By Gabriella Sotelo for Sentient.
Broadcast version by Judith Ruiz-Branch for Illinois News Connection reporting for the Sentient-Public News Service Collaboration

Nitrous oxide (N₂O) emissions from agriculture are not only coming from soil. They’re also flowing through the streams that run alongside farms, a recent study finds. Researchers at the University of Minnesota and University of Illinois discovered more than one-third of regional nitrous oxide emissions were measured from streams.

While often overshadowed by the more widely known greenhouse gases like carbon dioxide and methane, nitrous oxide is the third-largest contributor to greenhouse gas emissions. Nitrous oxide also has an EPA-rated “Global Warming Potential” 273 times that of carbon dioxide (over a 100-year timescale), and is a significant contributor to ozone depletion. This means that even small amounts of nitrous oxide emissions can have a disproportionately large impact on global warming. And the flip side is also true: taking some action, including better manure management and eating less meat, can have a big climate impact for the better.

The discovery highlights a previously overlooked pathway for nitrous oxide to enter the atmosphere: as agricultural soils undergo the process of nitrification and produce nitrous oxide, the gas is transported via runoff into nearby streams. During the nitrification process, bacteria in soils break down ammonia — in this case from fertilizers — into nitrates that can produce nitrous oxide gas. While this gas may be released immediately from the soil, it can also become trapped in the soil or dissolve in water, only to be carried into streams during rainfall or snowmelt.

 “What we basically found is there [are] other pathways, and this stream emission could be important,” Zhongjie Yu, hydrologist and researcher in the study, tells Sentient.

Traditionally, when researchers consider nitrous oxide emissions from agriculture, they focus on soil. Excess nitrogen from fertilizers accumulates in agricultural soil, where it can be transformed into nitrous oxide, and released directly into the atmosphere. However, this new study suggests that emissions from streams — carrying runoff from agricultural fields — can be just as important, if not more so, in certain regions. Factory farms can be a major driver of this issue, as these operations produce large amounts of waste, composed partly of nitrogen.

When researchers consider initial nitrous oxide emissions, it’s often in the context of fertilizer input to soil. This excess nitrogen accumulates in agricultural soil, and can then lead to the direct release of nitrous oxide into the atmosphere.

Though the study used only the University of Minnesota’s Tall Tower Trace Gas Observator to sample air emissions, Yu and his research team are confident about the data.

“We found that N₂O is emitted from streams, but we believe it’s originally from fertilizer nitrogen. It is just carried by water, and gets emitted from those aquatic systems. It’s not saying it’s a natural source, but it’s still related to fertilizer nitrogen. But it just provides another pathway that N₂O gets lost from some land to the atmosphere.”

Yu also emphasized that agriculture is the dominant source of human-caused nitrous oxide emissions. This study not only challenges the conventional understanding of agricultural emissions, but also underscores a broader issue: agricultural runoff is not just a water quality problem — it is also a major contributor to climate change.

Nitrous Oxide: the Lesser Known Climate Threat

Human activities are significant contributors to nitrous oxide emissions. While other natural sources, such as the ocean, also release nitrous oxide, agricultural practices — particularly fertilizer application — are by far the largest contributor of anthropogenic emissions.

This gas is primarily produced when nitrogen-based fertilizers and manure are applied to agricultural soils. Microbes in the soil convert this nitrogen into nitrous oxide through processes such as nitrification and denitrification. The situation is made worse by the practices of industrial farming, which rely heavily on the use of synthetic fertilizers and animal waste.

Around 12 million tons of nitrogen are applied to crops each year in the United States. An EPA report found that agricultural soil management — like fertilizer use and other practices that boost nitrogen levels in the soil — accounts for nearly 75 percent of the United States’ nitrous oxide emissions. Within the agricultural sector itself, it makes up almost half of all emissions.

These soil management practices are primarily intended to optimize crop production, but much of the land is used for growing farm animal feed and biofuel crops. In 2020, only a small fraction of corn grown in the U.S. — less than two percent — was used for direct human food. Around 31 percent was dedicated to biofuels such as ethanol, while the majority, around 35 percent, went toward feeding livestock. With global meat consumption steadily rising, the demand for animal feed is expected to increase, further driving the need for feed crops like corn — along with higher fertilizer use and a corresponding rise in nitrous oxide emissions.

