Green Revolution 2.0
Feeding humanity as the climate changes will require crops that are more productive, hardy, and diverse than ever.
THE MOONSHOT: To feed a projected 9.8 billion humans in 2050, farmers will have to produce an estimated 50% more food than they produce now. That’s partly because today’s staple crops will be unable to yield enough food when they are challenged in tomorrow’s hotter, stormier, more drought-stricken world. In many places, warming already is reducing crop yields, and with carbon emissions and temperatures rising faster than anticipated even a few years ago, the problem will almost surely worsen. Moreover, new efforts to boost yields must avoid the downsides of previous ones — increased carbon emissions and unsustainable use of fertilizers, chemicals, and water. As the International Food Policy Research Institute puts it: Our agriculture scientists, policy-makers, financiers, and farmers need to pull off a triple win of “adapting to climate change, increasing crop yields, and mitigating greenhouse gas emissions.”
THE PHILANTHROPY OPPORTUNITY: The world’s greatest humanitarian crop-breeding initiative to date, the Green Revolution of the 1960s and 1970s, was driven by philanthropy. But funding of crop improvement research for the developing world has stagnated just as yields of major global staple crops such as corn and wheat are faltering due to climate change. The main organization conducting research into climate-ready crops for the developing world, CGIAR, based in Montpellier, France, is funded at under $1 billion for all crops and regions of the world combined, and has suffered recent budget cuts. Meanwhile, researchers are calling for increased investment in breeding of drought- and flood-hardy varieties of major crops, and of higher-yielding varieties of already-robust, nutrient-rich “orphan crops” — among them millet, sorghum, cowpea, and cassava. Transforming the agricultural sector so that it abounds with diverse, regionally appropriate crops that can secure the global food supply and prevent mass hunger and malnutrition in a changing climate is a moonshot project worth embracing. Philanthropic commitment could further the cause in many ways, including by accelerating crop-improvement research and developing the markets and distribution networks to get seeds to farmers and crops to eaters.
In 1944, Norman Borlaug, an Iowa-born agronomist who had recently graduated from the University of Minnesota, took a leap of faith. He abandoned his job developing chemicals for the U.S. military and moved his family to a remote outpost in central Mexico to breed wheat. The Rockefeller Foundation had realized that smart government investment in research had enabled U.S. farmers to post record harvests and improve citizens’ health and nutrition. But poorer countries such as Mexico, which lacked a robust agricultural research program, were lagging. So the New York-based philanthropy placed a bet on a few driven and innovative scientists, some basic lab infrastructure, and a mandate to feed millions.
Borlaug toiled for more than a decade in sun-scorched Mexican fields, recording the results of thousands of breeding crosses between wheat varieties in search of new plants with exceptionally high yields, sturdiness, and disease resistance. Along the way, he discovered that he could squeeze a second breeding cycle into each year by shuttling seeds between Mexico’s hot desert and cooler coastal climates. The results — a doubling of Mexican wheat yields — were transformative for farmers, who were able to produce far more and boost the country’s food security. High-yielding seeds made their way into much of the rest of Latin America as well. In the late 1960s, as some warned of impending famine in India and Pakistan, Borlaug helped get thousands of tons of his best seeds shipped to these rapidly growing South Asian nations. With encouragement and subsidies from national governments for fertilizer and irrigation, farmers planted the new, more productive varieties. High-yielding rice soon delivered more food-security gains across much of the Asian continent and Pacific Rim nations.
Whether these agricultural advances averted actual famines is debatable. What is indisputable is that the Green Revolution, as the program enabled by Borlaug’s and other breeders’ innovations came to be called, dramatically improved nutrition on a global scale. And because malnutrition is a major driver of infant and child mortality, the improved crops saved the lives of millions. For his achievements, Borlaug won the 1970 Nobel Peace Prize, becoming the first agronomist to do so.
Today, the world faces a challenge every bit as severe as the one that Norman Borlaug took on in 1944. Global population continues to climb rapidly — on its way to an estimated 9.8 billion by 2050, according to the United Nations. The world’s farmers will need to produce 1.5 times as much food as they do today just to accommodate a projected double whammy of population and income growth, which is likely to create increased demand for resource-intensive foods such as meat. Climate change is multiplying the challenge by driving temperatures upward and shifting weather patterns in ways that threaten to stall or reverse the past decades’ hard-won gains in crop yield.
