By John Carey for the Proceedings of the National Academy of Science.
Broadcast version by Suzanne Potter for California News Service reporting for the Pulitzer Center-Public News Service Collaboration.
Methane, one of the most potent greenhouse gases, is the major component of the biogas that seeps from countless landfills and wastewater plants. It makes sense, then, to prevent that methane from escaping into the atmosphere-indeed, hundreds of solid waste facilities across the United States have done so for decades, either flaring the biogas to burn off the methane or burning the biogas to generate electricity or heat. That gives off carbon dioxide, but still greatly reduces the greenhouse gas potential, as methane is 80 times more potent than CO2 over the first 20 years after emission.
But in recent years, government and industry have found a more profitable way to use that biogas. Taking advantage of government subsidies and using technologies that strip out the CO2 and other gases-for example, absorbing CO2 with chemicals called amines-companies turn it into pure methane that can be injected into regular natural gas pipelines and distribution networks, seamlessly blending with the chemically identical fossil natural gas. In Europe, this gas is generally called biomethane; in the United States, proponents have rebranded it as "renewable natural gas" (RNG) "to highlight the role that RNG could and should play in displacing meaningful volumes of conventional natural gas," explains Dylan Chase, spokesperson for the Coalition for Renewable Natural Gas, an industry group.
A variety of interests are increasingly pushing for more RNG. Some environmental groups, scientists, and state governments see benefits in mitigating a potent greenhouse gas. Farmers see a new source of income. And for an oil and gas industry facing global efforts to phase out natural gas and other fossil fuels in the fight against climate change, RNG offers a possible reprieve-an opportunity to keep using the trillions of dollars' worth of pipelines and other natural gas infrastructure operating. This, even as some interest groups question the "renewable" label.
So, just how green are RNG initiatives? Are they helping in the fight against climate change, or are they merely enabling companies and others to pull in profits and prolong the use of natural gas infrastructure-and even fossil natural gas? It depends, not surprisingly, on who you ask.
Harvesting Power
Methane is produced wherever microbes break down organic material in the absence of oxygen. As a result, the gas bubbles into the atmosphere from countless sources-natural ones, like wetlands or melting permafrost, and human-created ones, such as landfills, manure lagoons, and wastewater treatment plants.
People have collected and used biogas for more than a century. One of first known applications was in the late 1800s at a leper colony in Matunga, India, according to Aaron Smith, agricultural economist at the University of California, Davis (UC Davis). "They captured gas from septic tanks to run a gas engine for pumping sewage, and also for lighting and cooking," he writes (1). In many developing countries, biogas is being promoted as a cleaner, safer fuel than wood or charcoal for heating and cooking (2).
To harness biogas, the basic idea is to seal up organic matter so that oxygen can't get in and to allow bacteria to dine on the waste. Landfills are typically already covered with clay, plastic liners, or dirt, so the gases are collected by drilling wells into the mounds of waste and putting in pipes through which the biogas can flow, sometimes aided by blowers. On large dairy farms or other animal operations, a slurry of manure is funneled into a structure called an anaerobic digester, where microbes produce gas that is piped away.
Policy Driven
Making RNG economically viable, though, requires another ingredient: government policy. The biggest driver has been a California program called the Low Carbon Fuel Standard, first implemented in 2011. The policy offers credits for greenhouse gas emissions avoided in transportation fuels to lower the average carbon intensity of those fuels. By early 2019, the value of those credits had soared to nearly $200 per metric ton of CO2 (or its equivalent) avoided (3).
The program offers a financial incentive to process landfill gas and other biogas into methane and inject it into pipelines. But the subsidy is much larger for methane captured from anaerobic digesters on dairy farms than from other sources, because the program gives credit for the emissions avoided from manure lagoons. Since the dairy biomethane counts as negative emissions (not just low or zero emissions, as in landfill gas), its value has reached a sky-high level of more than $70 per million British thermal units (MMBTUs)-a value that has ranged from 8 to 20 times higher than the price of fossil natural gas. "Dairy farms say they can make more money peddling RNG credits to California than they do making milk, which is kind of crazy," says Robert Howarth, professor of ecology and evolutionary biology at Cornell University and an expert in methane emissions.
These high prices have sparked a major boom in using manure and other waste to produce biomethane. In California, most of the more than 90 anaerobic digesters and methane capture systems now in operation have come online since 2019. And since anyone who injects biomethane into a pipeline that could conceivably connect to a California system linked to transportation can get California credits, the boom has reached across the United States.
