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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Are Dairy Digesters the Renewable Energy Answer or a ‘False Solution’ to Climate Change?

Capturing the massive quantities of methane dairy farms emit could reduce overall carbon pollution. But critics say the effort is propping up Big Dairy.



 

logo for covering climate nowThis article is published in partnership with Covering Climate Now, a global journalism collaboration strengthening coverage of the climate story.

At first, California dairy farmer Felix Echeverria was skeptical about installing a dairy digester on his 12,000-cow operation. The process, which involved covering a pit of liquid manure and capturing the methane emissions it releases before “digesting” it anaerobically, is expensive and complex, and not something he was qualified to run. But he saw the benefits neighboring farmers in the Bakersfield area reaped from their digesters and decided to get ahead of a state law that would require him to reduce emissions by 2030.

“I realized I could stay ahead of the curve on greenhouse gas emissions,” Echeverria told Civil Eats. “To know we’ve been able to comply [with the law], that was the motive.”

The other deciding factor: Echeverria learned that he didn’t have to invest in or build the digester, as farmers in years past have. Instead, he partnered with a developer, California Bioenergy LLC (CalBio), that applied for public funding to help pay for the project and now operates the equipment. And in exchange for his manure biogas, Echeverria earns a percentage of sales from the electricity generated by the digester.

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“There’s absolutely no drawbacks,” Echeverria said of the digester, which has operated on the farm since 2018.

Agriculture accounts for nearly a quarter of global greenhouse gas emissions, and as its role in changing the climate has become increasingly clear, farmers like Echeverria are being asked to do their part. In recent years, much of the attention—and the bulk of public dollars—has focused on anaerobic digesters, which help meat and dairy production facilities convert animal waste into energy that fuels vehicles and power grids.

Farmers, researchers, and policymakers across the U.S. see methane digestion as cost-efficient, effective, and revenue-generating for farmers. Proponents also see biogas and its cleaned-up version, biomethane (also known as renewable natural gas, or RNG) as a renewable source of energy that has a huge potential to replace more harmful legacy fuels.

Over the past decade, more than 250 digester projects have been built across the country, most of them on dairy farms. California alone has funded more than 100 digester projects, spending nearly $200 million of its ambitious California Climate Investments dollars on them. The state is poised to spend an additional $20-$25 million this year, though it’s unclear how the COVID-19 pandemic will impact the funding process going forward.

“The primary beneficiaries of these projects are the citizens of California. By reducing greenhouse gases, we are contributing to reducing global warming,” said Joyce Mansfield with the California Department of Food and Agriculture (CDFA), which runs a grant program for dairy digesters.

But digesters do have some drawbacks. They’re complex, expensive projects that farmers can’t afford on their own; they cost $3-5 million dollars each and typically require public subsidies to build—in the form of federal loans, state grants, tax credits, rebate programs, and myriad other incentives.

In the past, environmental advocates have supported digesters, but many have begun to see the technology in a new light. They say the emission reductions are not worth the massive public funding given that most manure-powered biogas comes from large-scale industrial dairy facilities known for their significant environmental impacts. (Straus Family Creamery in Northern California is one of a few exceptions.) As such, advocates say public financing of digesters amounts to supporting and helping to perpetuate large-scale factory farming—and in some cases, causing farms to grow in size—under the guise of mitigating climate change.

“Digesters are definitely reducing methane and generating fuel [and] electricity. It all sounds very good, but it’s not a clean fuel,” said Rebecca Spector, the West Coast director for the Center for Food Safety. “These enormous dairies are polluting the air and the water … and the state is promoting a false solution while propping them up.”

Ultimately, Spector said, portraying digesters as a panacea to dairies’ environmental woes is thwarting the move to a farming system that supports smaller-scale producers, reduced herd sizes, and cows on pastures. “We want dairies to move to more sustainable solutions and we support the state incentivizing that,” she said.

Pressure to Reduce Emissions

Large industrial dairies, also known as concentrated animal feeding operations, or CAFOs, clean manure out of their barns with water and store the liquid waste in large lagoons. As naturally occurring bacteria break down the manure, they release large quantities of methane, a greenhouse gas with a 25 times greater impact on global warming than carbon dioxide. In fact, more than half of California’s methane emissions come from dairies.

