When Rattan Lal was awarded the Japan Prize for Biological Production, Ecology in April—the Asian equivalent of a Nobel—the audience at Tokyo's National Theatre included the emperor and empress. Lal's acceptance speech, however, was down-to-earth in the most literal sense.
Carbon, in its proper place, holds landscapes and ecosystems together.
"I'd like to begin, rather unconventionally, with the conclusion of my presentation," he told the assembled dignitaries. "And the conclusion is four words: In soil we trust."
That statement could serve as the motto for a climate crisis-fighting strategy that has gained remarkable momentum over the past five years or so—and whose rise to international prominence was reflected in that glittering award ceremony. Lal, a septuagenarian professor of soil science at Ohio State University, is one of the foremost exponents of carbon farming, an approach that centers on correcting a man-made, planetary chemical imbalance.
A Solution to Several Problems at Once?
The chemical in question is carbon. Too much of it in the atmosphere (in the form of carbon dioxide, a potent greenhouse gas) is the main driver of global heating. Too little of it in the soil is the bane of farmers in many parts of the world, and a threat to our ability to feed a ballooning global population. Advocates say agriculture can mitigate both problems—by adopting techniques that keep more soil carbon from escaping skyward, and draw more atmospheric carbon down into fields and pastures.
The potential impacts go beyond slowing climate change and boosting food production. "There are so many benefits," says Lal. "Water quality, drought, flooding, biodiversity—this is a natural solution for all these problems." That's because carbon, in its proper place, holds landscapes and ecosystems together. Plants extract it from the air and convert it into sugars for energy; they also transfer it to the soil through their roots and in the process of decomposition. In the ground, carbon feeds microbes and fungi that form the basis of complex food webs. It helps soil absorb and retain water, resist erosion, and hold onto nitrogen and phosphorous—keeping those nutrients from running off into waterways and creating toxic algal blooms.
Government and private support for research into carbon-conscious agriculture is on the rise, and growing numbers of farmers are exploring such methods. How much difference these methods can make, however, remains a matter of debate. Lal sees carbon farming as a way to buy time until CO2 emissions can be brought under control. Skeptics insist that such projections are overly optimistic. Some allies, meanwhile, think Lal's vision is too timid. "Farming can actually fix the climate," says Tim LaSalle, co-founder of the Center for Regenerative Agriculture at California State University, Chico. "That should be our only focus."
Yet Can soil solve the climate crisis? may be not be the key question in assessing the promise of carbon farming, since it implies that action is worthwhile only if a solution is ensured. A more urgent line of inquiry might be: Can the climate crisis be solved without addressing soil?
A Chance Meeting Leads to the Mission of a Lifetime
Lal was among the earliest scientists to grapple with that question. Born in Pakistan, he grew up on a tiny subsistence farm in India, where his family had fled as refugees. The only one of his siblings who learned to read and write, he attended a local agricultural university, then headed to Ohio State on scholarship for his PhD. In 1982, he was working at the International Institute of Tropical Agriculture in Nigeria, trying to develop sustainable alternatives to Africa's traditional slash-and-burn farming, when a distinguished visitor dropped by: oceanographer Roger Revelle, who 25 years earlier had published the first paper warning that fossil fuel combustion could throw the climate dangerously off-kilter.
Rattan Lal, Distinguished University Professor of Soil Science at Ohio State, received the Japan Prize at a ceremony in April.
(Photo: Ken Chamberlain. CFAES.)
Lal showed Revelle the soil in his test plots—hard and reddish, like much of Africa's agricultural land. Then (as described in Kristin Ohlson's book The Soil Will Save Us), he led the visitor to the nearby forest, where the soil was dark, soft, and wriggling with earthworms. In the forest, the soil's carbon content was 2 to 3 percent; in Lal's plots, it had dwindled to 0.5 percent. When Revelle asked him where all that carbon had gone, Lal confessed he didn't know. Revelle suggested that much of it might have floated into the atmosphere, adding to the burden of greenhouse gases. "Since then," Lal told me, "I've been looking for ways to put it back."
