle. If current trends continue, most of our planet’s remaining land and forests would need to be cleared to feed the world.

Deforestation and land degradation indirectly contribute to the negative impacts of atmospheric carbon dioxide. One of the main reasons for this is because forests are natural carbon sinks. They absorb carbon dioxide from the atmosphere and converts it into oxygen that we breathe in. Hence, by cutting down big areas of forest without replacing the trees that are removed, we are causing an inadvertent change in the amount of carbon dioxide in the atmosphere.

Several studies indicate that planting more than two billion acres of trees could remove two-thirds of all the carbon dioxide that human activity has pumped into the atmosphere since the Industrial Revolution. Trees also recharge the water table and create microclimates that increase local rainfall. In addition, deforestation puts biodiversity at risk, further undermining nature’s ability to cope with the impacts of climate, for example absorbing heavy rainfall.

Clearly, agriculture in general, and livestock in particular, contribute considerably to climate change. Nevertheless, climate change is also a major threat to the sustainability of livestock globally. An increase in air temperature as a result of global warming directly affects milk and meat production, reproductive efficiency and health of the animals. Also, excessive heat would reduce their body size and fat thickness.

Agriculture is also highly vulnerable to climate change. It is affecting food security by raising the risks to food supply due to heat waves, drought, flood, storms, soil depletion and desertification. Over the coming dozen years or so, farmers in developing countries, especially in South and Southeast Asia, will be the ones to bear the brunt of global warming, as per a recent report of the Food and Agricultural Organization of the UN.

It could, therefore, be said that agriculture and livestock farming are caught in a vicious cycle that makes them both victims and perpetrators of the harmful effects of climate change. Most of the times when agriculture perpetrates its crimes, it is not even contributing to feeding the ever-increasing world population. Instead, a good portion of the agricultural products are consumed by livestock—mostly bovines—which demonstrates this paradox.

How do we solve this complex problem? The solution obviously requires a coherent and integrated approach to climate change, energy usage and food security. Faced with global warming, competition for scarce resources, and inaction by world leaders, we, the people, have to transform the entire global food system and make it much more resource-efficient while continuously curbing its environmental impacts, including its greenhouse-gas emissions.

We also have to increase yields while curtailing dependence on agrochemicals. Besides, we should minimise food waste, cut down consumption of resource-intensive and greenhouse gas-producing foods, notably meat, and switch to climate-friendly vegetables, such as the nutritionally rich seaweed kelp. Farming kelp is beneficial for the ocean.

Furthermore, employing sustainable practices, like organic agriculture, has enormous potential to help in the fight against global warming, whereas maintaining the status quo with widespread industrial agricultural practices will continue to be terribly detrimental to the climate. In short, making agriculture and livestock industries and all associated activities sustainable is the answer to win the battle against global warming, as well as accelerate the transition to a healthier and more just society.

 

Quamrul Haider is a Professor of Physics at Fordham University, New York.

Scientists lock horns over climate change impact of cattle

https://www.smh.com.au/politics/federal/scientists-lock-horns-over-climate-change-impact-of-cattle-20200602-p54ymo.html

The livestock industry says the standard method of calculating the global warming contribution of methane significantly overstates the impact of cattle and is calling for policy changes that could slash the emissions counted against the industry.

While some scientists are backing the proposed change, others argue it could lead to an overly optimistic assessment of the climate change contribution of the industry, which committed in 2017 to achieve net zero emissions by 2030.

Due to a series of droughts, the national cattle herd has shrunk 12 per cent in the past 20 years.
Due to a series of droughts, the national cattle herd has shrunk 12 per cent in the past 20 years.CREDIT:ALEX ELLINGHAUSEN.

Livestock are the main contributor to agriculture sector emissions. Cows’ gassy burps are loaded with methane, a byproduct of digesting grass. Last year agriculture emissions accounted for 12.9 per cent of Australia’s total greenhouse gas output, down 5.8 per cent as farmers reduced their stock due to drought.

In 1997 the Intergovernmental Panel on Climate Change agreed on a methodology to account for the global warming potential of greenhouse emissions over a 100-year time frame, known as the GWP100.

However, some scientists promote a new accounting methodology known as GWP Star, which counts the global warming potential of greenhouse gases over 20 years.

Methane emissions break down in the atmosphere over 12 years, much quicker than carbon dioxide, which takes 100 years to break down.

Tony Hegarty from the Cattle Council said GWP Star could provide a “more accurate approximation of the actual warming” caused by methane over its lifetime.

“We are prepared to allow the scientists to do the analysis. It’s better for us to call on the government and international community to have a serious conversation. I’m very confident it’s a more accurate approach and it could make a significant difference to our [cattle industry] emissions,” Mr Hegarty said.