Manure management accounts for about 7 percent of agriculture emissions and in recent years, dairies across the U.S. have faced increased pressure to reduce that number. In California, the country’s largest dairy state, producers are required by 2030 to decrease their methane emissions by 40 percent from 2013 levels. And while much of the methane comes from cows belching, dairy manure lagoons account for approximately 25 percent of the state’s overall methane emissions.

Reducing those emissions is no small feat. In 2017, California housed 1.7 million cows—the vast majority of them residing in the Central Valley on approximately 1,300 dairies. According to the U.S. Environmental Protection Agency (EPA), an average dairy cow produces approximately 120 pounds of manure every day.

The digesters capture methane, convert the biogas to biomethane, and inject it into utility pipelines as renewable compressed natural gas (R-CNG) to power trucks, buses, and cars. In some cases, digesters also generate renewable electricity that’s used by the dairy, with the remainder sent into the grid. Dairy methane can also be turned into renewable electricity without combustion to power electric vehicles.

Because of the expense and scale of the projects, digesters are geared toward large dairies.

In the past, dairy producers built and operated their own digesters. But in recent years, as the projects have become more complex and their price tags have ballooned, big developers have largely taken over their funding, building, operating, and maintenance. Most of the digesters are now part of clusters, with the biogas sent to a centralized cleaning hub.

Because of the expense and scale of the projects, digesters are mainly geared toward large dairies—2,500 cows with support stock could support a standalone digester, according to digester developers. If a dairy is near a cluster project, it might work for it to be somewhat smaller.

While digesters may be expensive, data collected at the state level shows digester projects are cost-effective when it comes to reducing greenhouse gas emissions. In fact, the digester program is the second most cost-effective of the state’s 68 climate programs.

“Our projects are providing high value for the state in terms of return on their investment,” CalBio’s President Neil Black wrote in an email. “We are destroying methane, which has greater short-term warming impacts in initial years… [so] the climate benefits will be seen much sooner than projects that reduce carbon dioxide.”

Indeed, the greenhouse gas reductions can be substantial. Echeverria’s dairy digester was expected to cut its manure methane emissions by approximately 75 percent. It will also reduce energy costs and its use of fossil electricity from the grid. The digester delivers approximately 8 million kilowatt-hours of renewable electricity annually to state utility, Pacific Gas & Electric (PG&E). And the dairy is part of the Kern County Dairy Biogas cluster, a group of 16 dairies with approximately 60,000 milk cows that collectively produce approximately 6 million diesel gallon equivalents per year.

For large dairies, digesters can be a godsend: they cut the cost of complying with environmental rules, and offer a new source of revenue to supplement volatile milk prices. Farmers can also use electricity-engine waste heat to refrigerate their milk, resulting in further savings.

Digesters also provide benefits beyond emission reductions, Echeverria said. “We don’t have as much solids to deal with in the waste stream because a lot more material gets digested and turned into gas. We can move it around easier, our lagoons stay cleaner, and we get a better fertilizer source,” he said, referring to the fact that nutrients are broken down more thoroughly in the digester and are more available to the plants when the manure is spread on fields. And because digester projects are required to double-line the lagoons, he says nitrates don’t leach into groundwater.

Digesters also reduce emissions of hydrogen sulfide and other gases, said Black, CalBio’s president, improving air quality and reducing odors. The company is working to help convert truck fleets from diesel to natural gas, he said, which will significantly reduce nitrogen oxides, a major component of smog, in the highly polluted Central Valley where residents live with some of the worst fine particle pollution in the nation.

But Spector with the Center for Food Safety contends that while digesters do provide some benefits, they don’t solve the issue of nitrates contaminating groundwater—a major issue in the Central Valley, where low-income residents are often forced to rely on bottled water. That’s because nitrates often leach from manure applied as fertilizer into groundwater. Spector says that when digesters burn biogas they also produce air pollution. In addition, the digesters don’t address the climate impacts of enteric emissions (from cows releasing gas) which account for about half of the methane emissions from dairies.

Subsidies for Developers, Revenue to Industrial Dairies

Critics also decry the fact that much of the public funding for dairy digesters has gone into the hands of just a few developers.

In California, the CDFA has created a research and development program that is funded with the state’s cap and trade dollars. From 2015 to 2019, the program has awarded over $180 million to 108 projects, the agency told Civil Eats. And yet the vast majority of that money has gone to just two developers (only 12 developers have ever applied, the agency said).

CalBio has receive the largest amount: $99 million to date. And Maas Energy Works has been awarded $82.5 million. The CDFA grants require a 50 percent financial match, though those funds can also come from other public sources. Both companies also say they have received other public funding for their projects. Additional capital for the projects comes from investors and lenders.

