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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On Election Day, a broad coalition of conservationists, labor, and others helped defeat a ballot initiative to repeal Washington State's Climate Commitment Act. The act, passed in 2021, is the state's state's primary vehicle for reducing emissions and pollution and a major source of funding for clean energy infrastructure and climate initiatives.

Billy Wallace, political and legislative director with the Washington and Northern Idaho District Council of Laborers, said passage would have meant the loss of as many as 45,000 clean-energy jobs.

"We started building a coalition, and it ended up being a little over 600 groups, from labor, from environmental. The Catholic Church was on it, We had 21 of the 29 tribes sign on. So it was a very diversified coalition that came together to save this funding." he said.

Initiative 2117 was one of four ballot measures backed by the Let's Go Washington PAC funded primarily by conservative hedge-fund manager Bryan Heywood. Wallace said that over the next 8 years, Climate Commitment Act investments would create 45,000 jobs in Washington State.

Wallace added the coalition faced an uphill battle to help the public understand that jobs and the environment were both on the line.

"These are the investments, even in schools, clean air, clean water. And once we figured out we got to educate the people on what's going on, it was complicated. It was confusing for the general public. So we raised $18.4 million for this campaign from that big coalition," he continued.

Climate Jobs Washington and its member unions formed a coalition to protect the act. Wallace said labor organizations were instrumental in passing the original measure three years ago.

"It was crucial for our members. Our members work in the building trades. About 75%, 80% of the work we do is on prevailing wage work in transpo[rt]. So it was a no-brainer for us to jump in," he added.

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New research finds Maryland leading the nation in reducing greenhouse gas emissions.

Environmental Protection Agency data show between 2005 and 2022, greenhouse gas pollution fell in 44 states and the District of Columbia. Maryland saw the largest reduction at 36%, followed by D.C., Maine, New Hampshire and Georgia. Only six states saw emissions increase.

Emily Scarr, senior advisor for the Maryland Public Interest Research Group, said the wide variation between states shows local policy matters.

"It's really evidence that states and regions have a lot of control on their greenhouse gas emissions," Scarr explained. "Showing ways that we can continue to reduce emissions, as well as showing warning signs of things that states do that can actually take us in the wrong direction."

The reductions nationwide are largely attributed to the retirement of many coal-fired power plants. Maryland has shuttered seven coal plants since 2012, with two still operating.

The report looks at emissions data from power generation, industry, transportation, agriculture, residential and commercial sectors. Maryland saw emissions reductions in every category except for the commercial sector, which includes commercial buildings, landfills and wastewater treatment centers. Scarr pointed out fossil-fuel-based winter heating is driving emissions in the commercial sector.

"The majority of those emissions are actually coming from heat for commercial buildings," Scarr observed. "That's a specific place where, if properly implemented, the Building Energy Performance Standards can start holding commercial building owners accountable."

The Maryland Department of the Environment will collect energy-use data from buildings larger than 35,000 square feet in 2025, to develop energy performance standards based on those numbers. The state has set a 2040 target for large buildings to have net-zero emissions.


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Community members in Seattle had a unique opportunity to weigh in on the policies guiding the city's climate goals.

In 2019, the City of Seattle passed the Green New Deal Resolution and Green New Deal Executive Order, with the goal of eliminating climate pollution by 2030.

To help guide that process, the initiative's oversight board supported community assemblies.

Peter Hasegawa is the organizing director at MLK Labor and co-chair of the Green New Deal Oversight Board.

He said the idea behind the community assemblies was to do deep listening with many different community members.

"To have the opportunity to present information and get feedback," said Hasegawa, "and have people think about solutions together over a longer period of time, was appealing to us because we thought we could get higher quality feedback."

MLK Labor and Urban League of Metropolitan Seattle hosted the assemblies.

The goal was to ensure that people on the front-lines had their voices heard, and were at the table as the city crafts policies going forward.

Faduma Fido is lab leader with the People's Economy Lab, which helped support the community assemblies.

She said they're piloting this type of engage at the city level because people are tired of going to listening sessions.

She said the assemblies provide a more empowering setting, with people compensated for their time and eating meals together. Fido said they want to bring democratic practices like these back.

"There's an appetite and willingness now to empower the citizens," said Fido, "empower communities to practice democracy beyond the ballot box, because often that tends to be very polarizing."

Hasegawa said they heard from a variety of people over the three sessions.

In the first, they heard about people's experiences being affected by extreme weather, such as the 2021 heat dome, and a freeze last winter that caused many people's pipes to burst.

In the second session, they heard about wins on the ground to protect people and workers from the effects of climate change.

Hasegawa said in the third, they brainstormed about what the city and local labor movement can do about climate change.

"In certain ways that ended up being the easiest session," said Hasegawa, "because there was a very high level of consensus that what workers in Seattle want is to be protected from extreme weather, they want to be protected from heat and smoke, and bursting pipes, and they want to be protected whether they work in a building or outside or in a home."




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