The GWP Star method says the greenhouse effect of methane should not be calculated in the same way as carbon dioxide. Under this methodology, when an industry increases above the baseline of emissions starting in 1997, that is counted as growth.

But significantly, a decrease below the 1997 baseline is counted as emission reduction. In this way, when industry emissions fall below the baseline set 23 years ago, it can claim not to be contributing to additional global warming.

Melbourne University agriculture Professor Richard Eckard, who endorses using GWP Star, said the Australian national herd has declined by 12 per cent over 20 years and under GWP Star this would be recognised as net greenhouse gas reduction.

“This calculation shows that livestock in Australia have potentially contributed to a cooling rather than warming, relative to the period prior to 1997,” Professor Eckard said.

However, other scientists say the rate of breakdown doesn’t change the impact of a gas on warming if it’s continually topped up by grazing cows, even while emissions break down.

Australia National University Climate Change Institute director Professor Mark Howden said the atmospheric heating effect of methane “is not fundamentally different to carbon dioxide”.

“There’s a difference in the lifespan of the gases but because there are constant emissions the build-up in the atmosphere is the same,” Professor Howden said.

He said the 20-year accounting time frame also ignores historical emissions.

“GWP Star is trying to compensate for the different lifespan of greenhouse gases, but in doing so it actually grandfathers previous emissions levels (before 1997), which brings all sorts of problems into the system.”

Professor Howden said under GWP Star when an industry reduced its methane emissions by 12 per cent, it may claim to contribute to global cooling and “get a green light”, whereas under the existing GWP100 approach it would still get a red light – just slightly less red.

“These are pretty fundamental differences,” he said.

Detecting methane emissions during COVID-19

https://phys.org/news/2020-06-methane-emissions-covid-.html

Detecting methane emissions during COVID-19
GHGSat uses data from the Copernicus Sentinel-5P satellite to detect emission hotspots in various regions – including the Permian Basin. The image on the left shows the enhanced methane concentrations over the Permian basin, while the image on the right highlights the exact facility in the Permian Basin leaking methane. Credit: GHGSat

While carbon dioxide is more abundant in the atmosphere and therefore more commonly associated with global warming, methane is around 30 times more potent as a heat-trapping gas. Given its importance, Canadian company GHGSat have worked in collaboration with the Sentinel-5P team at SRON Netherlands Institute for Space Research to investigate hotspots of methane emissions during COVID-19.

Carbon dioxide is generally produced by the combustion of fossil fuels, while fossil fuel production is one of the largest sources of methane emissions. According to the World Meteorological Organisation’s State of the Global Climate report last year, current  and methane concentrations represent respectively 150% and 250% of pre-industrial levels, before 1750.

Owing to the importance of monitoring methane, SRON’s and GHGSat’s research teams have been working since early-2019 to detect methane hotspots. The SRON team uses data from the Copernicus Sentinel-5P satellite to detect emissions on a global scale. The GHGSat team then utilises data from GHGSat satellites to quantify and attribute the emissions to specific facilities around the world.

Their work has led to several new hotspots being discovered in 2020, for instance over a coal mine in China. The team have also detected methane emissions over the Permian Basin—the largest oil-producing region in the United States. The team observed concentrations from March-April 2020, compared to the same period as last year in an effort to evaluate the impact of COVID-19 activities on methane emissions.

Detecting methane emissions during COVID-19
GHGSat have worked in close collaboration with the Sentinel-5P team at SRON Netherlands Institute for Space Research to investigate hotspots of methane emissions. The team uses data from the Copernicus Sentinel-5P satellite to detect emissions on a global scale, and then utilises data from GHGSat satellites to quantify and attribute emission to specific facilities around the world. This has led to several new hotspots being discovered including a coal mine in the Shanxi province, China. Credit: contains modified Copernicus Sentinel data (2018, 2020), processed by SRON

An initial look at these data suggest a substantial increase in methane concentrations in 2020, compared to 2019. Claus Zehner, ESA’s Copernicus Sentinel-5P mission manager, says, “An explanation for this could be that as a result of less demand for gas because of COVID-19, it is burned and vented—leading to higher methane emissions over this area.”

Ilse Aben, from SRON, comments, “However, these results are inconclusive when using only Sentinel-5P data in the Permian Basin as the number of observations are limited.”

The spatial distribution of Sentinel-5P concentrations in 2020 and in 2019 both indicate local enhancements of methane concentrations in the Delaware and Midland portions of the basin. But higher-resolution measurements, such as those provided by GHGSat, are needed to attribute these enhancements to specific facilities.