CalBio currently operates five projects in California and is developing, according to its officials, more than 60 additional digesters in seven clusters of existing dairies that will produce renewable compressed natural gas for use in vehicle fleets. Maas Energy Works has a total of 27 digester projects, including 22 in California, three in Washington state, and two in Oregon.

“California has required the dairy industry to reduce their methane emissions by 40 percent. The best way to achieve that reduction is with dairy digesters,” Maas Energy Works spokesman Doug Bryant told Civil Eats via email.

The digester projects are a financial boon to both the developers and farmers. While in previous years, their value was based around renewable electricity generation and the sale of carbon credits, it now comes from the production of low carbon fuel, through the sale of natural gas, as well as the generation and sale of “credits” that can be sold to polluting companies and other organizations that use them to comply with state and federal requirements or voluntary emissions goals.

Precisely who benefits from these income streams varies from project to project. But with the new generation of digesters, it is often the developers who bring in the capital and who then own the digesters while the dairy producers rent their lagoon and provide the manure in return for a cut of the power sold. “Our company helps bring in the capital from lenders and investors. The dairies… receive the payment for contributing their manure, and the better the project performs, the more they will make,” said CalBio’s Black.

He added that dairies have an opportunity to invest in their projects, but that is optional. In Maas Energy Works projects, on the other hand, over half of the projects are 100 percent owned by the dairy farmer and the developer simply operates the digester for a fee, the company told Civil Eats.

Fight Over Renewable Gas

In the coming years, digester developers and dairy farmers may tap into an even bigger source of income as the gas industry looks to replace some of the “fossil-based” natural gas it currently sells. Natural gas companies such as SoCalGas and PG&E have heavily promoted biogas as a cost-effective, reliable “renewable natural gas.” The private utilities say that mixing RNG with regular gas in their pipelines will reduce its carbon intensity. And it appears the gas industry may get its way, at least in the short term.

While in the past, digester projects generated electricity for export to the grid, the current focus is on using the dairy biomethane—in the form of CRNG—as an alternative vehicle fuel and energy source. Out of 108 projects funded by the CDFA since 2015, 102 produce or will produce CRNG. And in recent years, these are built in a cluster of digesters that pipe gas to a centralized hub.

Two years ago, a new California law essentially mandated that a certain amount of biogas from manure and other renewable sources be included in utilities’ energy mix and for it to be injected into the gas pipeline system. The California Public Utilities Commission is currently in the process of creating a procurement standard to make that possible.

Legislators recently extended the ability to tap into $40 million in subsidies through a program that connects manure digesters to utility pipelines. And the SoCalGas settlement for the Aliso Canyon gas leak is also channeling $26.5 million toward the construction of dairy digester projects.

While some have praised this move, critics say it has created a whole set of ethical issues. Jim Walsh, a senior energy policy analyst with Food & Water Watch, says that using California Climate Investment funds to produce renewable gas from biomethane that utilities want in their portfolio supports not only factory farming but also the legacy fossil fuel industry—and could ultimately allow it to continue its polluting ways.

“These cap and trade funds are huge subsidies that utilities and other large polluters pay for to avoid their own emission reductions…. It allows them to greenwash themselves while proceeding with their practices,” Walsh said. “This is really just a shallow attempt to extend the life of their industry in the face of a growing backlash against fossil fuel development.”

Using biogas from manure as part of utilities renewables portfolio isn’t cost effective either, Walsh added, and will significantly increase rates for consumers. Methane-derived RNG can also leak through pipelines when transported, just like natural gas. And the bet on biogas from dairies is happening just as cities around the country are focusing more on electricity and passing laws to stop the building of new gas infrastructure.

In California, state officials have also pushed electricity as a strategy for cutting emissions from homes and workplaces. Meanwhile, utilities like SoCalGas counter that using biogas as part of their energy mix can reduce greenhouse gas emissions faster and cheaper than electrifying buildings.

Ultimately, what could make utilities’ move to biogas problematic is simply a problem of supply. Studies show there likely won’t be enough RNG/biomethane to meet the state’s climate goals.

Alternatives Underfunded, Lag Behind

Dairy digesters aren’t the only way to manage manure’s methane impact, but environmentalists say that other, more cost effective and sustainable methods tend to be much harder to get funded.