Back at Ohio State, Lal found that the United States Department of Agriculture (USDA) and Environmental Protection Agency (EPA) were also interested in the connection between soil carbon and climate change. With a small group of other scientists, he began investigating the dimensions of the problem, and how it might be solved.
Comparing carbon in forested and cultivated soils around the globe, the researchers calculated that about 100 billion tons had vanished into the air since the dawn of agriculture 10,000 years ago. The culprits were common practices—including plowing, overgrazing, and keeping fallow fields bare—that exposed soil carbon to oxygen, transforming it into carbon dioxide. Yet the process could also be reversed, Lal and his colleagues argued. Although there was a limit to the amount of carbon that soil could hold, they theorized that it would be possible to sequester several billion tons of global CO2 emissions each year for decades before reaching maximum capacity.
Lal set up projects on five continents to explore practices that could help accomplish that goal, such as minimizing tillage, planting cover crops, and leaving residue on fields after harvest. He organized conferences, pumped out papers and books. As other researchers launched similar efforts, policymakers worldwide took notice.
But before long, recalls Colorado State University soil scientist Keith Paustian (a fellow carbon-farming pioneer, who served with Lal on the UN's International Panel on Climate Change), official attention "kind of faded away. The bigger imperative was to cut emissions." And because agriculture accounted for only about 13 percent of greenhouse gas pollution, Paustian says, the sectors that emitted the most—energy and transportation—got the bulk of funding.
A Movement on the Rise
In recent years, however, carbon farming has begun to look like an idea whose time has come. One factor is that efforts to reduce emissions haven't worked; in 2018 alone, global CO2 output rose by an estimated 2.7 percent, according to the Global Carbon Project. Last month, researchers from the Scripps Institute of Oceanography reported that atmospheric CO2—under 350 ppm when Lal began his quest—had reached 415 ppm, the highest in 3 million years. And with the world's population expected to approach 10 billion by 2050, the need for sustainable technologies to augment food production has grown increasingly pressing.
Today, carbon-conscious methods are central to the burgeoning movement known as "regenerative agriculture," which also embraces other practices aimed at improving soil health and farming in an ecologically sound (though not always strictly organic) manner. In the United States, the latest Farm Bill includes $25 million to incentivize soil-based carbon sequestration. State and local governments across the country are supporting such efforts, as are at least a dozen nonprofits. The Department of Energy's Advanced Projects Research Agency (ARPA-e) is working to develop crops and technologies aimed at increasing soil carbon accumulation by 50 percent. General Mills recently announced plans to advance regenerative farming on 1 million acres by 2030, and many smaller companies have made their own commitments.
The toughest challenge, Lal suggests, may be persuading farmers to change their ways.
Internationally, the biggest initiative is the French-led "4 per 1,000" initiative, which aims to increase the amount of carbon in the soil of farms and rangelands worldwide by 0.4 percent per year—a rate that the project's website contends would "halt the increase of CO2 (carbon dioxide) concentration in the atmosphere related to human activities."
Given the current pace of research, Lal believes that goal—which equates to sequestering 3.6 billion tons of CO2 annually, or 10 percent of global emissions—is doable. The toughest challenge, he suggests, may be persuading farmers to change their ways. Although carbon farming can reduce costs for chemical inputs such as herbicides and fertilizers, while building rich topsoil, agriculturalists tend to be a conservative lot.
And getting low-income farmers to leave crop residue on fields, instead of using it for fuel or animal feed, will require more than speeches about melting glaciers. Lal proposes a $16 per acre subsidy, totaling $64 billion for the world's 4 billion acres of cropland. "That's not a very large amount," he says, "if you're investing in the health of the planet."
Experimental Methods Attract Supporters and Skeptics
Some experts question whether enough CO2 can be stashed in the soil to prevent the rise in average global temperature from surpassing the 2º C mark—set by the 2016 Paris Agreement as the limit beyond which climate change would become catastrophic. But others insist that carbon farming's goal should be to reverse climate change, not just to put it on pause.
