By Seth Millstein for Sentient.
Broadcast version by Eric Galatas for Colorado News Connection reporting for the Sentient-Public News Service Collaboration
In the 10,000 years since humans first developed animal agriculture, livestock farming has become central to modern society. Unfortunately, it's also become one of the biggest drivers of climate change and environmental destruction. Animal farms create a staggering amount of air, water and land pollution, and with the consequences of climate change worsening by the year, addressing the environmental impacts of livestock farming is more important than ever.
Global warming is an enormous part of climate change, but it's not the only part. The concept of climate change encompasses not only rising global temperatures, but all sorts of other changes to the natural composition of Earth and its atmosphere, such as water pollution and land degradation. Here are some of the ways livestock farming contributes to those changes.
But First, a Brief Summary of Greenhouse Gasses
One of the biggest ways livestock farming contributes to climate change is through the emission of greenhouse gasses, which trap heat in the Earth's atmosphere and cause global temperatures to rise. Insofar as livestock is concerned, there are three greenhouse gasses in particular of note.
- Carbon dioxide (CO2): The "main" greenhouse gas, carbon dioxide comprises around 80 percent of all greenhouse gas emissions. CO2 exists naturally in the atmosphere and regularly circulates from the Earth to the air as part of the carbon cycle; however, the burning of fossil fuels and other human activities releases additional CO2, throwing off that cycle and increasing global temperatures. CO2 can stay in the atmosphere for hundreds of years.
- Methane (CH4): Methane only accounts for 11 percent of global greenhouse emissions, and unlike CO2, disappears after a relatively brief 12 years. However, it's much more effective at trapping heat in the atmosphere: over a 100-year period, one pound of CH4 has 28 times the global warming potential as one pound of CO2.
- Nitrous oxide (N2O): Nitrous oxide only makes up six percent of greenhouse gas emissions, and exists naturally on Earth as part of the nitrogen cycle. It remains in the atmosphere for about 121 years on average after it's emitted, and its global warming potential is a whopping 265 times greater than that of CO2 over a 100-year period.
Because there are multiple greenhouse gasses with different warming potentials, greenhouse emissions are commonly converted to and measured in CO2-equivalents, or CO2-eq.
In various ways and to varying degrees, livestock farming emits all of the aforementioned greenhouse gasses. Here's how.
How Livestock Farming Creates Methane Emissions
Livestock are a significant source of methane emissions, thanks to a natural biological process called enteric fermentation. Cows, sheep, goats and other ruminant livestock have microbes in their digestive systems that decompose and ferment the food they eat, and
methane is a byproduct of this fermentation process.
That methane is released into the atmosphere when the animals burp or fart, and it's also contained in their urine and manure. One cow can produce up to
264 pounds of methane every year, and it's estimated that in total, enteric fermentation from ruminant livestock is responsible for 30 percent of
global anthropogenic methane emissions.
How Livestock Farming Leads to Pollution from Manure
Farm animals produce around
450 million tons of manure every year, and figuring out what to do with it is a major challenge for livestock farmers. Some farms
store manure in large piles, landfills or lagoons - known as "settlement ponds" - while others simply dump it onto cropland and use it as untreated fertilizer.
All of these management methods result in the release of methane and nitrous oxide, which manure also contains. When manure is stored in an environment with insufficient oxygen, as is often the case with landfills and lagoons, it undergoes a
process known as anaerobic decay, and releases nitrous oxide and methane into the air as a result. In addition, structural failures or extreme weather events often cause the
manure in settlement ponds to leak into nearby soil and waterways.
When manure is used as fertilizer, it releases nitrogen into the soil. That's the point of fertilizer, as plants need a certain amount of nitrogen to grow. But when farms use this type of fertilization as a disposal method for excess manure, they often over-apply it to the crops in question, which causes the soil to absorb more nitrogen than is necessary.
You might wonder why it matters if soil contains too much nitrogen. There are two intertwined reasons: nutrient runoff and soil erosion.
Nutrient Runoff
Nutrient runoff occurs when rain, wind or other environmental forces disrupt soil and carry it into nearby waterways. When that soil has been fertilized with untreated manure, it pollutes the water in question, both with nitrogen and other toxins that are common in manure, like phosphorus.
Nitrogen and phosphorus both stimulate algae growth, and excessive algae growth in a body of water leads to harmful algal blooms.