The CDFA runs a second methane reduction grants program called the Alternative Manure Management Program (AMMP). Those include projects focus on different ways to handle manure, such as composting and conversion to something called dry scrape collection, as well as enhanced pasture-based management practices (though few producers have applied to move their cows to pasture).

The program’s funding makes up only 20-30 percent of the total available for methane reduction programs, records show. More producers apply for the AMMP funding than for digester dollars, but in 2019 about half were rejected due to lack of funding.

The CDFA told Civil Eats that the dairy digester program has greater reductions of greenhouse gases than the alternative program. But Jeanne Merrill, policy director of California Climate and Agriculture Network (CalCAN), said the agency’s comparison is flawed. The CDFA calculates emission reduction impacts from AMMP projects on a 5-year project basis, she said, while those from the digester projects are calculated on a 10-year basis. “That’s comparing apples to oranges,” Merrill said.

CDFA officials said they use those time spans because they represent the expected duration of the projects. But Merrill said when greenhouse gas reductions are compared across both programs using similar timeframes, the AMMP projects fare quite well and sometimes do a better job with emission reductions per dollar.

AMMP projects are also faster to implement. Of the 108 digester projects awarded grants since 2015, only 13 are now complete and operational. The remaining 95 are at different stages of implementation.

Alternative methane reduction projects can also help protect water and air quality, Merrill added. Because they’re less expensive, they’re accessible to smaller farms and have greater geographic impact. And while digester projects are only guaranteed for 10 years (although Maas Energy Works told Civil Eats its digesters are expected to survive for at least 20), alternative projects are not subject to changes in complex technologies so are easier to maintain long-term.

“The trouble with digesters is that they only work for a quarter of the state’s dairies,” Merrill said. “Small and middle-sized dairies don’t have enough manure or capital to justify building digesters.”

Given the benefits, Merrill added, the CDFA should allocate half the available funding to non-digester programs.

Coronavirus May Stem the Tide of Funding

As the COVID-19 pandemic rages through California and the rest of the country, it’s still unclear how it might impact dairy digester projects. The pandemic has battered many smaller dairy farmers, with demand for dairy dropping and milk prices at historic lows. But both California Bioenergy and Maas Energy Works told Civil Eats that beyond minor delays and a slow-down in financing, the virus has had a limited impact on their operations so far.

In the near term, the impact may be financial. Before the pandemic, California’s governor Gavin Newsom proposed a budget that included a new ambitious Climate Catalyst Fund of $1 billion over the next four years. Companies—including farms and digester developers—could apply to get low-interest loans to reduce their climate impacts. That budget proposal, Newsom now says, “is no longer operable” and will have to be revised.

But given the fact that CDFA set its budget for 2020 loans last year, even the pandemic isn’t likely to stop the state’s fledgeling dairy digester industry from progressing—at least for the foreseeable future.

 

Top photo: The Riverview Dairy Digester in Pixley, California. It receives manure from roughly 3,000 cows, plus replacement stock. (Photo courtesy of Maas Energy Works)

Methane’s Rising: What Can We Do to Bring It Down?

ATMOSPHERIC SCIENCES  Editors’ Vox


Reducing methane emissions is critical for addressing climate warming, but which are the easiest and most cost-effective ways to do this?

By 

Methane emissions have increased dramatically over the past decade and a half, significantly contributing to climate warming. A recent article in Reviews of Geophysics examines how to measure methane emissions accurately from different sources, and explores various mitigation and emission reduction strategies. Here, one of the authors explains the causes of increased emissions, the imperative to address this problem, and what we might be able to do about it.

What are the main sources and sinks of atmospheric methane?

Methane comes from many sources. Roughly two-fifths of emissions are natural, such as wetlands, and three-fifths are human-caused, such as leaks from fossil fuel industries, ruminant farm animals, landfills, rice growing, and biomass burning.

Landfill site in Kuwait
Landfill site in Kuwait. Credit: D. Lowry, from Nisbet et al. [2020], Figure 3

The main sink for methane is destruction by hydroxyl (OH) in the sunlit air, especially in the tropics in the moist air a few kilometers above the surface. Other smaller sinks are chlorine in the air, and destruction by bacteria in the soil.Why has there been a sharp rise in atmospheric methane over the past few decades?