California-based RNG company Brightmark, for example, is working with dairy farms in multiple states. "If you would've told me in 2016, when I founded the company, that we would now have more than 30 projects, I wouldn't have believed it," says Brightmark CEO Bob Powell. At one of Brightmark's projects, a large dairy operation in the Finger Lakes region of New York State named Lawnhurst Farms, biomethane production is a "win-win-win for our farm, our community, and the environment," states owner Don Jensen on the Brightmark website.
Some cities, meanwhile, are interested in harvesting biogas from food. It's much more effective to keep food waste out of landfills by placing it into anaerobic digesters instead (4)-if, that is, it's possible to collect it efficiently. Residents and businesses need to sort out the waste, and municipalities need to add curbside pickups, as a landmark California law that went into effect in 2022 requires cities to do, so the practice typically only makes economic sense in dense urban areas.
Rapid Growth
The California Low Carbon Fuel Standard isn't the only policy supporting the RNG industry. Both the federal Renewable Fuel Standard and the recent Inflation Reduction Act also provide subsidies. And other cities, such as New York, are piloting special food waste collections and anaerobic digesters.
With the help of these government subsidies, both clean energy companies and the oil and gas industry are betting big on renewable gas. Back in 2011, eight companies and unions banded together to form the Coalition for Renewable Natural Gas, based in Sacramento, California. The group has now grown to 380 members, including universities, investors, and RNG developers, and major deals are being made. In December 2022, for instance, BP spent $4.1 billon buying RNG producer Archaea Energy. Shell bought Nature Energy in February for nearly $2 billion, and Chevron has formed a joint venture with Brightmark. The Coalition for Renewable Gas reports that 281 RNG facilities are in operation now in the United States, with another 180 under construction and 296 more being planned, up from just 5 n 2002. The Coalition also predicts that the renewable gas market will jump 7-fold (over 2020 levels) by 2030 and 27-fold by 2050 (5).
Phasing out fossil gas would leave oil and gas companies with massive stranded assets, so "renewable natural gas is very appealing," explains Tristan Brown, director of the Bioeconomy Development Institute at SUNY College of Environmental Science and Forestry in Syracuse, New York. "It is a drop-in fuel, so they can re-use the existing infrastructure."
Such policies and investments are good for the climate, some researchers argue. "They are doing more than anything else we've done to reduce biomethane emissions," Brown says.
Yet, at the same time, the incentives for RNG raise a deep, high-stakes question about the best path forward for fighting climate change: whether (and for how long) we should continue to use gas at all, "renewable" or not. "The central debate is: Do we want to invest in maintaining the polluting gas system we have now, or do we want to fundamentally move off of combustion sources?" says Stephan Edel, coalition coordinator of NY Renews, a coalition of more 350 environmental, justice, faith, labor, and community-based organizations.
Faux Solution
Many scientists and environmentalists worry that widespread use of biomethane is misguided. The first issue is that the supply of RNG will always be limited. In some countries where per capita consumption of natural gas is much lower than in the United States, biomethane has greater potential as a replacement fuel. In the United Kingdom, for example, a recent study from the Green Britain Foundation shows that biomethane could compensate for 72% of natural gas consumption by using grass as a gas feedstock, according to coauthor Semra Bakkaloglu, an environmental and chemical engineer at Imperial College London (6).
That's not the case in the United States. Even if it were possible to harness all of the country's food waste, landfills, manure ponds, wastewater treatment plants, and perhaps even some energy crops for gas, the resulting biofuel could replace only a fraction of current natural gas consumption, with most estimates clustering around 10 to 15 percent. "There's not nearly enough renewable natural gas," says Mary Nichols, who chaired the California Air Resources Board from 2007 to 2020, when it developed and implemented the state's Low Carbon Fuel Standard and other climate policies. And although synthetic renewable gas theoretically can be made by adding carbon to hydrogen produced from renewably generated electricity, the economic and practical hurdles of doing so are immense.
A second problem is that producing and using biogas may not be as clean and as climate friendly as its proponents claim. Just like fossil gas, it causes air pollution when burned. More important, emissions can occur at each step of the production process, from the landfill or anaerobic digester to the upgrading facility and the transport pipelines. Plus, the stuff left behind in the digesters-called the digestate-can continue to release gas after being taken out. "It doesn't take much of the methane to slip through to be a significant contributor to planetary warming," warns Cornell's Howarth.