"That's the only way out of this predicament," says Tim LaSalle, whose Center for Regenerative Agriculture supports the use of experimental methods ranging from multi-species cover cropping to fungal-dominant compost solutions. Using such techniques, a few researchers and farmers claim to be able to transfer carbon to the soil at rates many times higher than with established practices. Although several of these methods have yet to be documented in peer-reviewed studies, LaSalle believes they point the way forward. "We can't fix the climate, or even come close to it, using Rattan's numbers," he says, referring to Lal. "If we can replicate these experiments, we can fix it."
Even scientists sympathetic to regenerative ag warn that relying on unproven techniques is risky. "Some of these claims are beyond anything we've seen in agricultural science," says Andrew McGuire, an agronomist at Washington State University. "They could be right, but extraordinary claims require extraordinary evidence."
Still, the assorted methods currently being tested—which also include amending soil with biochar (made by heating agricultural wastes with minimal oxygen), planting long-rooted perennial crops instead of short-rooted annuals, and deploying grazing animals in ways that enrich soil rather than depleting it—offer a catalogue of hope at a time when environmental despair is all too tempting.
Last October, the National Academy of Sciences, Engineering, and Medicine issued a report acknowledging that it was too late to stave off apocalyptic overheating just by reducing CO2 emissions; removing carbon from the atmosphere would be necessary as well. The document laid out several options for doing so—most of which, it cautioned, had serious limitations.
"Soil is a bridge to the future. We can't do without it."
One possibility was planting more forests. To absorb enough carbon dioxide, however, trees might have to replace areas of farmland, reducing the food supply. Another option was creating biomass plantations to fuel power plants, whose emissions would be stored underground. But land use would be a problem: "You'd need to cover an area the size of India," explains Paustian, who was a co-author of the report. Yet another alternative was direct-air capture, in which chemical processes would be used to extract CO2 from the air. The technology was still in its infancy, though—and the costs and power requirements would likely be astronomical.
The report took up agriculture-based methods on page 95. Those needed further research as well, the authors wrote, to determine which approaches would be most effective. But of all the alternatives, this one seemed the least problematic. "Soil carbon is probably what you can do first, cheapest, and with the most additional co-benefits," says Paustian. "If we can make progress in that area, it's a huge advantage."
In any case, he and other researchers agree, we have little choice but to try. "Soil is a bridge to the future," Lal says. "We can't do without it."
You are driving along the highway and see an electronic sign that reads: “3,238 traffic deaths this year.” Do you think this reminder of roadside mortality would change how you drive? According to a recent, peer-reviewed study in Science, seeing that sign would make you more likely to crash. That’s ironic, given that the sign’s creators assumed it would make you safer.
The study, led by a pair of economists at the University of Toronto and University of Minnesota, examined seven years of traffic accident data from 880 electric highway sign locations in Texas, which experienced 4,480 fatalities in 2021. For one week of each month, the Texas Department of Transportation posts the latest fatality messages on signs along select traffic corridors as part of a safety campaign. Their logic is simple: Tell people to drive with care by reminding them of the dangers on the road.
But when the researchers looked at the data, they found that the number of crashes increased by 1.52 percent within three miles of these signs when compared with the same locations during the same month in previous years when signs did not show fatality information. That impact is similar to raising the speed limit by four miles or decreasing the number of highway troopers by 10 percent.
The scientists calculated that these messages contributed to 2,600 additional crashes and 16 deaths annually. They also found a social cost, meaning the financial expense borne by society as a whole due to these crashes, of $377 million per year, in Texas alone.
The cause, they argue, is distracted driving. Much like incoming texts or phone calls, these “in-your-face” messages grab your attention and undermine your focus on the road. The signs are particularly distracting and dangerous because, in communicating that many people died doing exactly what you are doing, they cause anxiety. Supporting this hypothesis, the scientists discovered that crashes increase when the signs report higher numbers of deaths. Thus, later in the year, as that total mortality figure goes up, so do the percentage of crashes.
Boomerang effects happen when those with authority, in government or business, fail to pay attention to the science. These leaders rely on armchair psychology and gut intuitions on what should work, rather than measuring what does work.