Methane emissions rose quickly in the 1980s as the natural gas industry was rapidly expanding, especially in the former Soviet Union. Then the growth rate slowed and the methane budget (the balance between emissions and their destruction) seemed to have reached equilibrium in the early years of this century. However, in 2007, unexpectedly, the amount of methane in the air started growing again, with very strong growth since 2014, much of it in tropical regions [Nisbet et al., 2019].Simultaneously, there was a marked change in the isotopic composition of atmospheric methane. For two centuries, the proportion of Carbon-13 in the methane in the air had been growing, reflecting the input from fossil fuels and fires, which is relatively rich in C-13, but from 2007, the proportion of C-12 methane has risen [Nisbet et al., 2016].

There is no clear agreement why this rise in methane began again in 2007, nor why it accelerated from 2014, nor why the carbon isotopes are shifting. One hypothesis is that biological sources of methane have increased; for example, population growth has increased farming in the tropics, and climate warming has made tropical wetlands both warmer and wetter. Another possible hypothesis is that the main sink has declined; if true, this would be profoundly worrying as OH is the ‘policeman of the air’ cleaning up so many polluting chemical species. A third hypothesis is more complex, speculating that fires (which give off methane rich in C-13) have declined while other sources have risen. Of course, these hypotheses are non-exclusive and all these processes could be happening at the same time.

Why is a focus on reducing methane emissions critical for addressing climate warming?

Methane is an extremely important greenhouse gas. In its own right, it is the second-most important human-caused climate warmer after carbon dioxide (CO2), but it also has a lot of spin-off effects in the atmosphere that also cause warming.In the 5th Assessment Report from the Intergovernmental Panel on Climate Change (IPCC) in 2013, warming from methane was assessed at about 0.5 watts per square meter (Wm-2) (the measure of solar irradiance) compared to the year 1750. That’s large, and when all its spin off impacts are added, the warming impact of methane was around 1 Wm-2 (IPCC 2013 report Fig. 8.17), which is significant when compared to about 1.7 Wm-2 warming from CO2. Sadly, both numbers of course have now much increased.

Methane’s atmospheric lifetime (the amount in the air divided by the annual destruction) is less than a decade. So, if methane emissions are quickly reduced, we will see a resulting reduction in climate warming from methane within the next few years. Over the longer-term CO2 is the key warming gas but reducing that will take much longer, so cutting methane is an obvious first step while we try to redesign the world’s economy to cut CO2. It’s rather like a dentist giving a quick acting pain reliever while making plans for a root canal procedure.What might be the some of the easiest or most cost-effective ways to cut methane emissions from different sources?

Simple box model to show the potential impact of mitigation on methane emissions
Simple box model to show the potential impact of mitigation. The purple line approximates emission levels that would be compliant with the Paris Agreement. The blue line represents no change in emissions after 2020. The other lines show a 10% (orange line), 20% (green line) and 30% (red line) cut in emissions spread linearly over the period 2020–2055 followed by stable emissions. Credit: Paul Griffiths, in Nisbet et al. [2020], Figure 22 left panel

We need to identify the major human-caused sources that we can realistically change quickly.Some relating to the fossil fuel industry are easily identified and already subject to regulatory control in most producing nations, so it should not be difficult to monitor and achieve better behavior. For example, gas industry leaks represent lost profit, while deliberate methane venting in the oil industry is simply lazy design. Meanwhile, the coal industry is rapidly becoming uncompetitive with renewable electricity.

Tropical fires are a particular problem and cause terrible pollution. Many fires are either unnecessary (such as crop waste fires and stubble burning) or very damaging (such as human-lit savanna grassfires and forest fires) so there is a very strong argument for using both financial incentives and legislation to halt fires across the tropics, although in some places there are strong vested interests.

Landfills are another significant source. Although these are highly regulated in Europe and parts of the Americas, in megacities in the tropics there are many immense landfills, often unregulated and often on fire. Just putting a half-meter of soil on top would greatly cut emissions.

And what are some of the most challenging types methane sources to address?

Changing food habits is perhaps the biggest challenge. Much methane is breathed out from ruminant animals such as cows, water buffalo, sheep, and goats. Across much of tropical Africa and India, cows tend to live in the open and their manure is rapidly oxidized so it is not an especially large methane source. But in Europe, China and the United States, cattle are often housed in barns with large anaerobic methane-producing manure facilities, that do make methane. These manure lagoon emissions should be tackled.

We could, of course, all give up food from ruminants and methane emissions would drop, but it would be countered by an increasing demand for crops. More intensive arable farming, especially in the tropics, would be needed, and likely achieved by plowing up forest and savannas, which would increase CO2 emissions, and also require increasing the use of nitrogen fertilizers.