Last year, the Intergovernmental Panel on Climate Change (IPCC), the body responsible for synthesizing scientists’ findings on climate change, released a special report on how climate change could impact food production. What it found was alarming. Of three crops that provide 40% of the world’s daily calories, two — wheat and maize — are already suffering reduced yields due to climate change. The third staple — rice — has been holding its own, so far.
Farmers in Europe, Australia, and southern Africa are already seeing yield reductions. An analysis of yields of the world’s top 10 crops, which account for 83% of calories produced on land, found that climate change had reduced production by about 1% overall. As temperatures rise, along with the intensity of droughts and storms, more and more of the world’s regions will be unable to coax the same yields from their farm fields. A 2018 paper in the Proceedings of the National Academy of Sciences estimated that simultaneous corn crop failures in multiple global regions is likely to occur, on average, once every 14 years under a 2° C warming scenario. Such events, the authors warned, could send global food prices skyrocketing and foment civil unrest.
The Global Commission on Adaptation, a high-level body headed by leaders of the United Nations, the Bill & Melinda Gates Foundation, and the World Bank, put it equally starkly in a report released last September: “Climate change is already making food insecurity worse; it has reduced the global yield growth of wheat and maize as well as the yields of many other crops in Africa and elsewhere. Developing countries are experiencing 20 percent more extreme heat than in the late 1990s. And the number of undernourished or food-insecure people grew by between 37 million and 122 million to more than 800 million between 2014 and 2017… Absent adaptation, researchers now estimate that climate change will depress growth in global yields by 5–30 percent by 2050.”
Another sobering reality, says agriculture researcher Cynthia Rosenzweig of the National Aeronautics and Space Administration (NASA), emerged from the special IPCC analysis, whose team of some two dozen coauthors she co-led. Among other things, the researchers reviewed recent research on food crops grown under elevated carbon dioxide (CO2) conditions. In the past, Rosenzweig says, there was “a muted response” to climate change from crop scientists, because many believed that higher atmospheric CO2 levels would boost crops’ growth, offsetting temperature- and weather-related losses. That hope has largely vanished. Recent studies have revealed that plants grown under artificially elevated CO2 levels aren’t the same as those growing at today’s levels. They have less protein and fewer nutrients, so you have to eat more of them to get the same nutritional benefit. That means climate change’s bite into food security could be larger than previously thought.
With climate change cutting into the world’s food supply just as it needs to dramatically grow, experts around the globe are calling for a Green Revolution 2.0. The first revolution delivered a much-needed hedge against food insecurity in Asia and Latin America, albeit at the ongoing cost of making much of the world dependent on energy-, water-, and chemical-intensive farming methods. And it leaned heavily on a precariously narrow base of crops whose vulnerabilities are now being exposed by climate change as well as new, virulent variants of diseases such as wheat stem rust, which Borlaug warned against in a New York Times op-ed a year before his death in 2009.
“Climate change is already making food insecurity worse; it has reduced the global yield growth of wheat and maize as well as the yields of many other crops in Africa and elsewhere.” — Global Commission on Adaptation
The Green Revolution 2.0 must feed a growing population with the added challenges of providing resilience to climate change and getting it right environmentally. Next-generation agriculture must be more diverse in its crop portfolio and more sustainable across the board. Foods that are unfamiliar to many of us — sorghum, cassava, fonio — will need to feed millions more than they do today. Perennial crops, such as long-lived variants of wheat and other annual grains, and food-producing trees, which do not require soil plowing and planting every year, will need to play larger roles.
“We need to boost production in Africa, but we don’t need to follow the same path as the [first] Green Revolution,” says Cheikh Mbow, a crop scientist at the University of Pretoria in South Africa and co-leader of the IPCC panel.
Resilience in the Rough
On a recent winter day, with the previous night’s snow clinging to shivering Midwestern grasses outside, Todd Mockler and his colleague Nadia Shakoor basked in the warmth of brightly lit greenhouses at the ultra-modern Donald Danforth Plant Science Center in the suburbs of St. Louis. The center, founded in 1998 by Ralston-Purina heir William Henry Danforth on land donated by the agricultural giant Monsanto (now Bayer), is the world’s largest independent nonprofit research institute devoted to plant science.
Mockler and Shakoor are experts in tweaking the genetics of plants to make them better, stronger, and more productive. Controversial as the practice often has been, such gene-tweaking in blockbuster crops such as soy and corn has made companies like Monsanto rich enough to partially fund an entity like the Danforth Center. What Mockler and Shakoor do is less controversial, because they rely on traditional breeding techniques such as selecting optimal varieties for varied growing conditions, bolstered by valuable intelligence garnered with modern gene- and trait-analyzing technologies.