And now, the source of these emissions isn’t just the soil. Stream emissions can contribute to a much larger portion of annual nitrous oxide emissions than researchers previously thought.

“The high contribution of stream emissions suggests that soil emissions may have been overestimated in current regional nitrous oxide budgets,” Yu writes.

Yu points out that the link between agricultural runoff and stream emissions has often been overlooked in past research. Traditional methods use soil chambers to measure nitrous oxide emissions, a method that places a closed chamber over the soil, in order to capture any gases emitted from it. This approach primarily measures how much nitrous oxide is released directly from the soil, but misses the nitrogen that leaches out of the soil and flows into water systems, where it can then be converted into nitrous oxide and emitted to streams.

The Bottom Line

The source of nitrous oxide emissions from agriculture is more complex than scientists once thought. While traditional efforts to reduce nitrous oxide emissions have focused mainly on fertilizer management and improving soil efficiency, this new discovery emphasizes the importance of looking at the entire agricultural system, including runoff into streams. If the number of factory farms continue to rise, there is likely to be a rise in nitrous oxide pollution, particularly in streams, due to greater fertilizer use and runoff.

Yu mentions that improving water and nutrient management not only benefits water quality, but can also be a crucial tool in reducing greenhouse gas emissions. Fertilizer and manure runoff, especially from factory farms, can carry large quantities of nitrogen into waterways, which may then be converted into nitrous oxide — further complicating efforts to mitigate emissions from agriculture.

“We need to be a little bit careful here, because that water gets leached from surface soil and can end up in streams and rivers, carrying a lot of that greenhouse gas to those systems and having an impact there,” Yu says.


Gabriella Sotelo wrote this article for Sentient.


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By Nina Misuraca Ignaczak for Planet Detroit.
Broadcast version by Chrystal Blair for Michigan News Connection for the Planet Detroit-Public News Service Collaboration.

Darwin Baas surveys Kent County’s landfill from the cab of a county truck, watching the steady arrival of waste-hauling vehicles dumping drywall, sofas, home clean-outs, and bagged leftovers tumbling out by the ton. An average of 800 of these trucks arrive every day. The South Kent Landfill — just outside Grand Rapids — is now about 95% full.

“Everything up here is going to try to kill you,” he tells visitors, gesturing toward the trash compactors and bulldozers weaving between soft spots of shifting debris. But it’s not just the machinery that makes this place dangerous — it’s the system itself, designed to make waste disappear with maximum convenience and minimum cost.

Baas, director of Kent County’s Department of Public Works, has spent the last 11 years trying to bend that system in a new direction. Under his leadership, Kent County has voluntarily captured methane from its landfill, continued to operate Michigan’s only municipal waste-to-energy incinerator, and proposed an ambitious Sustainable Business Park to divert food and yard waste, recover recyclables, and incubate circular economy businesses. 

But most of the county’s 600,000 tons of annual municipal solid waste still ends up here.

Kent County is among a minority of counties in Michigan managing waste through a publicly operated system. The vast majority of landfills statewide — 49 of 60 — are privately owned and profit-driven, further reinforcing the incentive to bury. Waste Management owns and operates dozens of landfills across Michigan. Baas sees this as a structural barrier to meaningful change.

“We need public-private partnerships,” he said. “The investments that need to be made are long-term — that’s not something the private sector is going to do on its own.”

The challenge Baas faces isn’t just operational — it’s systemic. As Michigan works to meet its climate goals, one of the most potent sources of greenhouse gas emissions is hiding in plain sight: landfills.

When food, yard waste, and other organic materials are buried, they decompose without oxygen and produce methane — a greenhouse gas that traps more than 80 times as much heat as carbon dioxide over a 20-year period. Though less visible than smokestacks or tailpipes, landfills are among the state’s largest sources of methane emissions, trailing only the fossil fuel sector.

Michigan recently overhauled its solid waste law, in part to address methane leaks. But even with new rules on the books, economic incentives still favor the cheapest option: burying waste. 