That change over time is not simply a function of changing weather, the study’s authors observed. They also found that the increase in car crashes is greatest in more complex road segments, which require greater focus to navigate.
The overall findings represent what behavioral scientists like myself call a “boomerang effect,” meaning an intervention that produces consequences opposite to those intended. Unfortunately, these effects are all too common. Between 1998 and 2004, Congress funded the $1 billion National Youth Anti-Drug Media Campaign, which famously boomeranged. Using professional advertising and public relations firms, the campaign bombarded kids aged 9 to 18 with anti-drug messaging, focused on marijuana, on TV, radio, magazines, and websites. A 2008 study funded by the National Institutes of Health found that children and teens saw these ads two to three times per week. However, more exposure to this advertising increased the likelihood that youth used marijuana. Why? Surveys and interviews suggested that young people who saw the ads got the impression that many of their peers used marijuana. As a result, they became more likely to use the drug themselves.
Boomerang effects happen when those with authority, in government or business, fail to pay attention to the science. These leaders rely on armchair psychology and gut intuitions on what should work, rather than measuring what does work.
To be clear, message campaigns—whether on electronic signs or through advertisements—can have a substantial effect on behavior. Extensive research reveals that people can be influenced by “nudges,” which shape the environment to influence their behavior in a predictable manner. For example, a successful campaign to reduce car accidents involved sending smartphone notifications that helped drivers evaluate their performance after each trip. These messages informed drivers of their personal average and best performance, as measured by accelerometers and gyroscopes. The campaign, which ran over 21 months, significantly reduced accident frequency.
Nudges work best when rigorously tested with small-scale experiments that evaluate their impact. Because behavioral scientists are infrequently consulted in creating these policies, some studies suggest that only 62 percent have a statistically significant effect. Other research reveals that up to 15 percent of desired interventions may backfire.
In the case of roadside mortality signage, the data are damning. The new research based on the Texas signs aligns with several past studies. For instance, research has shown that increasing people’s anxiety causes them to drive worse. Another, a Virginia Tech study in a laboratory setting, found that showing drivers fatality messages increased what psychologists call “cognitive load,” or the amount of information your brain is processing, with emotionally-salient information being especially burdensome and preoccupying, thus causing more distraction.
Nonetheless, Texas, along with at least 28 other states, has pursued mortality messaging campaigns since 2012, without testing them effectively. Behavioral science is critical here: when road signs are tested by people without expertise in how minds work, the results are often counterproductive. For example, the Virginia Tech research looked at road signs that used humor, popular culture, sports, and other nontraditional themes with the goal of provoking an emotional response. When they measured how participants responded to these signs, they noticed greater cognitive activation and attention in the brain. Thus, the researchers decided, the signs worked. But a behavioral scientist would note that increased attention likely contributes to the signs’ failure. As the just-published study in Science makes clear, distracting, emotionally-loaded signs are dangerous to drivers.
But there is good news. First, in most cases, it’s very doable to run an effective small-scale study testing an intervention. States could set up a safety campaign with a few electric signs in a diversity of settings and evaluate the impact over three months on driver crashes after seeing the signs. Policymakers could ask researchers to track the data as they run ads for a few months in a variety of nationally representative markets for a few months and assess their effectiveness. They could also ask behavioral scientists whether their proposals are well designed, whether similar policies have been tried previously in other places, and how these policies have worked in practice.
Everyday citizens can write to and call their elected officials to ask them to make this kind of research a priority before embracing an untested safety campaign. More broadly, you can encourage them to avoid relying on armchair psychology and to test their intuitions before deploying initiatives that might place the public under threat.
I walked through the Dong Makkhai forest-products market, just outside of Vientiane, the laid-back capital of the Lao Peoples Democratic Republic or Lao PDR. Piled on rough display tables were varieties of six-legged wildlife–grasshoppers, small white crickets, house crickets, mole crickets, wasps, wasp eggs and larvae, dragonflies, and dung beetles. Some were roasted or fried, but in a few cases, still alive and scrabbling at the bottom of deep plastic bowls. I crunched on some fried crickets and larvae.