Reducing meat and dairy consumption to only ‘organic’ grass-reared animals seems like a sensible first step for people in wealthier nations. But this needs to be seen in the context of broader issues in less developed nations. Population growth needs to be slowed if agricultural emissions are to be reduced: better schools, especially for girls, improved healthcare, and better pensions would reduce population growth and thus the burden on human food production. A focus on societal issues would ultimately address climate problems too.

Can we be optimistic that efforts to reduce methane emissions will help to meet the targets of the UNFCCC Paris Agreement?

If I’d been asked this question three months ago, I would have said “no”. Methane is rising much faster than anticipated in the scenarios that underlay the Paris Agreement. As I write we are several months in to the global COVID-19 epidemic and it is almost as if nature itself has so tragically hit the pause button. I am one of many scientists trying to measure the impact of the lockdown on CO2 and methane emissions. As we try to rebuild and find our way through the post-epidemic recovery, there will be great changes, and perhaps in many countries a pause for thought, and a chance to choose a new way forward.

—Euan Nisbet (E.Nisbet@rhul.ac.uk), Department of Earth Sciences, Royal Holloway, University of London, UK

Citation: Nisbet, E. (2020), Methane’s rising: What can we do to bring it down? , Eos, 101, https://doi.org/10.1029/2020EO143615. Published on 04 May 2020.
Text © 2020. The authors. CC BY-NC-ND 3.0

Study: Climate impact of butter 3.5 times greater than plant-based spreads


https://www.businessgreen.com/news/4012376/study-climate-impact-butter-times-plant-spreads

The climate impact of butter is higher in large part due cow's methane-heavy farts
The climate impact of butter is higher in large part due cow’s methane-heavy farts

Cow’s methane-heavy burps and farts blamed for CO2 associated with butter in study commissioned by margarine maker Upfield

The climate impact of consumer diets has yet again fallen under the spotlight, after research this week concluded butter is 3.5 times more harmful to the environment on average than margarine and plant-based spreads, due in large part to cows’ methane emissions.

The study was commissioned by global margarine maker Upfield – responsible for plant-based brands including Flora, Rama and Blue Band – in another sign of how firms are seeking to promote the climate credentials of their products to increasingly eco-conscious consumers.

It asked scientists to carry out a large-scale life cycle assessment looking at the production, transport, sale, and use of 212 plant-based spreads and margarines sold across 21 European and North American markets, and then compare their greenhouse gas emissions to the impact of 21 dairy butters.

The results found the average CO2 impact for every kilogram of plant-based spread and margarine produced was around 3.3kg, compared to 12.1kg of CO2 equivalent for dairy-based products, making emissions from butter around 3.5 times higher.

The bulk of emissions associated with butter occur during milk production, according to the study, which found enteric emissions from cows – aka methane from burping and farting – made up 39 per cent of greenhouse gases from dairy-based spreads.

It means that just one 250g of butter results in the equivalent of 1kg of cow emissions, the study estimated, with methane a particularly potent greenhouse gas which is around 80 times more powerful than CO2 at trapping heat, and responsible for around a quarter of global warming.

Every one of the 212 plant-based spreads analysed fared much better in the study in terms of carbon impact, with associated emissions ranging from less than 1kg to almost 7kg, whereas butter products generated between over 8kg to nearly 17kg of CO2 for every kilogram produced.

Beyond emissions too, the life cycle assessment – the largest of its type to date, according to Upfield – concluded that margarines and plant-based spreads consistently had lower impacts than butter in terms of climate, water and land.

Cattle feed production including cow burps, farts, and manure management “contributed significantly to climate change impacts, with a higher impact than most other factors”, the study found. Some farming groups have argued that new diet supplements and other technologies can serve to curb methane emissions from cattle, but the industry is still regarded as a large and growing source of emissions.

Sally Smith, head of sustainability at Upfield, said the study highlighted the need for a “fundamental transformation of our food system” in order to tackle climate change, arguing that people in western countries needed to cut down on their meat and dairy intake.

She also argued it was important for firms to help consumers to understand the impact of their food choices on the planet. “It is our responsibility as a forward-thinking company to understand and act to address the impact of our plant-based products on the environment,” said Smith. “A shift to regenerative agricultural practices will be key for both arable and dairy farmers. Robust lifecycle assessments help ensure that our approach is data driven and grounded on the latest scientific evidence.”