Baas sees this as a core flaw in how Michigan manages its garbage — and a missed opportunity. In Kent County, he’s built an integrated system that prioritizes material recovery, energy generation, and composting over landfilling.

However, those systems are more expensive upfront and require initial and ongoing investment, which means aligning public infrastructure, private capital and long-term planning in ways Michigan’s current system doesn’t support.

At the heart of the issue is a tension between innovation and inertia — between new solutions and a regulatory and economic system still structured around cheap disposal. Michigan has the opportunity to lead on waste recovery, Baas argues, but doing so will require more than technical upgrades. It will demand a fundamental rethinking of how the state handles waste — and who bears the burden.

A new regulatory push

Michigan overhauled its solid waste law in 2022, in part to address methane leaks. The updated Part 115 requires all landfills — regardless of age or size — to self-monitor methane emissions and fix leaks through patching or installing gas collection systems if they exceed thresholds. New technologies, including satellite mapping and drones, offer more precise ways to detect emissions than traditional walkover surveys — but adoption remains slow.

Sniffer Robotics, an Ann Arbor-based company, developed the only EPA-approved drone for landfill methane detection. Its technology, already in use at Arbor Hills Landfill, can locate leaks faster and more accurately than older methods. Yet despite promising results, cost barriers and procurement hurdles have limited uptake across the state.

Michigan’s new rules also impose faster compliance timelines: sites must correct surface emissions within 90 days or begin designing a full gas collection system. Currently, Michigan landfills use a mix of active and passive gas systems — active systems vacuum methane to flares or energy generators. In contrast, passive systems may vent it directly into the air. Sites without active collection may eventually be forced to upgrade.

Tim Unseld, a solid waste engineer with the Department of Environment, Great Lakes, and Energy (EGLE), said two landfills without gas systems have already detected surface emissions and made repairs. But those fixes may not last. “Once enough landfill gas is generated, it will follow the path of least resistance to escape,” he said. Ongoing repairs can become costly — pushing operators toward installing full recovery systems, particularly if they can sell the captured methane as energy.

Environmental advocates argue the reforms don’t go far enough. “We’re the sixth-largest producer of landfill methane emissions, even though we’re only the 10th or 11th most populous state,” said Mike Garfield, executive director of the Ecology Center. “The basic reason is simple: We’ve made it too easy and too cheap to landfill waste.”

Garfield wants the state to adopt enforceable best practices across the board — including tighter flare controls, real-time monitoring, and mandatory adoption of tools like Sniffer’s — and points to the 2022 Arbor Hills consent judgment as a model.

Arbor Hills, owned by GFL Environmental, is the largest landfill in the state in terms of the amount of waste in place, according to EPA. It has faced years of complaints and violations tied to odor, gas migration, and leachate issues. So far, however, EGLE has not moved to apply those stricter terms statewide.

“The Part 115 amendments of 2023 include what EGLE considers best practices,” said agency spokesperson Josef Greenberg, adding that the state’s current focus is on implementation.

The economics of food waste disposal

Food waste is the largest single component of Michigan’s municipal waste stream by weight. Yet efforts to keep it out of landfills face a steep uphill climb — in large part because the system is built to reward the opposite.

Disposal fees are typically based on weight, creating a strong financial incentive for landfills owners to accept heavier materials like food waste. “This is really carbon-rich material — it generates methane, and they can use that methane to drive biogas-based processes,” Desirée Plata, an environmental engineer at MIT.

It’s a perverse incentive, she noted, especially as Michigan aims to reduce methane emissions. Instead of rewarding diversion, the current system reinforces disposal. “We’re paying for disposal by the ton, not by environmental outcome,” she said. According to EPA data, 35 out of 60 landfills in Michigan — nearly 60% — have landfill gas-to-energy projects. 

That tension sits at the heart of Baas’s frustration. He’s spent years trying to reorient the local waste system around recovery. “I’ve been told I’m an oddity in the waste industry,” Baas said. “Most people don’t see the system this way.”