The plants Mockler and Shakoor were observing on this morning superficially resembled corn, with thick, stiff central stalks from which long, floppy leaves radiated. But rather than produce ears jutting to the side of their stalks, these plants generate poofs of red or yellow kernels at their tops, which tower as high as small street lights. These are stalks of sorghum, a grain that in the form of bread flour and other products, feeds millions on the African continent.
Sorghum was domesticated some 5000 years ago in or near what now is Sudan and has been an important food for Africa’s people ever since. That status derives from several great properties: It can grow in poor, dry soils in which water-loving plants such as corn and rice struggle. Its seeds also pack more fat per weight than either of those staples.
But sorghum could do so much more, Mockler says. That’s because its yields are a shadow of what is possible. Sorghum growers in Africa harvest 1 ton or less per hectare (a unit of area comparable to the interior of a standard quarter-mile race track). American corn growers, by contrast, pull in between 5 and 15 tons from a typical hectare.
We tend to think of crop plants as products of “nature,” but we shouldn’t. Today’s blockbuster crops — corn, wheat, soybeans, rice — are finely tuned mini-factories; they are the end products of thousands of years of selection and refinement that convert sunlight, water, and nutrients into food. Especially in the past century, buoyed by an amalgam of academic, government, and industry research, scientists have dramatically increased these plants’ productivity. Corn yields per U.S. acre, for example, have ballooned almost tenfold since the 1920s, fueling the most productive agricultural system the world has ever known.
Breeding programs funded by philanthropies have had some success at translating such gains to the developing world. The original Green Revolution is the best-known example. More recently, the International Rice Research Institute (IRRI), a CGIAR unit based in the Philippines, bred a flood-tolerant rice variety. The Gates Foundation funded final development and distribution of the rice seeds to farmers. Flooding — the other side of the drought coin — will also increase in some areas as a result of climate change, and traditional rice varieties often drown when submerged for long periods. The new IRRI-developed rice, which can spring back after a field dries out, was described by one Indian farmer in a 2011 New York Times story as a “miracle.”
A second success story comes from Africa, where, despite Borlaug’s efforts, Green Revolution 1.0 never arrived. Lack of roads and markets, among other factors, stymied the fertilizer and seed distribution that the revolution depended on. So yields in Sub-Saharan Africa have remained perilously low even as other regions of the world have prospered.
In 2006, the Rockefeller Foundation, the Gates Foundation, the U.S. Agency for International Development, and other funders launched the Alliance for a Green Revolution in Africa (AGRA). Focusing on 12 countries, the consortium ultimately invested more than $200 million in a collection of related efforts: crop improvement research, training of African breeders, and launching of companies to distribute 670 new varieties of seeds that alliance researchers developed. By 2017, 120 African companies the project supported were selling about 150,000 tons of seeds to farmers. For some crops in some countries, yields doubled.
“For us this was a fantastic outcome,” says Joseph DeVries, who led the alliance’s seed research for the Rockefeller Foundation and now heads the Seed Systems Group in Nairobi. “I’d never seen anything that could be done at a centralized level like AGRA was doing, that could actually reverse crop-yield decline and start to see an uptick in farmer productivity.”
Ethiopia has proven an especially successful case, thanks to the combined effects of multiple donor-funded programs. Maize yields there have doubled since 2000, helping turn a once drought-stricken nation into a breadbasket for its region.
But many of the gains have occurred in already well-researched crops, like rice and corn. Sorghum, by contrast, is an “orphan crop.” Unlike its celebrity cousins, it has received little attention from crop scientists. As a result, while research-guided yields of the big crops have skyrocketed globally since the mid-1970s, yields of sorghum, says Mockler, “have literally been flat.”
Other orphan crops include millet, a protein-rich grain staple in both Africa and countries of the south Asian subcontinent including India, and cassava, a starchy root commonly eaten in the tropics. The problem of improving orphan crops and upgrading them into global commodities is urgent: Sub-Saharan Africa is the world’s least food-secure region, and the one whose population is projected to grow the fastest. Along with the Indian subcontinent, it’s the region considered most vulnerable to future heat, drought, and floods.
In an especially worrying trend, undernutrition rates in Sub-Saharan Africa began ticking upward in 2015, after years of steady decline.
“In Africa, in semi-arid regions, we used to have just as much as needed,” says Mbow. “Now the rainfall is declining. In those areas with high population density, it’s very likely we’ll have a lot of social challenges related to food insecurity.”