NASA Flights Detect Millions of Arctic Methane Hotspots

Thermokarst lake in Alaska
The image shows a thermokarst lake in Alaska. Thermokarst lakes form in the Arctic when permafrost thaws. Credit: NASA/JPL-Caltech
› Larger view

Knowing where emissions are happening and what’s causing them brings us a step closer to being able to forecast the region’s impact on global climate.


The Arctic is one of the fastest warming places on the planet. As temperatures rise, the perpetually frozen layer of soil, called permafrost, begins to thaw, releasing methane and other greenhouse gases into the atmosphere. These methane emissions can accelerate future warming – but to understand to what extent, we need to know how much methane may be emitted, when and what environmental factors may influence its release.

That’s a tricky feat. The Arctic spans thousands of miles, many of them inaccessible to humans. This inaccessibility has limited most ground-based observations to places with existing infrastructure – a mere fraction of the vast and varied Arctic terrain. Moreover, satellite observations are not detailed enough for scientists to identify key patterns and smaller-scale environmental influences on methane concentrations.

In a new study, scientists with NASA’s Arctic Boreal Vulnerability Experiment (ABoVE), found a way to bridge that gap. In 2017, they used planes equipped with the Airborne Visible Infrared Imaging Spectrometer – Next Generation (AVIRIS – NG), a highly specialized instrument, to fly over some 20,000 square miles (30,000 square kilometers) of the Arctic landscape in the hope of detecting methane hotspots. The instrument did not disappoint.

“We consider hotspots to be areas showing an excess of 3,000 parts per million of methane between the airborne sensor and the ground,” said lead author Clayton Elder of NASA’s Jet Propulsion Laboratory in Pasadena, California. “And we detected 2 million of these hotspots over the land that we covered.”

The paper, titled “Airborne Mapping Reveals Emergent Power Law of Arctic Methane Emissions,” was published Feb. 10 in Geophysical Research Letters.

Within the dataset, the team also discovered a pattern: On average, the methane hotspots were mostly concentrated within about 44 yards (40 meters) of standing bodies of water, like lakes and streams. After the 44-yard mark, the presence of hotspots gradually became sparser, and at about 330 yards (300 meters) from the water source, they dropped off almost completely.

The scientists working on this study don’t have a complete answer as to why 44 yards is the “magic number” for the whole survey region yet, but additional studies they’ve conducted on the ground provide some insight.

“After two years of ground field studies that began in 2018 at an Alaskan lake site with a methane hotspot, we found abrupt thawing of the permafrost right underneath the hotspot,” said Elder. “It’s that additional contribution of permafrost carbon – carbon that’s been frozen for thousands of years – that’s essentially contributing food for the microbes to chew up and turn into methane as the permafrost continues to thaw.”

Scientists are just scratching the surface of what is possible with the new data, but their first observations are valuable. Being able to identify the likely causes of the distribution of methane hotspots, for example, will help them to more accurately calculate this greenhouse gas’s emissions across areas where we don’t have observations. This new knowledge will improve how Arctic land models represent methane dynamics and therefore our ability to forecast the region’s impact on global climate and global climate change impacts on the Arctic.

Elder says the study is also a technological breakthrough.

“AVIRIS-NG has been used in previous methane surveys, but those surveys focused on human-caused emissions in populated areas and areas with major infrastructure known to produce emissions,” he said. “Our study marks the first time the instrument has been used to find hotspots where the locations of possible permafrost-related emissions are far less understood.”

More information on ABoVE can be found here:

https://above.nasa.gov/

Are we measuring ruminant methane emissions correctly?

17 January 2020

Researchers at Oxford University have developed GWP*, a new climate metric that accurately measures the impact of methane emissions on global warming – recontextualising the debate surrounding ruminant methane emissions and climate change.

ffinlo Costain, host of FAI Farm’s Farm Gate podcast interviewed Myles Allen and John Lynch from Oxford University to explore their new method of measuring the impacts of methane on climate change. GWP* is a new metric for global warming potential that measures the change in emission rates for methane instead of measuring emissions by volume. According to their research, GWP* gives a more accurate picture of the influence greenhouse gases have on the world’s climate than existing measures, which assign gases a nominal CO2 equivalent number.

