This article is part of the magazine, "The Future of Science In America: The Election Issue," co-published by LeapsMag, the Aspen Institute Science & Society Program, and GOOD.
For youth climate activists, Earth Day 2020 was going to be epic. Fueled by the global climate strikes that drew millions of young people into streets around the world in 2019, the holiday's historic 50th anniversary held the promise of unprecedented participation and enthusiasm.
Then the pandemic hit. When the ability to hold large gatherings came to a screeching halt in March, just a handful of weeks before Earth Day, events and marches were cancelled. Activists rallied as best they could and managed to pull off an impressive three-day livestream event online, but like everything we've experienced since COVID-19 arrived, it wasn't the same.
Add on climate-focused candidate Bernie Sanders dropping out of the U.S. presidential race in April, and the spring of 2020 was a tough time for youth climate activists. "We just really felt like there was this energy sucked out of the movement," says Katie Eder, 19-year-old founder and Executive Director of Future Coalition. "And there was a lot of cynicism around the election."
Photo credit: Cassell Ferere
Saad Amer leads climate justice/racial justice march in the summer of 2019.
Benji Backer gets a tour of Michigan University's Nuclear Lab
Credit: Keegan Rice.
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."
For David Walden, a Southern Californian, surfing is a lifestyle, not a hobby. The 38-year-old works nights at a seafood restaurant to leave his mornings free for surfing.
While the surfers are doing what they love, they are also collecting information that is helping scientists better understand the ocean.
"Once you fall in love with the ocean, you need it like a daily cleanse or refresher," he says. "The positive mental and physical effects of the ocean, the endorphins and dopamine, keep you addicted in a good way."
Given his dedication to surfing, Walden was delighted when he became one of more than 200 surfers last year to test Smartfin, a 5-1/2-inch surfboard fin that contains a circuit board, a rechargeable battery, a GPS device, a sensor that captures temperature to one-hundredth of a degree, and a motion sensor that tracks the movement of the waves. While Walden and his fellow surfers are doing what they love, they are also collecting information that is helping scientists better understand the health of the near-shore ocean and how its chemistry is shifting due to climate change.
"I'm excited to be a part of it," Walden says. "I like to tell people I surf for science."
Back on shore, the surfers download the Smartfin data via a smartphone app so they can be accessed by scientists and other interested parties. (You can see where Smartfin surfers go at this interactive map.)
By putting sensors directly onto surfboards, oceanographers can collect data to help them better understand the global-warming related changes occurring in coastal oceans in temperature, salinity, and pH, all properties that have huge implications for the species that live in near-shore ecosystems.
There is much unknown about coastal waters because it's so difficult to obtain meaningful measurements. Traditional methods to monitor the close shore, such as bottle samples and buoys, are time consuming and expensive and tend to get damaged by the surf.
The Smartfin is the brainchild of Dr. Andy Stern, a retired neurologist. He and his brother-in-law, sculptor and filmmaker Todd McGrain, run The Lost Bird Project, a nonprofit devoted to raising awareness about climate change and other environmental issues. Stern brought his super fin idea to engineer Benjamin Thompson, who spent several years creating a prototype in his garage workshop. Smartfin was further developed by scientists at the Scripps Institution of Oceanography at the University of California at San Diego.
"The big challenge was to make a sensor small enough to fit in the fin but still produce good measurements," says Andreas Andersson, an associate professor of geoscience research at Scripps.
The Surfrider Foundation, a surfer-led nonprofit environmental organization, came aboard two years ago to distribute the Smartfin to its San Diego members.
Smartfin has also made a splash with scientists at the University of the Sunshine Coast in Queensland on the eastern coast of Australia. They are using the fin's temperature sensor to better understand how climate change is affecting the movement and distribution of marine life. And at the Plymouth Marine Laboratory in Plymouth, United Kingdom, the Smartfin's precise temperature readings of the near-shore ocean's surface are being used to improve the accuracy of satellites that monitor the ocean from hundreds of miles away.
"It's hard to talk about climate change in a way that's not boring or gloomy, but there's nothing gloomy or depressing about surfers and Smartfin."
"The hope is that Smartfin will improve the satellite measurements, which could improve the retrieval of temperature data around the world," says Dr. Phil Bresnahan, Smartfin's lead engineer at Scripps. In the future, the fin will include sensors to measure pH, chlorophyll (algae), dissolved oxygen, and turbidity (water clarity).
Stern envisions a time when thousands of surfers, paddle boarders, and other water enthusiasts worldwide will have Smartfins and be downloading data for scientists and environmentalists. Right now, there are approximately 70 surfers in the San Diego area using Smartfin and an additional 30 globally.
Scientists have plenty of evidence that global warming is largely caused by humans. Now they are trying to figure out what the long-term effects of climate change may be. For example, scientists are trying to predict which sections of coral reef, which house 25 percent of marine species, are most vulnerable so interventions can be developed to save them. Because of its small size, Smartfin is ideal to measure temperature changes in coral reefs.
Smartfin was also intended to be an educational tool. "It's a great way to start a different conversation about climate change," says Stern. "It's hard to talk about climate change in a way that's not boring or gloomy, but there's nothing gloomy or depressing about surfers and Smartfin. People want to hear more."
Turning surfers into citizen scientists makes perfect sense, says David Pasquini, 35, a longtime surfer who works for the British Consulate General's office in Oceanside, Calif. "Anyone who spends a lot of time in the ocean is aware of the changes happening in the ecosystem, the climate," says Pasquini. "Everyone asks, 'What can I do?'" Surfing with Smartfin, Pasquini feels like he is giving back.
"I know the data will be analyzed and eventually used to make a policy that helps with climate change. That's a great feeling--just by surfing, doing something you love, you're contributing."