Worrying Emissions
In fact, when Bakkaloglu measured methane emissions at or near renewable gas plants in the United Kingdom, "almost every facility we visited was emitting methane, which is worrying," she says. Overall, she found, methane emissions were more than two times higher than previously estimated, though she notes that with better monitoring and operational practices, those emissions could be significantly reduced (7).
In addition, making RNG is costly. "Anaerobic digesters could be more expensive than the value we get from stopping those methane emissions," says UC Davis' Smith. He calculated that in 2021, it cost $294 to get $68 worth of gas from cow manure (1), starkly illustrating how dependent the entire renewable gas enterprise is on government subsidies. In fact, the pace of investment in renewable gas has slowed over the past year, following a drop in the value of the California credits to only about $60 per metric ton of CO2-equivalent, down from the peak of $200.
Smith and others argue that there may be cheaper and better ways to reduce methane emissions than making RNG and injecting into pipelines. Most of the emissions from milk and beef production-as much as 80%, Howarth says-belch out from the cows themselves; those emissions can be cut by 50% or more with feed additives that inhibit methane production or modify the fermentation process in cows' guts (8). Manure could also be handled differently, Smith suggests. It could be dried and spread on fields or digested by worms, avoiding anaerobic conditions and, thus, methane emissions.
Small Role
These problems don't mean that RNG should be shunned entirely. On the contrary, the consensus among scientists and environmentalists is to collect as much biogas as possible from dairy farms, landfills, wastewater treatment plants, and other sources to cut methane emissions. But these sources should aim to use it on-site or close by, such as in co-located industries. And, perhaps even better, use it in fuel cells, which use electrochemical reactions to generate electricity, to avoid local air pollution from burning the gas. "We argue that's the best use," Howarth says. In such a scenario, biogas and RNG gas could play small, yet meaningful, roles in the global decarbonization effort.
But the debate over RNG is part of a larger policy fight over conventional natural gas, which includes the controversial idea of banning natural gas in new buildings to accelerate a transition to electric power. In 2019, Berkeley, California, was the first city to issue such a ban, against fierce opposition from the gas industry. That prohibition was tossed out by a federal court in April, but dozens of other municipalities, including New York City, San Francisco, San Jose, and Seattle, have followed suit, and in May, New York passed the first state ban. Such regulations could slow or reduce the use of natural gas, renewable or otherwise.
Meanwhile, there's a move by some environmentalists and journalists to drop the term "natural gas" in favor of more the more accurate "methane" or "methane gas," which are viewed less favorably by the public, a recent study shows (9). "Natural gas," they argue, is an industry-concocted term that makes methane seem less dangerous than it is.
Whatever the policies, experts like Nichols, now professor in residence at the Law School of the University of California, Los Angeles, argue that although RNG can play a role in greenhouse gas mitigation-particularly as a fuel or feedstock for industrial processes that are hard to electrify-ending the era of widespread use of natural gas remains a crucial milestone on the path to a lower-carbon world.
John Carey wrote this article for the Proceedings of the National Academy of Science.
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By Jessica Scott-Reid for Sentient.
Broadcast version by Edwin J. Viera for New York News Connection reporting for the Sentient-Public News Service Collaboration
As the calendar flips to a new year, media outlets are once again publishing their annual advice for eating healthier and living better. This year, health reporters continue to be obsessed with the problem of ultra-processed food. And while we are happy to see journalists include research-backed guidance in their coverage, on the whole, our health news feed seems to be missing some vital information.
This year’s crop of healthy eating stories seems to be getting some things right — limiting ultra-processed foods and adding more plants to your diet among them — but journalists and editors continue to miss opportunities to report on health from a broader perspective, one that includes the climate impacts of meat.
Matthew Hayek, assistant professor in the Department of Environmental Studies at New York University, tells Sentient that there’s a general lack of awareness among both the public and the media “about how many resources meat and dairy production really requires,” and “that awareness could really benefit a lot of coverage of this issue.”
Hayek believes there is concern among reporters that “discussing sustainability and diet can feel like piling on to what is already a very fraught, personal and cultural issue.” However, Hayek adds, “what’s really infrequently discussed is that healthy diets and sustainable diets are largely the same thing.”