One stall offered Giant Asian hornets, both babies and adults. I suppressed my inner squirm and, in the interests of world food security and equity, accepted an offer of the soft, velvety larva; they were smooth on the tongue and of a pleasantly cool, buttery-custard consistency. Because the seller had already given me a free sample, I felt obliged to buy a chunk of the nest with larvae and some dead adults, which the seller mixed with kaffir lime leaves.
The year was 2016 and I was in Lao PDR because Veterinarians without Borders/Vétérinaires sans Frontières-Canada had initiated a project on small-scale cricket farming. The intent was to organize and encourage rural women to grow crickets as a source of supplementary protein and sell them at the market for cash. As a veterinary epidemiologist, I had been trained to exterminate disease spreading insects—Lyme disease-carrying ticks, kissing bugs that carry American Sleeping Sickness and mosquitoes carrying malaria, West Nile and Zika. Now, as part of a global wave promoting insects as a sustainable food source, I was being asked to view arthropods as micro-livestock, and devise management methods to keep them alive and healthy. It was a bit of a mind-bender.
The 21st century wave of entomophagy, or insect eating, first surged in the early 2010s, promoted by a research centre in Wageningen, a university in the Netherlands, conferences organized by the Food and Agriculture Organization of the United Nations, and enthusiastic endorsements by culinary adventurers and celebrities from Europeanized cultures. Headlines announced that two billion people around the world already ate insects, and that if everyone adopted entomophagy we could reduce greenhouse gases, mitigate climate change, and reign in profligate land and water use associated with industrial livestock production.
Furthermore, eating insects was better for human health than eating beef. If we were going to feed the estimated nine billion people with whom we will share the earth in 2050, we would need to make some radical changes in our agriculture and food systems. As one author proclaimed, entomophagy presented us with a last great chance to save the planet.
In 2010, in Kunming, a friend had served me deep-fried bamboo worms. I ate them to be polite. They tasted like French fries, but with heads.
The more recent data suggests that the number of people who eat insects in various forms, though sizeable, may be closer to several hundreds of millions. I knew that from several decades of international veterinary work. Sometimes, for me, insect eating has been simply a way of acknowledging cultural diversity. In 2010, in Kunming, a friend had served me deep-fried bamboo worms. I ate them to be polite. They tasted like French fries, but with heads. My friend said he preferred them chewier. I never thought about them much after that. I certainly had not thought about them as ingredients for human health.
Is consuming insects good for human health? Researchers over the past decade have begun to tease that apart. Some think it might not be useful to use the all-encompassing term insect at all; we don’t lump cows, pigs, chickens into one culinary category. Which insects are we talking about? What are they fed? Were they farmed or foraged? Which stages of the insects are we eating? Do we eat them directly or roasted and ground up?
The overall research indicates that, in general, the usual farmed insects (crickets, locusts, mealworms, soldier fly larvae) have high levels of protein and other important nutrients. If insects are foraged by small groups in Laos, they provide excellent food supplements. Large scale foraging in response to global markets can be incredibly destructive, but soldier fly larvae fed on food waste and used as a substitute for ground up anchovies for farmed fish (as Enterra Feed in Canada does) improves ecological sustainability.
Entomophagy alone might not save the planet, but it does give us an unprecedented opportunity to rethink how we produce and harvest protein.
The author enjoys insects from the Dong Makkhai forest-products market, just outside of Vientiane, the capital of the Lao Peoples Democratic Republic.
Between 1961 and 2018, world chicken production increased from 4 billion to 20 billion, pork from 200 million to over 100 billion pigs, human populations doubled from 3.5 billion to more than 7 billion, and life expectancy (on average) from 52 to 72 years. These dramatic increases in food production are the result of narrowly focused scientific studies, identifying specific nutrients, antibiotics, vaccines and genetics. What has been missing is any sort of peripheral vision: what are the unintended consequences of our narrowly defined success?