Waste recovery adds expense and faces adoption challenges, said Debora Johnston with Waste Management. “Capturing landfill gas generates revenue to help operators keep disposal costs down, helps protect our environment, and creates a renewable energy source for our local community,” she said.

“But separating out organics like food waste is expensive.” Indeed, the estimated cost for Kent County to meet the needs of a community of 640,000 to process 400,000 tons of mixed waste would exceed $400 million.

Plata said one of the most effective actions municipalities can take today is to fund composting. “Every municipality on the planet should be funding compost programs,” she said. “It’s one of the easiest things we can do to fight climate change — and it works.”

But Johnston points out the challenge of getting people to change their ways.

“Most communities are finding participation in recycling programs to have plateaued,” Johnston said. “And new organics collection and drop-off sites face many of the same challenges.”

That’s why Baas sees single-stream processing — separating out organics like food waste and recoverable items like recyclables and metals after pickup — as the path forward.

Despite setbacks, including the withdrawal of a private-sector partner, Kent County is moving forward with its Sustainable Business Park — a proposed 250-acre campus on county-owned farmland next to the nearly full South Kent Landfill.

The county has made a deliberate decision not to site a new landfill there and instead repurpose the land for recovery infrastructure that could process food and yard waste — which has been banned from landfills in Michigan since 1993.

“We’re past the point of building another landfill,” Baas said. “We’re trying to do something different.” Still, he acknowledges the economics won’t shift without public investment and new rules. 

“We’ve determined that the highest, best use for these organics was mission critical,” he said. “But unless you change policy and infrastructure to make it go somewhere else, food waste will keep going to landfills — the lowest hanging fruit economically.”


Nina Misuraca Ignaczak wrote this article for Planet Detroit.


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Wyomingites are split on what is causing climate change, but 86% of residents in the state agree it is happening, according to a new survey.

Kristen Landreville, a researcher at the University of Wyoming, surveyed a group of state residents and found 39% think climate change is caused by humans and 47% think it is not. Causes aside, more than 80% of respondents said their communities should plan for shifting water resources.

"Whether it's local community officials, Wyoming state legislators, Wyoming governor, we see high numbers of people saying, 'We want to do more to adapt to the changing water resources in our state,'" Landreville reported.

Landreville added most people are worried about future water threats. Fewer than half of respondents said their local area is already feeling the effects of changing water resources but about 70% think the same areas could be affected in the future.

The survey also found major misconceptions about public opinion. While eight of 10 respondents believe communities should plan for changes to water resources, only half believe their community feels the same way.

"That gap of perception can create this kind of 'spiral of silence' where people don't think that it's safe to share their opinions," Landreville explained. "I think it's important for us to try to make people feel more open to share those thoughts, because that's how we get the ball rolling in terms of action, is we need to be OK to talk about it."

Despite the gap in perception, more than half of Wyomingites are optimistic the state can overcome future challenges surrounding water and related hazards.


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By Jessica Scott-Reid for Sentient.
Broadcast version by Nadia Ramlagan for West Virginia News Service reporting for the Sentient-Public News Service Collaboration

When it comes to tackling climate change and industrial animal agriculture, a long-standing debate continues to divide advocates - is it better to focus on individual dietary shifts, or demand systemic change? Over the last decade or so, environmental and animal welfare organizations have grappled with how to combine individual behavior change with a broader push for collective action. Is it more effective to urge consumers to eat less meat, or to target meat and dairy companies to transition toward plant-based alternatives? Are individual shopping choices more impactful, or should we prioritize boycotts and pressure campaigns through grassroots activism?

A new report from the World Resource Institute reveals that both strategies can - and in fact must - work together. To combat climate change, the report finds, collective change and individual action require a joint effort.

"This research shows that people really can't do it alone," Mindy Hernandez, one of the authors of the WRI report, tells Sentient. "They need help in order to realize the very significant emissions reductions that are possible." Rather than getting caught up in the idea that "'corporations need to do something, or nothing matters,' systems-level players, specifically policy and industry actors, have a massive role to play." At the same time, Hernandez adds, "that does not give individuals a free pass."