Nurture the Orphans
Crop experts believe that upping the yields of orphan crops while maintaining their nutritional benefits could be one of the surest and sustainable ways to avert those challenges and secure a robust food supply in the decades ahead.
“The big growth we saw over the past half century, including the Green Revolution, was pretty much focused on Asia and Latin America, and the big crops,” says Keith Wiebe, a climate researcher at the International Food Policy Research Institute (IFPRI) in Washington, D.C. “There’s a debate that, all right, they’ve had their turn — what about sorghum and millet and cowpeas … that tend to be more important for poorer farmers in poorer regions?”
Mockler and Shakoor of the Donald Danforth Plant Science Center, with help from the Gates Foundation, have accepted the challenge. While they are following in the conceptual footsteps of Norman Borlaug, they have the luxury of doing so at a state-of-the-art research center rather than a remote, ramshackle field station. And instead of the tweezer and the seed envelope, their tools of choice are the gene sequencer, the climate-controlled growth chamber, and a suite of high-tech cameras and sensors for analyzing plant traits. All told, these scientists may be growing the world’s most scrutinized sorghum.
Their goal is to dramatically speed up the process of finding genes crucial to sorghum’s ability to grow big heads of nutrient-filled seeds in the vast diversity of conditions found on the African continent. All varieties selected by the project will be made freely available to African breeders.
Mockler and Shakoor are not quite starting from scratch. Sorghum bicolor’s genome was sequenced in 2009 by an international consortium of scientists. But as with the human genome, that was only the beginning. The plant has some 34,000 genes — roughly 1.5 times as many human beings do — and for a given trait, dozens of genes can be involved. For example, Mockler’s team has found 70 genes that could help regulate how sorghum uses water.
Now the researchers must match specific genetic profiles to desired traits such as hardiness to drought and other stressors, nutrient density, and, of course, high yields. Mockler and Shakoor began by gathering 1400 sorghum varieties from all over Africa and India and sequencing the genomes of each. Then they grew the varieties in basement chambers at the Danforth Center where temperature, humidity, and other variables can be precisely controlled. As seedlings, the plants — each in a pot trackable with bar codes and RFID codes — move upstairs and go through an intense evaluation process. Each day, they are weighed, watered, loaded onto a conveyor belt, and robotically shuttled through a series of cameras — regular, infrared, and fluorescence — to quantify traits such as height, size, health, water use, and photosynthetic efficiency under treatments mimicking conditions such as abundant rainfall or drought. The gathered data are correlated with thousands of genetic markers that the researchers have identified. The technique, known as rapid phenotyping, allows Mockler and Shakoor to quickly pick the most promising candidates for further testing.
“An experiment that might take 3 months to do [in the field], you can [now] take a seedling, use the marker to check its DNA and know what its phenotype will be,” Mockler says. “It’s much faster and cheaper … The more you turn the crank, the more breeding cycles you achieve, the faster you get the genetic improvement you want.”
The plants that ace the gauntlet of exams graduate to the greenhouse to be pollinated. During a visit by this writer in February, two lab technicians were draping paper envelopes over the tops of plants that were starting to flower to ensure that each plant was pollinated by its own genes, not those of other varieties. For the tallest plants, the greenhouse technicians have to climb a stepladder to reach the flowers. When the seeds mature some 6 weeks later, the technicians will collect the seeds and send them to test fields in Arizona, whose hot, dry climate resembles that of the African countries Mockler’s is designing seeds for. There, the plants continue their scrutinized life thanks to a device funded by the U.S. Department of Energy and the Gates Foundation. Rolling down a pair of roughly 400-meter-long tracks, a 28-meter-wide gantry carries a minivan-sized scanner armed with more than a dozen sophisticated cameras and sensors over acres of plants. The project’s website calls it “the world’s largest agricultural robot.”
The robotic system inspects every plant at least once a day; some scans are taken at night. Data are fed into the cloud and subjected to machine-learning algorithms, which the researchers hope will reveal never-before-imagined metrics of plant health and yield potential, perhaps based on subtle spectral properties of leaves. Finally, Mockler sends his best plant candidates to agriculture agencies in Ethiopia, Mali, and Senegal, where breeders grow them in fields to test their suitability for local conditions.
If this high-tech, multi-continent effort sounds time-consuming and expensive, it is. Taking a new variety from the lab to the farm field can easily take a decade. If the seeds can reach smallholder farmers working small plots of land, it could help them produce more for themselves and their families, providing a crucial hedge against hunger and malnutrition that are part of what keeps life expectancies in Sub-Saharan Africa more than a decade below those in most other parts of the world. But better seeds could also catalyze profound economic changes. They could allow subsistence farmers to generate a surplus, which they could use to enter the market economy, make money, and afford a higher standard of living. They could help more women — who do the majority of farm labor in many parts of Africa — to get educated and pursue other careers. It all starts with better seeds.