As their name implies,
harmful algal blooms have a host of damaging environmental consequences. They release toxins that kill aquatic life and poison the drinking water, which can cause serious illness
and even death in humans. Algal blooms reduce the amount of dissolved oxygen in the water, which aquatic life relies on, and prevent light from penetrating the water's surface, thus choking the life out of coral reefs and other aquatic plants that are crucial to Earth's ecosystems.
Soil Erosion
Nutrient runoff is exacerbated by another consequence of livestock farming: soil erosion. This is when topsoil particles become loosened and detached, which diminishes the quality of the soil and makes it much more susceptible to nutrient runoff.
A degree of soil erosion occurs naturally, but livestock farming greatly accelerates it in a few ways. One is overgrazing, which is when livestock graze on pastures for extended periods without the pastures being given time to recover.
The hooves of cows, goats and other ruminant livestock can erode the soil as well, especially when many of them are grazing in one place.
In addition to making nutrient runoff more likely,
eroded soil is less fertile and can support fewer forms of plant life. It is also worse at retaining water, which can
increase the risk of drought.
Deforestation Due to Livestock Farming
It's impossible to assess the environmental impacts of livestock farming without also discussing deforestation - the practice of permanently clearing out trees from forested land and repurposing the land for other uses.
Humans deforest around 10 million hectares of land every year, and
41 percent of tropical deforestation is carried out to make way for cattle pastures.
Deforestation is a monumentally damaging practice, and exacerbates all of the aforementioned impacts of livestock farming: greenhouse emissions, nutrient runoff and soil erosion.
Greenhouse Emissions Caused by Deforestation
When forested land is cut down, greenhouse emissions increase in two ways - one temporary, one permanent.
Trees absorb and store carbon dioxide from the atmosphere, which makes them an indispensable resource for reducing global temperatures. When they're cut down, however, all of that carbon dioxide is released back into the air. What's more, the absence of trees in a previously forested area means that, for an indefinite period of time, any atmospheric carbon dioxide that would otherwise have been sequestered by the trees remains in the atmosphere instead.
The greenhouse gasses emitted during livestock-driven deforestation, combined with the gasses emitted by livestock farms themselves, account for
11-20 percent of all greenhouse gas emissions worldwide. In the Amazon, which has traditionally been one of the world's largest sequesterers of carbon, so much land has been deforested that the rainforest is in danger of
becoming a net emitter of carbon instead.
Soil Erosion and Nutrient Runoff Caused by Deforestation
In forested land, trees play an important role in protecting and preserving the soil. The canopy they provide protects the soil from the sun and rain, while the trees' roots help hold the soil in place.
Needless to say, clearing all of the trees in a forested area means that the soil doesn't get any of these benefits. As a result, the soil becomes eroded even before any livestock might step foot on it, which in turn increases the likelihood of nutrient runoff and water pollution.
The Bottom Line
The environmental impact of livestock farming can't be ignored. The sector's contribution to deforestation, habitat loss and pollution of all kinds significantly exacerbates climate change. Absent a
significant reduction in global meat consumption, it will continue to present a formidable challenge to the long-term health of Earth and its many inhabitants.
Seth Millstein wrote this article for Sentient.
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By Carolyn Beans for Lancaster Farming.
Broadcast version by Mark Richardson for Keystone State News Connection reporting for the Lancaster Farming-MIT Climate Change Engagement Program-Public News Service Collaboration
At Mountain View Holsteins in Bethel, Pennsylvania, owner Jeremy Martin is always working to make his dairy more efficient.
Currently, he has his sights set on a manure solid-liquid separator. He'd like to use the solid portion of his manure as bedding for his 140 cows and the liquid as fertilizer.
But the project is pricey - he expects the equipment alone will run around $100,000. So Martin hopes to defray the cost through grant funding for dairy projects that reduce greenhouse gas emissions. Removing much of the solids from manure reduces the feed for the methane-producing microbes that thrive in the anaerobic conditions of liquid manure.
The approach is just one of many dairy practices now considered "climate-smart" because they could cut production of climate-warming gases.
For Martin, a manure separator wouldn't be possible without a grant.
"Once it's in place and going, I think some of these practices will pay for themselves, but the upfront cost is more than I can justify," he says. "If there's money out there to pay that upfront cost to get started, it makes sense to me to do it."