The joint analysis of GHGSat and Sentinel-5P regional  data will continue to explore and quantify how COVID-19 is affecting emissions from the natural gas industry on a regional scale—all the way down to the level of industrial facilities.

Detecting methane emissions during COVID-19
This image shows GHGSat methane concentrations over a coal mine in the Shanxi province, China. Credit: GHGSat

Stephane Germain, CEO of GHGSat, comments, “GHGSat continues to work closely with ESA and SRON’s Sentinel-5P science team. We are advancing the science of satellite measurements of atmospheric trace gases while simultaneously providing practical information to industrial operators to reduce facility-level emissions. GHGSat’s next satellites, scheduled to launch in June and December of this year, will help improve our collective understanding of industrial emissions around the world.”

Eric Laliberté, Director General Utilization from the Canadian Space Agency, says, “The Canadian Space Agency is committed to developing space technologies and supporting innovative missions to better understand and mitigate climate change. The results achieved by GHGSat are already having an impact and we are excited to continue working with GHGSat and ESA to better understand greenhouse gas emissions worldwide.”

Claus adds, “In order to further support the scientific uptake of GHGSat measurements, ESA has organised, together with the Canadian Space Agency and GHGSat, a dedicated Announcement of Opportunity Call that will provide around 5% of the measurement capacity of the upcoming commercial GHGSat-C1, also known as the Iris satellite, to the scientific community.”

The Copernicus Sentinel-5P satellite, with its state-of-the-art instrument Tropomi, can also map other pollutants such as nitrogen dioxide, carbon monoxide, sulphur dioxide and aerosols—all of which affect the air we breathe.


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Methane leak visible from space

Scientists understand cattle not climate villains, but media still missing message

FOR a long time emissions from cattle have been lumped in with emissions from other sources as the same destructive forces for the planet in the global climate change narrative.

However, through research overseen by scientists including Dr Frank Mitloehner (right) from the University of California Davis and Dr Myles Allen from Oxford University, scientific consensus is starting to build around the point that livestock-related greenhouse gases are distinctively different from greenhouse gases associated with other sectors of society (more on this below).

Dr Mitloehner, an internationally recognised air quality expert, explained to the Alltech One virtual conference on Friday night (Australian time) that the concept of accounting for methane according to its Global Warming Potential, as opposed to just its volume of CO2 equivalent, which showed that not all greenhouse gases are created equal, has now made it all the way to the International Panel on Climate Change.

However, despite increasing awareness and understanding at a scientific level, the message has still not been taken up by the mainstream media.

“What I find interesting is that the one missing entity in this whole discussion so far has been the media,” he told Alltech president and CEO Dr Mark Lyons in a live streamed video interview.

“I have not seen any major reporting on this even though it’s such a hot topic.

“I mean, the world talks about what the impact of our food systems are on our environmental footprint.

“Now, this is a major new narrative. And to me, it’s very unusual and it’s very confusing as to why the same outlets that have touted this topic as being so paramount are not talking about these new findings whatsoever.

“So to me that’s problematic. And we have to think about why that is. Have we not explained it right? Is it too early for them to report about it? I don’t know, but this narrative is not going away.

“You will see it will gain momentum, and it will become the new reality.”

Why all greenhouse gases are not created equal

Dr Mitloehner said to date the global climate change debate has tended to focus only on how much greenhouse gases are emitted by different sources.

Most discussion fails to recognise that certain sectors of society, such as forestry and agriculture, also serve as a sink for greenhouse gases.

Climate debate focuses on the 560 tera-grams of methane emitted each year but tends to ignore the 550 tera-grams sequested by sinks like agriculture and forestry (right).

After the Kyoto protocol, the climate change debate centred on the 560 tera-grams of methane emitted into the atmosphere each year from all sources, including fossil fuel production and use, agriculture and waste, biomass burning, wetlands and other natural emissions.

“That is where most people stop the discussion, even though they shouldn’t,” he explained.

“Because in addition to emissions putting methane into the atmosphere, we also have sinks on the right side of this graph (above).

“And these sinks amount to a very respectable total number of 550 teragrams.

“So in other words, we have 560 teragrams of methane emitted, meaning put into the atmosphere, but then we have 550 teragrams of methane taken out of the atmosphere.

So in other words, the net emissions per year that we are dealing with is not 560, but it’s actually 10.

“Yet everybody talks about 560.”

In a biogenic carbon cycle, constant livestock herds or decreasing livestock herds over time did not add additional carbon to the atmosphere, he explained.

The carbon emitted by animals is recycled carbon. It came from atmospheric CO2, captured by plants, eaten by animals and then belched back out into the atmosphere, after a while becoming CO2 again.