The Surprising Origins of the 'Personal Carbon Footprint'

The idea of a "personal carbon footprint" didn't come from climate scientists or environmental advocates - it actually came from Big Oil, as a means of placing the onus on us. In 2004, British Petroleum (BP) introduced the carbon calculator, reframing the climate crisis as a matter of personal responsibility. The message was simple: Don't look at us. Look at yourself.

We're still grappling with the legacy of that messaging. A little more than 20 years later, global emissions continue to rise yet conversations around food and climate tend to be framed in terms of individual choices - both the effective ones like eating less meat and the not-so-effective ones for climate emissions, like buying local, "climate-friendly," "regenerative" or organic.

Meanwhile, the beef industry continues to pump out emissions, with little political will to tackle these emissions in a meaningful way.

Impact of Diet on the Planet

Around a third of global greenhouse gas emissions come from food, and most of those food-related emissions are driven by meat, especially beef. Americans and other Global North countries must eat less meat and shift to more plant-forward diets, the research suggests. "Plant-based foods - such as fruits and vegetables, whole grains, beans, peas, nuts, and lentils - generally use less energy, land, and water, and have lower greenhouse gas intensities than animal-based foods," according to the United Nations.

WRI's research also finds that "pro-climate behavior changes" are enough, potentially, to "theoretically cancel out all the greenhouse gas (GHG) emissions an average person produces each year - specifically among high-income, high-emitting populations." One of those climate-crucial behaviors, the research reveals, is cutting back on meat and dairy - especially beef and lamb.

Organic or regenerative food have various merits, but these do not include a reduction in climate emissions for beef, because organic and regenerative cattle ranching requires more land, and land has a climate emissions cost. Ultimately, none of these personal actions come close to the environmental impact of shifting away from meat and other animal-sourced products. "Full veganism can save nearly 1 ton of CO2 annually, about a sixth of the average global citizen's total emissions. But even reducing meat intake captures 40% of that impact," the report states.

Why Individual Change Is Not Enough

The WRI research also makes a larger point: focusing solely on individual behavior is not sufficient on its own. Without systemic change, we unlock just a fraction - about 10 percent - of our true climate action potential.

The other 90 percent, according to WRI, "stays locked away, dependent on governments, businesses and our own collective action to make sustainable choices more accessible for everyone. (Case in point: It's much easier to go carless if your city has good public transit.)"

Consider a student working to decrease their individual climate impact by eating less meat, WRI's Hernandez suggests. A systemic action the student could take would be to advocate for the school to adopt Meat Free Mondays or WRI's Cool Food Pledge, a program that helps organizations reduce the climate impact of their food offerings by shifting to plant-rich menus.

"Suddenly it's really easy for that student to keep their commitment to eating less meat," says Hernandez, and the collective emissions of the larger student body also then decreases.

The key is to have climate action, at both individual and systemic levels, working in unison. "Systemic pressure creates enabling conditions, but individuals need to complete the loop with our daily choices. It's a two-way street," the WRI researchers write. "Bike lanes need cyclists, plant-based options need people to consume them." And when more of us adopt these behaviors, "we send critical market signals that businesses and governments respond to with more investment."

Taking Action During Difficult Times

As the current administration continues to roll back environmental protections, it's a crucial time for both individual and collective action, Lauren Ornelas, founder of the nonprofit Food Empowerment Project, tells Sentient. "We can't say 'I can rely on the government to pass regulations that are good for the environment or that are good for the welfare of animals,' or 'I can rely on my policymakers to do those things.' It's kind of up to us," she says, "and this is the best time to acknowledge that in every aspect [where] we actually have power."

For those who care about food system impacts, that power can be found in what we choose to eat. "Food choices are always empowering," says Ornelas. So is taking part in a broader collective action, she adds, "to make sure that we are joining our voices with others to demand change."

And what could this look like? "Focus on the one thing that you think you can do in your household," Hernandez says." And then, think about what is the one systems-level thing you can do," like joining a local environmental or food justice group. Shifting diets away from meat and dairy may not solve the climate crisis alone, but eating less meat can be one empowering individual choice that can be made that much stronger by collective action.


Jessica Scott-Reid wrote this article for Sentient.


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