If we look more broadly, we can see that this narrowly defined success led to industrial farming, which caused wealth, health and labor inequities; polluted the environment; and created grounds for disease outbreaks. Recent generations of Europeanized people inherited the ideas of eating cows, pigs and chickens, along with their products, so we were focused only on growing them as efficiently as possible. With insects, we have an exciting chance to start from scratch. Because, for Europeanized people, insect eating is so strange, we are given the chance to reimagine our whole food system in consultation with local experts in Asia and Africa (many of them villagers), and to bring together the best of both locally adapted food production and global distribution.
For this to happen, we will need to change the dietary habits of the big meat eaters. How can we get accustomed to eating bugs? There’s no one answer, but there are a few ways. In many cases, insects are ground up and added as protein supplements to foods like crackers or bars. In certain restaurants, the chefs want you to get used to seeing the bugs as you eat them. At Le Feston Nu in Paris, the Arlo Guthrie look-alike bartender poured me a beer and brought out five small plates, each featuring a different insect in a nest of figs, sun-dried tomatoes, raisins, and chopped dried tropical fruits: buffalo worms, crickets, large grasshoppers (all just crunchy and no strong flavour, maybe a little nutty), small black ants (sour bite), and fat grubs with a beak, which I later identified as palm weevil larvae, tasting a bit like dried figs.
Some entomophagy advertising has used esthetically pleasing presentations in classy restaurants. In London, at the Archipelago restaurant, I dined on Summer Nights (pan fried chermoula crickets, quinoa, spinach and dried fruit), Love-Bug Salad (baby greens with an accompanying dish of zingy, crunchy mealworms fried in olive oil, chilis, lemon grass, and garlic), Bushman’s Cavi-Err (caramel mealworms, bilinis, coconut cream and vodka jelly), and Medieaval Hive (brown butter ice cream, honey and butter caramel sauce and a baby bee drone).
The Archipelago restaurant in London serves up a Love-Bug Salad: baby greens with an accompanying dish of zingy, crunchy mealworms fried in olive oil, chilis, lemon grass, and garlic.
Some chefs, like Tokyo-based Shoichi Uchiyama, try to entice people with sidewalk cooking lessons. Uchiyama's menu included hornet larvae, silkworm pupae, and silkworms. The silkworm pupae were white and pink and yellow. We snipped off the ends and the larvae dropped out. My friend Zen Kawabata roasted them in a small pan over a camp stove in the street to get the "chaff" off. We made tea from the feces of worms that had fed on cherry blossoms—the tea smelled of the blossoms. One of Uchiyama-san’s assistants made noodles from buckwheat dough that included powdered whole bees.
At a book reading in a Tokyo bookstore, someone handed me a copy of the Japanese celebrity scandal magazine Friday, opened to an article celebrating the “charms of insect eating.” In a photo, scantily-clad girls were drinking vodka and nibbling giant water bugs dubbed as toe-biters, along with pickled and fried locusts and butterfly larvae. If celebrities embraced bug-eating, others might follow. When asked to prepare an article on entomophagy for the high fashion Sorbet Magazine, I started by describing a clip of Nicole Kidman delicately snacking on insects.
Taking a page from the success story of MacDonald’s, we might consider targeting children and school lunches. Kids don’t lug around the same dietary baggage as the grownups, and they can carry forward new eating habits for the long term. When I offered roasted crickets to my grandchildren, they scarfed them down. I asked my five-year-old granddaughter what she thought: she preferred the mealworms to the crickets – they didn’t have legs that caught in her teeth.
Entomo Farms in Ontario, the province where I live, was described in 2015 by Canadian Business magazine as North America’s largest supplier of edible insects for human consumption. When visiting, I popped some of their roasted crickets into my mouth. They were crunchy, a little nutty. Nothing to get squeamish over. Perhaps the human consumption is indeed growing—my wife, at least, has joined me in my entomophagy adventures. When we celebrated our wedding anniversary at the Public Bar and Restaurant in Brisbane, Australia, the “Kang Kong Worms” and “Salmon, Manuka Honey, and Black Ants” seemed almost normal. Of course, the champagne helped.