Trend #1: A Focus on Ultra-Processed Foods
One of the most popular reported topics related to healthy eating in 2025 is undoubtedly ultra-processed foods. Questions about which foods actually qualify as ultra-processed, and how much of them we should and should not be eating, continue to pique reader interest. But while there is a growing body of research raising concerns about ultra-processed foods, not all media coverage is providing readers with a clear picture of the science.
The Washington Post and the New York Times both took on the topic of ultra-processed foods in their New Year’s resolution coverage this year, with the New York Times’ “The Well Challenge: 5 Days to Happier, Healthier Eating” kicking off an entire series on ultra-processed foods. “We’re not just paying attention to the nutrients in our food,” the article reads. “We’re also looking for clues to tell whether a food was processed — and if so, how much.”
What we know: a growing body of studies suggests ultra-processed food consumption might be linked to an increased risk of a host of health problems, including obesity, heart disease and cancer. These foods, which make up more than half of the calories consumed at home in the U.S., are optimized to bypass our body’s natural satiety cues, which can lead to eating more than you intended.
But researchers do not agree on, nor do they know for sure, what it is about ultra-processed food that is the culprit. In fact, there is still fierce debate over the category itself. As the Washington Post reports, “not all ultra-processed foods are created equal.” The Post’s story on “healthier processed foods” explains that some foods deemed ultra-processed by some researchers, such as sliced bread and peanut butter, can be part of a healthy diet.
Kevin Hall, nutrition and metabolism researcher at the National Institutes of Health, said this to the New York Times: “Not all ultra-processed foods are necessarily bad for you,” and not all unprocessed foods are good for you, either. “Just because Grandma made it, doesn’t make it healthy.”
For Teresa Fung, professor of nutrition and dietetics at Simmons University, and adjunct professor at Harvard University’s T.H. Chan School of Public Health, whether a food is ultra-processed matters less to her than what it’s made of. “It really depends on what the food is,” she told Sentient. “The things I would rather look at are the ingredients list, as well as the nutrient content.”
Not only does coverage of this topic tend to confuse people about what’s good for their own health, but the lack of clarity can have major consequences for climate action. The reporting often overlooks or even discourages the very shift that climate experts are encouraging in the global north to reduce environmental impact: plant-based diets.
Case in point: media coverage positioning plant-meats as ultra-processed and unhealthy. This narrative emerged a few years back, with some links to the meat industry emerging even, and continues to this day.
For example, a Lancet study published in 2024, examining how ultra-processed foods affect heart health and mortality risk, led to outlets including the Daily Mail, New York Post and People magazine linking (incorrectly) plant-based foods to increased heart disease risk. In that study, plant-based meats made up only 0.5 percent of participants’ diets, among other “plant-based” ultra-processed foods like biscuits and soda.
More recently (and more accurately), the New York Times summed up the issue of plant-based meats being roped into the processed foods narrative as follows: “If plant based meat must be categorized as processed food, the argument is that they are more like canned beans than Twinkies, and a long way from processed meats, the category that includes hot dogs, bacon and deli meat, which the World Health Organization has classified as carcinogenic to humans.”
However, this broader take on ultra-processed food was part of The New York Times’ climate coverage, not its New Year’s Resolution health coverage; another example of how climate coverage is often siloed from the rest of the newsroom, leading to conflicting information from story to story.
Trend #2: Still Ignoring Planetary Health
One diet often touted by the media as one of the healthiest is the Mediterranean Diet. This diet, according to CNN’s “2025 best diet wins gold for wellness and disease prevention,” focuses on fruits, vegetables, grains, olive oil and nuts, with limited dairy, meat and sweets.
CNN and others get the personal health angle here right. According to Harvard School of Public Health, “research has consistently shown that the Mediterranean diet is effective in reducing the risk of cardiovascular diseases and overall mortality.” But once again, the news coverage tends to leave climate and other environmental concerns out of the discussion of what constitutes healthy food choices, by encouraging a shift to fish from meat without mentioning any of the tradeoffs.
As climate change grows worse, fish will become harder to count on as a food source. According to one paper on the Mediterranean diet, published in the American Heart Journal Plus, which touches on this concern, “rising sea levels and ocean temperatures can disrupt marine ecosystems, affecting fish populations.”
The practice of overfishing also creates serious climate impacts. Oceans can absorb around 31 percent of carbon dioxide emissions and store 60 times more carbon than the atmosphere, with billions of sea creatures, from sardines to whales, sustaining this cycle. As Heidi Pearson, a marine biology professor at University of Alaska Southeast, told Sentient in 2024, “The more fish we take out of the ocean, the less carbon sequestration we are going to have.” According to rough calculations by Sentient, ending the practice of overfishing would store the same amount of carbon as 6.5 million acres of forest each year.