Current climate measures, like GWP100, categorise ruminant-emitted methane and agricultural activities among the greatest contributors to climate change. GWP100 reaches this conclusion by comparing the total amount of emissions and extrapolating the potential impacts on the global climate. According to Roland Bonney, co-founder of FAI Farms and Benchmark Holdings plc, many farmers and farm organisations feel unfairly demonised by these conclusions and public reaction to them. Allen and Lynch echo this view and assert that the GWP100 metric doesn’t capture the full relationship between emissions and climate change.

Bonney asserts that raising ruminants sustainably can be part of the solution to climate change. Raising cattle and sheep in a mixed rotation system, ensuring they are grass-fed and that they have access to natural pastureland can reduce greenhouse gas emissions significantly. In his view, how we farm has a greater impact on global climate than what we choose to eat.

The differences between methane and carbon dioxide

Though both methane and CO2 contribute to climate change, they impact global temperatures differently. Humans emit more carbon dioxide than any other greenhouse gas and it remains the largest contributor to climate change. Though some CO2 can be absorbed by the ocean or be fixed in plant biomass, the bulk of human emissions go into the atmosphere. According to Allen, the CO2 left in the atmosphere causes a persistent warming effect over thousands of years, making its impact more cumulative than other gasses. Unless humans ramp up efforts to remove carbon, it will remain in the environment.

In contrast, methane is emitted in smaller quantities. The gas has a stronger warming effect than CO2, but it breaks down quickly. This means that after a few decades, the methane will be out of the atmosphere and any warming affects will cease.

When describing the different impacts of the gases, Lynch compared the impacts of methane emissions to drinking excessively and getting a hangover – the immediate effects will set you back, but as long as you don’t drink to excess again, the pain and nausea will dissipate. Carbon dioxide, on the other hand, is more akin to lead poisoning – exposure will cause immediate negative effects, and sustained exposure will cause significant damage in the future.

Metaphors aside, comparing one tonne of emitted CO2 to one tonne of emitted methane (CH4) doesn’t give researchers an accurate picture of the gases’ warming potential. Allen’s research indicates that for methane to have the same warming effect as CO2, humans would need to increase methane emissions by multiple tonnes per year and maintain that emissions level indefinitely. In his view, it’s more appropriate to compare the emission rates of methane with a single tonne of emitted carbon dioxide – the central aim of the new GWP* measure. The new metric will also give more accurate climate forecasting than the current GWP100 standard.

GWP* appears to capture these subtleties more effectively than GWP100. Researchers at the SRUC found that measuring the warming impact of farms with a traditional carbon calculator overestimated the impact of farm emissions on climate. When they used GWP* to analyse the same farm data however, methane emissions fell by 75 percent, halving the total climate impact of agricultural emissions.

Ruminant methane and GWP*

In Allen’s analysis, methane’s contribution to climate change is historic – we are feeling the effects of methane pulses from 50 years ago when the global ruminant herd increased. Ruminants contribute to global methane emissions as the herd expands. A new source of methane will have a huge effect, but a sustained source won’t be as impactful. If the herd remains stable or declines (which is happening currently), the methane they produce won’t add to the warming that’s already occurred. Allen argues that the methane produced by the world’s ruminants is keeping global temperatures at stasis – it isn’t contributing to warming or cooling either way.

GWP* allows researchers to differentiate between new sources of methane and existing ones, meaning that fluctuations in the global ruminant herd can be accurately accounted for. According to Lynch, analysing discrete methane sources makes GWP* more accurate and prevents overestimates of the gas’s climate effects.

In Allen’s view, removing all ruminants in order to tackle methane emissions wouldn’t provide a huge climate benefit. Culling ruminants would only give the climate a temporary pulse of cooling – a temporary reduction of 0.1 degrees at the absolute maximum. That’s the equivalent of a few years’ worth of warming from CO2 emissions. Instead of focusing solely on ruminant emissions, activists should also account for methane leakages in Britain’s natural gas infrastructure. Both Lynch and Allen agreed that eliminating CO2 emissions would do more to counteract climate change than simply reducing methane produced by ruminants.

Refocusing on carbon

Allen told Costain that though reducing methane would help the climate, tackling carbon emissions from the fossil fuel industry is more pressing. The emissions from this sector are “additional” to the world’s existing carbon cycle and cause present and future warming events. Unless the UK and other countries enact zero net carbon emissions policies, global climate change will continue. Lynch echoed these sentiments, saying that carbon emissions needed to be removed or offset to stabilise global temperatures.

Listen to the Farm Gate podcast with ffinlo Costain here.