Efficient meat and dairy farming needed to curb methane emissions, study finds

Authored by news.agu.org and submitted by rustoo

Liza Lester, +1 (202) 777-7494, [email protected] (UTC-4 hours)

Jiangfeng Chang, Zhejiang University, [email protected], (UTC+8 hours)

WASHINGTON— Adopting a plant-based diet can help shrink a person’s carbon footprint. But a new study finds that improving the efficiency of livestock production will be an even more effective strategy for reducing global methane emissions.

The new study looked at the intensity of methane emissions from livestock production around the world — in other words, how much methane is released for each kilogram of animal protein produced — and made projections for future emissions. The authors found in the past two decades, advances in farming have made it possible to produce meat, eggs and milk with an increasingly smaller methane footprint.

Some countries, however, have not had access to the technology enabling these advances. The authors show that improving the efficiency of livestock farming, especially in some emerging economies, will be necessary to make meaningful cuts to methane emissions.

These efforts are predicted to have a greater impact than simply encouraging people to eat less meat, according to the new study, published today in AGU Advances, which publishes high-impact, open-access research and commentary across the Earth and space sciences.

The paper’s results can help inform future climate policy, and the methods developed in the study will allow countries to make up-to-date estimations of their methane emissions from livestock.

The authors emphasize that these improvements should not come at the expense of the environment, as can occur in factory farming.

“We do not endorse the industrial livestock system for methane mitigation, because it causes many other environmental problems like pollution, failed manure management and land-use changes for grain and high-quality fodder,” said Jinfeng Chang, an environmental scientist at Zhejiang University and first author of the new study. “There are many other more sustainable ways to improve efficiency.”

Globally, raising animals for milk, meat and eggs accounts for one-third of human methane emissions. Dairy and beef cows are the top contributors, due in part to their large numbers. Also, cows are ruminant animals, like buffalo, sheep and goats, and the microbes in their guts produce methane as a by-product of breaking down their food. According to the Food and Agriculture Organization of the United Nations (FAO), methane emissions from livestock rose more than 50% between 1961 and 2018, and are expected to continue to rise as demand for animal products increases, especially in countries with growing populations and income.

In the study, the authors created new estimates of global methane production from livestock using the most recent methods proposed by the Intergovernmental Panel on Climate Change (IPCC). Next, they calculated the production efficiency for each country, using livestock production data from the FAO. The analysis looked at all types of animal products, including milk and meat from cattle, buffaloes, goats and sheep, pork products, poultry and eggs.

From 2000-2018, even as total emissions rose, the intensity of emissions from most types of livestock fell globally as production became more efficient. This drop resulted from advanced breeding practices and improvements in nutrition, which created animals that yielded more milk and meat.

When the authors looked at methane emissions under future scenarios, they saw that, while eating less meat will help, continuing these gains in production efficiency has even more potential for cutting methane, especially in countries with low efficiency and high future production. They calculate that under a “Business-As-Usual” socioeconomic scenario, agricultural improvements in the top 10 countries with the greatest potential to reduce methane could account for 60-65% of the decrease in global methane emissions by 2050 from increasing efficiency.

“They made it absolutely clear that improving production efficiency has much greater mitigating effect than demand-side efforts, particularly in low-income countries,” said Ermias Kebreab, an animal scientist at the University of California, Davis, who was not involved in the research.

Kebreab agrees that increasing efficiency without causing environmental damage is possible and that some regions could improve their efficiency by up to 20%. With cattle, for example, cows adapted to the local environment can be bred with high-yield breeds to increase meat and milk production. Software in the local language can then formulate a balanced diet to support the crossbred cattle using feed available in the region. “It’s just it’s a matter of resource allocation.”

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AGU Advance is an open access journal. Download a PDF copy of the paper here. Neither the paper nor this press release is under embargo.

“The key role of production efficiency changes in livestock methane emission mitigation”

-GabeHitch- on May 28th, 2021 at 18:19 UTC »

When reading the study itself, we see there's a discrepancy between the article and the study. They've reworded the findings to make a different argument.

Article: "Adopting a plant-based diet can help shrink a person’s carbon footprint. But a new study finds that improving the efficiency of livestock production will be an even more effective strategy for reducing global methane emissions."

Study: "Our results highlight the fact that (a) efforts on the demand-side to promote balanced, healthy and environmentally sustainable diets in most counties, as assumed in the TS scenario (FAO, 2018), will not be sufficient for livestock methane emission mitigation without parallel efforts to improve production efficiency and decrease the emission intensity per unit protein produced; and (b) efforts to decrease emission intensity should be prioritized in a few developing countries with the largest mitigation potential."

So they're saying that based on their findings, both are needed, but they think (b) should be prioritized in some developing countries due to their conditions. They don't seem to factor in methane from the animal feed production, but only count methane from the animals themselves. Probably because they mostly compare grain-fed animals with grass-fed ones rather than comparing meat-fed humans with plant-fed ones.

Based on the article's argument (not the study), which seems to be claiming plant-based diets are less effective than improving efficiency, there's a problem in not counting animal feed into the equation. In a 100% plant-based diet, the only pollution comes from the production of the plants. With meat, however, the pollution comes from both the production of the plants as well as the animals. Not only that, on average you need about 3 kg of feed per 1 kg of meat. Some types of meat, like beef require a shocking 25 kg. A large portion of our grain production goes towards livestock. The majority of soy goes to feed livestock as well. You also end up using 50 000 liters of water for 1kg beef, versus only 1000 liters for 1kg wheat or 2000 liters for 1kg soy or rice.

When it comes to methane, you have to factor in the methane from plant production AND the livestock. If you just compare livestock farts to grain production emissions, you're not factoring in every variable. In a hypothetical world where every human has a plant-based diet, the amount of plant material humans eat would increase by an additional 600 calories per day, but the amount used to feed animals would decrease by 100%. So there's a huge difference in how much additional plants you have to produce to support a plant-based diet versus a meat-based one. You have to factor in the methane from the production of the plants used to feed the animals as well as the methane produced by the animals themselves.

By no means do you have to eat three times as much when living off of a plant-based diet, nor do you need to drink and additional 48 000 liters of water per kg you eat. So there's no way that producing that 1kg meat can somehow end up using less water or plants, or producing less emissions than a plant-based diet. On top of all of this, meat production requires huge amounts of antibiotics, which goes into the water and increase the amount of antibiotic-resistent bacteria.

plumquat on May 28th, 2021 at 15:35 UTC »

This is a misleading title.

LilyAndLola on May 28th, 2021 at 12:59 UTC »

This is dumb, the main problem from livestock isn't methane, it's land use and water pollution. We are currently in a biodiversity crisis as well as a climate crisis, and the biodiversity crisis can have just as bad effects as the climate crisis. The main cause of species loss is habitat loss and the main reason humans clear natural habitat is to make room for livestock. Livestock farming is also the leading cause of eutrophication, a process which depletes oxygen in the waters of lakes, rivers and oceans to the point where no animal can survive. There are many other problems caused by raising livestock, such as the removal of predators from ecosystems and the spread of disease caused by fish farming, as well as many others. Assuming that simply reducing methane emissions is enough is so ill thought through.