One of the most highly consumed fish, salmon, comes with a host of environmental and ethical issues. An estimated 70 percent of the world’s salmon now comes from fish farms, where crowded conditions promote disease spread, leading to increased antibiotic use and resistance in humans. Escaped farmed salmon can also threaten wild fish populations, and aquaculture waste can pollute surrounding ecosystems. Yet in most healthy eating coverage, you rarely hear more about salmon beyond the fact that it is a healthy source of omegas.
In its “10 Tips to Help You Eat Healthier in 2025,” The New York Times does a little better by mentioning the environmental impact of seafood. It highlights bivalves — clams, oysters, mussels, and scallops — as more sustainable sources of protein, “without the environmental baggage of many other seafood options.”
Worth pointing out, however, that not every researcher agrees. Ecologist Spencer Roberts tells Sentient via email, while bivalve farms may have some environmental benefits, they are “a sad substitute for an oyster reef,” and reintroducing bivalves in restoration projects offers more ecological value than aquaculture operations.
Trend #3: Plant-Based Eating Is in, Fully Plant-Based Diet? Not So Much
With all the talk of health and wellness in the New Year, it’s inevitable that newer diet fads dominate the news. In Newsweek’s coverage of “Food Trends to Embrace in 2025, According to Scientists,” the outlet tackles hot topics like gut health, intermittent fasting, and of course, ultra-processed foods. It also takes on the social media-hyped carnivore diet — eating almost exclusively meat and other animal products — in comparison to a plant-based diet.
First, let’s talk about what Newsweek’s expert, professor and author Tim Spector, gets right. He does not recommend the carnivore diet, which lines up with what most registered dietitians have to say. He also told Newsweek, “You don’t need to become vegan, but adding more vegetables, legumes, nuts and seeds, whole fruits and whole grains while reducing red and processed meats is a winning strategy.” He’s not entirely wrong, especially when it comes to personal health. Eating more plants, and less meat, is both good for you, and it’s also good for the planet. But does continuing to position “vegan” as extreme (like the carnivore diet) give readers useful and accurate information?
In much of the current mainstream news coverage on healthy eating in the New Year, this appears to be a common theme: focusing on plant-heavy diets, without suggesting people eat plant-exclusive. Whether it’s the Mediterranean diet, DASH diet (or the MIND diet, which combines the two), Flexitatianism or Reducetarianism, mindfully eating less meat and more plants continues to be an evolving trend.
Presumably Newsweek wants its readers to know that eating habits don’t have to be all or nothing. If a vegan diet seems too challenging, eating less is certainly progress from decades past. (We’ve made similar points here at Sentient, too.) But people care about climate action and they also care about animal welfare, according to polling research. What to eat is an individual choice, but these choices have impacts, and good journalism has an obligation to include that information.
Eating a vegan diet has well-documented environmental benefits, even at the individual level, including cutting one’s climate emissions by about 75 percent, and water usage by over half. At the global level, a shift to a plant-based food system would reduce global agricultural land use by an estimated 75 percent, freeing up those spaces for the kind of crucial rewilding that can help offset emissions.
As the accelerating effects of climate change are becoming more and more visible, perhaps 2026 New Year’s Resolution coverage will see mainstream media make the connection between planetary health and personal diets — trending or not. “There’s a lot of room for win-wins here,” says Hayek, as “diets that are more healthy are more sustainable, and vice versa.” He suggests that journalists reporting on healthy eating seek out environmental scientists, like himself, to get the bigger picture.
Jessica Scott-Reid wrote this article for Sentient Climate.
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By Seth Millstein for Sentient.
Broadcast version by Mark Richardson for Ohio News Connection reporting for the Sentient-Public News Service Collaboration
In an unexpected but no-less-depressing development, NASA has announced that 2024 was the hottest year on record. This wasn’t an anomaly, as every one of the past 10 years has been one of the 10 hottest years in the planet’s history. Climate change is a serious problem in need of a serious solution — but what counts as a viable climate solution, and what doesn’t?