Methane is a heat-trapping, potent greenhouse gas, and he stressed he was not suggesting that “it didn’t matter”.

But the key question for livestock is do ruminant herds add to additional methane, meaning additional carbon in the atmosphere which leads to additional warming?

The answer he said was clearly “no”.

Oxford University authors including Professor Myles Allen have shown that biogenic methane is not the same as fossil methane.

It is the same chemically, but the origin and fate “are totally, drastically different”.

“As long as we have constant herds or even decreasing herds, we are not adding additional methane, and hence not additional warming.

“This is a total change in the narrative around livestock. And I think this will be the narrative in the years to come.”

A chart documenting the size of the US cattle herd since 1867 shows it has decreased to around 90 million beef cattle and 9 million dairy cattle, down from peaks of 140 million beef cattle in the 1950s and 25 million dairy cattle in the 1970s.

The Australian cattle herd has similarly decreased from a peak of over 33 million cattle in 1976 to around 24 million today.

“We’re clearly see a decreasing number of livestock over the last few decades meaning with respect to livestock numbers, we have not cost an increasing amount of carbon in the atmosphere, but indeed we have decreased the amount of carbon we put into the atmosphere,” he said.

By contrast emissions from fossil fuel extractions were not part of a cycle, but “a one-way street”, because the amount of CO2 sent into the atmosphere in this process by far overpowered the potential sinks that could take up CO2, such as oceans, soils or plants.

“So here we have a one-way street. And this, ladies and gentlemen, is the main culprit of greenhouse gases in our atmosphere and the resulting warming.

“I have yet to see a climate scientist who would say that it’s the cows that are a primary culprit of warming. Most of them will agree that the primary culprit is the use of fossil fuels.”

“However, people critical of animal agriculture always point at cows, and cattle, and other livestock species. And they feel that this is a very powerful tool to ostracize animal agriculture as we know it.”

Not only were cattle not the primary culprit of global warming, they were also potentially part of the solution, as an explanation of stock gases versus flow gases demonstrated.

Long-lived climate pollutants such as Co2 were referred to as ‘stock’ gases because they last in the atmosphere for 1000 years. “Every time you put it into the atmosphere, you add to the existing stock of that gas,” he explained.

Methane (CH4) was a ‘flow’. Provided it was coming from a constant source, what was being put into the atmosphere was also being taken out.

“The only time that you really add new additional methane to the atmosphere with the livestock herd is throughout the first 10 years of its existence or if you increase your herd sizes.

“Only then do you actually add new additional methane and thus new additional warming.

“So please remember there are big differences between long-lived stock gases such as CO2 or nitrous oxide versus short-lived flow gases such as methane.”

He invited the audience to imagine a scenario where methane emissions from cattle were decreased by 35 percent.

If this could be achieved, it would have the effect of taking carbon out of the atmosphere and create a net cooling effect.

“If we find ways to reduce methane, then we counteract other sectors of societies that do contribute – and significantly so – to global warming, such as flying, driving, running air conditioners, and so on.

“So if we were to reduce methane, we could induce global cooling. And I think that our livestock sector has the potential to do it. And we are already seeing examples where that happens.”

He offered several examples of how the agricultural sector has already had success in reducing methane.

A few years ago the California legislature wrote a law called SB 1383 mandating a 40 percent reduction of methane to be achieved by the year 2030.

California’s farms and ranches have reduced greenhouse gases by 25pc since the laws were enacted.

This was achieved by using “a carrot rather than cane approach”, by rewarding farmers and ranchers who wanted to reduce emissions by giving them financial incentives to invest in anaerobic digesters or alternative manure management practices.

“I know if we can do it here, it can be done in other parts of the country and in other parts of the world.

“And if we indeed achieve such reductions of greenhouse gas, particularly of short-lived greenhouse gases such as methane, then that means that our livestock sector will be on a path for climate neutrality– on a path to climate neutrality. And that, to me, is a lifetime objective.”

Agriculture needs to work harder to tell its story

Dr Mitloehner said it was important the industry work harder to ensure the public understands the science around cattle production and greenhouse gas emissions.

“I feel that it is actually critical to get what we find in our research environment translated and communicated with the public sector.

“Because only if what we find makes its way to the light of the day, only then it matters”

It was also important that the public discussion used accurate and not misleading numbers around livestock emissions.

It is often stated that livestock emissions represent 14 percent to even as high as 50 percent of total emissions, but Dr Mitloehner said this did not reflect actual livestock emissions in developed countries such as the US were the number was closer to just 3 percent of all US emissions.

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Scientists understand cattle not climate villains, but media still missing message

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