Across Pennsylvania, dairy farmers are learning more about climate-smart practices and funding opportunities, and weighing whether these changes are really sustainable for their businesses as well as the environment.
The Latest Buzzword
USDA has defined climate-smart agriculture as an approach that reduces or removes greenhouse gas emissions, builds resilience to the changing climate, and sustainably increases incomes and agricultural productivity.
"Before climate-smart was a thing, we called it conservation. We called it stewardship," says Jackie Klippenstein, a senior vice president at Dairy Farmers of America.
Indeed, long before the Food and Agriculture Organization of the United Nations coined the term "climate-smart agriculture" in 2010, Pennsylvania dairy farmers had adopted many of the practices that now fall under the label.
For dairy, climate-smart practices largely include strategies that reduce greenhouse gases emitted from cows, manure or fields. Tried and true conservation practices like cover cropping and reduced tillage count.
So do newer practices like using the feed additive Bovaer to reduce methane production in a cow's rumen, or precision nitrogen management to reduce nitrous oxide emissions from fields.
Paying for Climate-Smart
"Margins are very tight on the dairy farm," says Jayne Sebright, the executive director of the Center for Dairy Excellence, a public-private partnership to strengthen Pennsylvania's dairy industry. "Some of these (climate-smart practices) are good for the climate, but they don't make good economic sense until they're subsidized."
In 2022, the center joined a Penn State-run program called "Climate-smart Agriculture that is profitable, Regenerative, Actionable and Trustworthy" to provide dairy farmers with funds for switching to climate-smart practices.
CARAT was launched with a $25 million USDA Partnerships for Climate-Smart Commodities grant, but the future of the Pennsylvania project is in doubt. In April, USDA canceled the partnership program, suggesting that recipients reapply to a new USDA initiative called Advancing Markets for Producers.
Over 60 dairy farmers across Pennsylvania, including Martin, had already applied and been accepted into the first phase of CARAT. This initial phase was intended to help farmers identify the best climate-smart practices for their operations. In the second phase, farmers would have applied for funding to implement those practices. One farmer was already paid for his project before the USDA canceled the partnership program.
"There are fewer funding sources for climate-smart projects than in the last administration. However, private organizations and other entities are funding climate-smart projects," Sebright says. "Depending on what the practice is, (climate-smart) could also be conservation projects. It could be water quality projects."
Sebright suggests that dairy farmers also look for support through state-level funding, such as Pennsylvania's Resource Enhancement and Protection program, which offers tax credits for implementing practices that benefit farms and protect water quality.
Pennsylvania dairy farmers can also contact their county conservation districts to ask about funding opportunities for climate-smart projects, says Amy Welker, a project manager and grant writer for Pennsylvania-based Jones Harvesting, which operates Maystone Dairy in Newville and Molly Pitcher Milk in Shippensburg.
In the next year, Jones Harvesting plans to install a methane digester and solid-liquid separator at a site near Maystone Dairy. The digester is funded with an Agricultural Innovation Grant from the state and an Environmental Quality Incentives Program grant from USDA, along with private funds.
There's money out there for farmers who implement climate-smart practices, says Welker. But "you can't just look at one source."
Long-Term Payoffs
Ultimately, for climate-smart projects to make economic sense, they must continue paying for themselves long after the initial investment. One major goal of the USDA's Partnerships for Climate-Smart Commodities program was to develop markets where farmers adopting these practices could earn a premium.
Some dairy farmers might see that return in the carbon market. National checkoff organization Dairy Management Inc. and its partners have pledged to shrink the industry's net greenhouse gas production to zero by 2050. There are growing opportunities for companies working toward that goal in the dairy supply chain to pay farmers for their contributions.
Early last year, Texas dairy farmer Jasper DeVos became the first to earn credits through the livestock carbon insetting marketplace. DeVos earned carbon credits by reducing methane emissions with a feed protocol that included the feed additive Rumensin. Dairy Farmers of America then purchased those credits through Athian, a carbon marketplace for the livestock industry.
Increased Efficiency
Even without direct monetary payoff, many farmers who adopt climate-smart practices reap rewards in improved efficiency and productivity.
"When you look at climate-smart, you also have to look at what's farm smart," Sebright says. She suggests that farmers choose practices that benefit their farms, not just the climate.