It’s not an easy question to answer. In fact, you might even say it doesn’t have an answer, at least not a single one. While there is certainly widespread agreement about the need to decarbonize, there is also an ongoing debate among climate scientists about which solutions to prioritize and when. That debate is important, as there’s no single “silver bullet” for bringing down global temperatures, so we have to have these difficult conversations.
“This is pretty hard, right?,” University of Hawaii Oceanography Professor David Ho tells Sentient. “If we’re talking about carbon dioxide removal, basically, you’re talking about the largest thing that humanity has ever done.”
This illustrates the enormity of the task at hand. It’s the “largest thing humanity has ever done” — and Ho isn’t even talking about reducing our emissions across the board. He’s merely talking about carbon dioxide removal, which as we’ll see, is just one element.
Although there’s disagreement around how best to fight climate change, the contours of these disagreements are illuminating, because they’re often about deeper divides and tough decisions.
Climate Solutions, Defined
First, let’s talk about basic definitions. When we talk about climate change, we’re usually talking about rising global temperatures. Greenhouse gases — primarily carbon dioxide, methane and nitrous oxide — are the main reason temperatures are rising.
That’s why Amanda Smith, senior scientist at the climate organization Project Drawdown, argued in a 2024 webinar that any climate change solution must, by definition, reduce the concentration of greenhouse gases in the atmosphere.
This can be accomplished in two ways: by reducing the amount of carbon dioxide we emit in the first place, and by trapping and storing carbon dioxide that’s already been emitted. The first approach is commonly referred to as decarbonization, while the second is known as either carbon capture or carbon removal, depending on the method used.
How to Prioritize the Best Climate Solutions
Here’s where things get trickier. Although many burgeoning climate technologies and innovations have potential, Smith argues that only the ones that can effectively be deployed now can truly be considered solutions. High costs, logistical burdens, legal hurdles and other obstacles mean that many potential solutions aren’t yet ready for prime time.
Smith also argues that a climate solution isn’t much of a solution if it simply offloads carbon emissions to another sector — or causes other environmental damage that isn’t strictly emissions-related, like freshwater pollution. Or, if you advocate for better treatment of farm animals, you might argue that just switching from beef to chicken isn’t a great solution either, because it increases suffering for billions of chickens.
Humanity is facing some tough choices, Ho says. In his opinion, it’s not necessarily a dealbreaker for a climate solution to cause some collateral damage to the environment, so long as the net environmental impact is positive. Climate change will eventually render our planet unlivable if left unchecked, and so we can’t afford to reject effective solutions just because they have negative side effects that, in the grand scheme of things, are less consequential than the consequences of doing nothing.
“It’s the whole trolley problem thing,” Ho says, referring to the philosophical thought experiment that poses a quandary about whether it’s worth diverting a trolley to save five people at the expense of one. “Climate change is going to affect a lot of organisms. If we deploy a solution and it negatively affects, you know, one whale, versus if climate change kills 10 whales, which one do we choose?”
What Factory Farming Has to Do With Climate Change
Climate research suggests there is no way to stave off the worst of global warming without addressing food-related emissions. Our global food system is responsible for around a third of all greenhouse gas emissions, and most of that third is fueled by the meat we eat, especially from cows.
The vast majority of meat comes from factory farms. But to be clear, all kinds of meat production, whether industrial or small-scale, have a negative impact on the environment. Even so-called extensive farming operations, like regenerative or organic, that tout better treatment of animals and reduced use of synthetic chemicals, exact an unavoidable climate cost in the form of enormous land usage — at least, if we’re talking about beef.
Why Beef Production in Particular Has to Be Addressed
Although all types of meat production pollute the environment to some degree, beef is responsible for the largest climate impact, and there are two big reasons why.
Deforestation
First, there’s the removal of trees (and other uncultivated landscapes like peat bogs) that are staving off the impacts of climate change. Agricultural expansion is the culprit behind 90 percent of deforestation, and beef farming in particular is the leading driver of deforestation worldwide.
When trees are removed and peat bogs are drained, the carbon dioxide that’s so helpfully trapped there is released back into the atmosphere. Worse than that, we also miss out on the climate protection these landscapes would have provided for well into the future, something scientists call the “carbon opportunity cost.”
Methane From Cattle Burps and Farm Animal Waste
The biology of the cows themselves is the other factor here, as they are a huge contributor to factory farms’ climate pollution. Cows’ burps, farts and waste all emit methane, one of the most potent greenhouse gasses there is, and so cattle ranches and dairy farms continually release massive amounts of greenhouse gases into the air on a daily basis.
On a more positive note, the flip side of this is also true. Tackling methane emissions, whether by fixing gas leaks or eating less meat, is an opportunity to curb climate pollution quickly.
4 Potential Climate Solutions, and Their Viability
There is plenty of agreement about many of the broad strokes of climate action — curbing dependence on fossil fuels, the need to electrify the grid and even the benefit of plant-forward sustainable diets, for instance. Yet there is also debate about what the path to a better future should look like.
Some favor modest changes to existing systems, whereas others insist on full-scale reform, or even abolition, of those systems. Some focus squarely on one high-emissions sector — for instance, agriculture or fossil fuels — while others support what Smith calls a “tapestry” of solutions across many industries. There are also fierce debates about the role of technology, whether the solution is cultivated meat, nuclear energy or carbon storage pipelines.
Let’s take a look at the debates over a few proposed climate solutions, as each illuminates a deeper philosophical divide.
1. Decarbonization & Carbon Removal
As mentioned earlier, there are two ways to bring down the concentration of CO2 in the atmosphere: reducing emissions at the source, or removing CO2 that’s already been emitted. Both approaches are necessary if we want to eventually reach net-zero carbon emissions, because some emissions — such as those from airplanes — will never be eliminated entirely.
A lot of companies have invested heavily in technology that removes carbon dioxide from the air. That’s one of the upsides to carbon removal as a strategy: it has a lot of buy-in and money behind it, including from major polluters like Exxon. This is largely because it doesn’t require them to actually reduce their carbon emissions.
Carbon Capture Is Slow and Costly
The various methods we have for trapping carbon from the atmosphere don’t do so nearly fast enough to compensate for the amount of carbon we emit on a daily basis. It’s like using a teaspoon to empty out a boat that’s rapidly filling up with water: it won’t work.
For this reason, Ho argues, we first need to dramatically reduce how much carbon we emit before deploying technology to remove it from the air.
“It will always cost more energy to do the removal than to not emit it in the first place,” Ho tells Sentient. “So we really should concentrate our energy on decarbonization, and not putting the CO2 into the atmosphere [in the first place].”
2. Digesters
Digesters are essentially large, oxygen-free containers that take organic waste, like animal manure, and turn it into something else, kind of. The digester, or reactor, contains microbial communities that are specifically designed to break down the manure and convert its emissions into biofuel. This fuel can then be used by cars and other vehicles.
The dairy industry has been a particularly vocal proponent of digesters, which received millions in funding from the Biden administration through the Inflation Reduction Act. Much like carbon removal technology, digesters have buy-in from polluting industries like pork, dairy, oil and gas, and don’t require any large-scale change to how these industries function.
But in practice, digesters come with plenty of downsides that cast doubt on their efficacy.
Digesters Are Expensive and Seem to Entrench Factory Farming
To begin with, the biofuels digesters create are still a form of gas. They still emit carbon when they’re burned. As such, many environmentalists argue that producing them perpetuates our reliance on gas-powered vehicles, and forestalls a transition to zero-emission electric vehicles, and away from factory farms.
Due to their expense, digesters are only practical for use on the largest factory farms, and they rely on the continued use of manure lagoons, which have a host of negative environmental and social impacts themselves.
Rebecca Wolf, a senior food policy analyst at the nonprofit Food & Water Watch, argues against digesters and biofuels on the grounds that they allow the factory farm system itself to continue chugging along without meaningful reform, while continuing to emit significant amounts of greenhouse gasses.
“They require factory farms to continue to produce large amounts of waste,” Wolf tells Sentient. “And so they’re perfect to put on top of a factory farm, and then keep that waste stream going.”
Digesters, Wolf says, “bring together Big Oil and Big Ag,” as they allow both industries to “greenwash their waste products” while continuing to emit prolific amounts of greenhouse gases.
3. Feed Additives
Feed additives are similar to digesters in that they’re designed to reduce methane emissions on animal farms. But while digesters do this by capturing methane that’s emitted from animal waste, feed additives reduce the amount of methane animals emit in the first place by altering the way their bodies digest food.
Although most feed additives haven’t yet been subject to rigorous testing, one exception is a compound known as 3-NOP. Studies of 3-NOP suggest that it could reduce enteric methane emissions by as much as 32.5 percent.
Feed Additives Aren’t So Practical or Effective
In order to work, animals need to eat feed additives every day; this works for cattle who are fed concentrates, but for those that feed via grazing, ensuring that each of them eat enough additives every day is a logistical nightmare.