A farmer might decide to put a cover and flare system on a manure pit, not only because it reduces methane emissions but also because it keeps rainwater out of the pit and reduces the number of times each year the pit must be emptied.
Andy Bollinger of Meadow Spring Farm in Lancaster County has been running a manure separator since 2009. The liquid fertilizes his fields, and a portion of the solids becomes bedding for his cows.
He estimates the system saves him at least $20,000 a year in bedding costs.
"We put a fresh coating of it onto the stalls that our cows lay in every day and scrape the old stuff out," says Bollinger, who is also the vice president of the Professional Dairy Managers of Pennsylvania. "It seems to work quite well, and it saves us from buying other bedding products."
No-till farming is also a cost saver because it reduces field passes with equipment, says James Thiele of Thiele Dairy Farm in Cabot, which has been 100% no-till for at least six years. The practice saves him money on fuel and herbicides.
"You're saving your environment, and you're also saving green," he says.
But Thiele questions whether some other climate-smart practices like methane digesters would be practical for his farm, which has 75 to 80 cows.
"I don't know if it'd be worth it for somebody as small as I am," he says.
"I think over the next few years, we'll rapidly see (climate-smart) tools become more available, and we'll see more organizations like DFA talking to our small to mid-sized farmers to make sure they understand they've got a place in this, they can benefit from it, and the practices and tools are affordable to them as well," Klippenstein says.
Weighing Climate-Smart
Many dairy farmers wonder whether some of the practices championed as climate-smart will really support their businesses.
Donny Bartch of Merrimart Farms in Loysville has adopted environmental practices from cover cropping to a manure management plan.
"I want to protect the environment. I want to keep my nutrients here on the farm and be sustainable for another five generations," Bartch says. "But we have to make sure that we're making the right decisions to keep the business going. And to do some of these (climate-smart) practices, the only way they pencil out is to have those subsidies."
There is also frustration with a system that rewards climate-smart improvements made today without acknowledging the contributions of farmers who were climate-smart before anyone put a name on it.
"You come around and want to start rewarding people for doing these things. You really need to start with the ones that have been doing it for a long time, but that's really not what happens," says Jim Harbach of Schrack Farms in Loganton, whose farm has been no-till for 50 years.
Climate-smart grant money and carbon credits are typically awarded for the implementation of new practices.
"It's just the unfortunate way that all of the policies and regulations were written," Sebright says. "What I would say is, if you do a climate-smart plan, maybe there are practices or things you can do to enhance or support or take what you're doing a step further."
Scientific Measurements on Real Farms
Some dairy farmers also want to know more about how climate-smart practices will affect their farms before jumping in.
Steve Paxton remembers participating in a government program to improve timber over 50 years ago on his family dairy, Irishtown Acres in Grove City. His family members were paid to climb up into their white pines and saw off many of the bottom branches.
The goal was to create a cleaner log. Instead, more sunlight shown through, which caused grape vines to climb up and topple the trees.
"The bottom line is, there was research done, it looked good, but it hadn't had enough time to follow through and see just really what the end results would be," Paxton says.
When Paxton sees estimates of how some practices might reduce greenhouse gases emitted from cows, he wonders how much of that research has been tested on actual dairies.
"I think some of it now is just kind of a textbook estimate of what's happening," he says.
More meaningful data is needed to show how climate-smart practices reduce greenhouse gases on individual dairies, Sebright says.
As part of the CARAT program, Penn State researchers planned to place greenhouse gas sensors on a dozen dairies and test how much greenhouse gas production falls as farmers experiment with different practices. The researchers intended to then use that data to build models that predict how those practices may affect emissions on other farms. They will still measure emissions this spring on one farm that is experimenting with a new approach for spreading manure in fields of feed crops.
"The real goal of (CARAT) is to have research that says, if you put a cover and flare (manure storage system) on a 500-cow dairy, this is how greenhouse gas emissions will change," Sebright says. "Or if you use Bovaer on a 90-cow herd, here's how this will affect greenhouse gas emissions."
Martin of Mountain View Holsteins has his own personal beliefs about where a dairy farmer's responsibilities to the planet begin and end. But from a business perspective, he feels compelled to adopt climate-smart practices because he expects the industry will eventually require them.
"Climate concerns are coming whether I'd like it or not," he says. "So my thought is, I might as well get started on it while there's funding to do it."
Carolyn Beans wrote this article for Lancaster Farming.
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