Moreover, these additives aren’t cheap. While fighting climate change benefits all of humanity in the long run, buying expensive feed additives doesn’t benefit individual farmers in the short run; it hurts their bottom line, and this is a major obstacle to the widespread adoption of feed additives.
Lastly, because most feed additives haven’t yet been sufficiently studied, it’s unclear what other effects they might have on animals or humans. There’s even some research that 3-NOP, ostensibly one of the most promising feed additives, actually increases carbon dioxide emissions.
“Animal agriculture has a lot of negative environmental impacts,” Ho tells Sentient. “It’s not just the CO2 emissions. If you feed some seaweed to cows, you’re still going to get the other negative environmental impacts. Those aren’t going away, and so it does seem like we should do something that will reduce all of those impacts, not just the CO2 or the methane.”
4. Reducing Meat Consumption
There’s an elephant in the room when we talk about animal agriculture as a driver of climate change: our appetite for animal products. Per-capita meat and dairy consumption have been steadily rising over the decades, and with it, our reliance on factory farms as a food source. Climate “solutions” like feed additives and digesters do nothing to stem this appetite. In fact, they seem to help entrench our current food system even further.
Many climate research groups, like World Resources Institute and Project Drawdown, have pointed out that if global north countries simply ate less meat, especially beef, this would make a huge dent in the climate problem. In practical terms, such a reduction would have to take place primarily in middle- and upper-income countries, which consume a disproportionate amount of meat on a per-capita basis.
“The choice of what people eat matters a lot,” Ho says. “If we stop eating beef and cut down on dairy, or just cut out dairy altogether, that would make a huge difference.”
Cultivated Meat Could Help With Meat Reduction
Ho is optimistic about cultivated meat as a potential climate solution. The prospect of being able to create real meat in a laboratory without needing to clear away land, house, feed and slaughter millions of animals is an incredibly appealing proposition in the fight to bring down carbon emissions and reduce global temperatures.
Cultivated meat technology is still in its infancy, though. As it stands, it’s still much too expensive to scale; this means it can’t be deployed now, which means it doesn’t yet meet Smith’s criteria for a climate solution.
Just as significantly, cultivated meat — and any climate solution that entails people replacing traditional meat in their diet — faces cultural hurdles. Many people, including some powerful elected officials, are skeptical of meat that’s created in a laboratory, and in the U.S., some Republican governors have even signed laws banning its sale within their states.
But Ho is supportive of the technology, which may well become more affordable and practical as future research brings down its production costs.
“I know that some people are not really into cultivated meat, but I would get more excited about that than like, reducing methane emissions from cows,” Ho tells Sentient. “It also deals with the animal suffering part of it, which I think is huge.”
The Bottom Line
There are contentious debates happening around climate action — how much should we invest in technologies, versus fundamentally remaking the way we produce things — especially food. There are deep divides, yet there is also a lot of agreement on simpler strategies, like eating less meat and more beans; a diet that remains healthier for the planet and its inhabitants, animals and people alike.
Seth Millstein wrote this article for Sentient.
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Electric vehicles in North Carolina and around the country are getting love this week.
A coalition of clean vehicle advocates has declared the week leading up to Valentine's Day EV Love Story week.
The week comes in the midst of the Trump administration's suspension of a $5 billion electric vehicle charging station program.
But that hasn't put a damper on the experience of electric vehicle driver Gene Kelly, who is the energy specialist for Rockingham County Schools in North Carolina.
"Do I want to use the fuel in my other vehicle that I have to pay three to four times more for," said Kelly, "or should I just take my electric vehicle and conserve the fuel in my gas vehicle? It's a no-brainer decision."
More than 81,000 electric vehicles were registered in North Carolina as of September 2024, according to state Department of Transportation data.
In 2022, former Gov. Roy Cooper set a goal of having 1.25 million zero-emission vehicles on the road by 2030.
Kelly said there are many advantages to electric vehicles, including technology that makes them safer.
"Safety and I'm improving the environment of the community that I live in," said Kelly, "because that's where I use my energy."
Even if there are policy shifts on the federal level under President Trump, Kelly said car manufacturers are diving into electric vehicles.
"They've already left the starting line and so there are a lot of options," said Kelly, "and I think that with more options the American consumer can feel very comfortable making a decision to move to electric vehicles."
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