Mockler hopes he can identify and characterize seeds that, if spread across the African continent, could yield millions of tons of additional food annually. “You could expect a 1 or 2 percent increase per breeding cycle,” Mockler says. “If we got 10 or 15 or 20 percent [in total], that would be a nice improvement.”
It’s been proven time and again: Investment in agricultural research delivers real, quantifiable benefits for human nutrition, longevity, and prosperity. “One dollar invested in agricultural research for developing countries yields multiple dollars in benefits, with the bulk of those benefits accruing to poor people,” leaders of IFPRI and the Gates Foundation wrote in a September 2019 op-ed.
But those investment dollars have become scarce. After the Green Revolution placated fears of imminent famine last century, donor interest in helping poor farmers waned. From the 1980s to the mid 2000s, aid for agricultural development in poor countries dropped by almost half, and crop research centers were forced to lay off staff.
As the world faces intensifying climate change, experts now warn that the crop research system has become perilously underfunded. In its report, the Global Commission on Adaptation called for a doubling of the budget of CGIAR, which runs 15 research centers around the globe.
A handful of philanthropies — chiefly the Gates and Rockefeller Foundations — along with governmental aid agencies have traditionally shouldered much of the burden for agriculture aid in the developing world. For Green Revolution 2.0 to succeed, new players need to join the game, says DeVries of the Seed Systems Group.
To philanthropies that have been sitting on the sidelines, his message is clear: “There is room for you to have major impact.”
As the International Food Policy Research Institute puts it: Our agriculture innovators, policymakers, and financiers need to pull off a triple win of “adapting to climate change, increasing crop yields, and mitigating greenhouse gas emissions.”
Not surprisingly, however, for a system as complex and multi-faceted as the global food system, there are many opinions about where a boost to the research ecosystem could deliver outsize benefits. Some believe that a massive expansion of basic research on the genomics and phenomics of the hundreds of crop plants mostly ignored by agribusiness could yield enormous benefits to poor and climate-stressed regions. Others see big gaps in applied research into everything needed to get high-yielding seeds from the test field to the dinner plate — from launching of new seed companies to development of distribution networks and agricultural extension services to behavioral research for aligning consumer demand with resilient foods.
Mockler and Shakoor, not surprisingly, see needs at the basic-research end of the spectrum. With the advent of rapid gene sequencing and high-throughput phenotyping, crop breeders have gone almost overnight from being data starved to data flooded. The Arizona field scanner alone can fill five terabyte-sized hard drives in a day. But tools to store, process, and analyze the reams of phenotype data that modern plant breeding experiments generate are lacking, Shakoor says, meaning that potential discoveries go unmade.
The second half of the crop development research marathon — testing and selection of varieties in the countries whose farmers need them — also faces funding shortfalls. Researchers in developing countries often lack basic infrastructure that American crop scientists take for granted. When Mockler arrived at the research center of the Ethiopian Institute of Agricultural Research, for example, he discovered that scientists there lacked basics such as reliable irrigation equipment and electronic data-entry and barcoding systems. He and his collaborators decided to invest initial grant money into building capacity before jumping into high-throughput phenotyping.
Research needs multiply when crop scientists turn their attention to obscure crops. The African Orphan Crops Consortium seeks to sequence and annotate the genomes of 101 traditional African food crops and put the results in the public domain for researchers to build on. These include well-known crops such as bananas and yam and obscure ones such as fonio, a small grain essential to poor farmers in some West African countries but virtually unknown — and unstudied — anywhere else. Shakoor has launched a side research project on fonio, but she currently has no funding for it.
Even when basic research is well funded, the fruits of research may fail to be fully deployed because of missing pieces further down the production and distribution pipelines. Perhaps the clearest example of this disconnect involves hybrid seeds, one of the greatest innovations in crop breeding. Hybrids are crosses between two different varieties of a plant that are the same species but not closely related. When genetically distinct parents’ genes mix, deleterious recessive traits often are suppressed, leading to increased resilience and higher yields — a phenomenon known as “hybrid vigor.” The advent of hybridization in the 1930s kicked off the boom in American crop productivity that continues to this day. Mockler rates it “the easiest way to get a bump in yields.”
But because hybrid seeds result from crosses between specific varieties, individual farmers cannot reliably produce them. They must be produced and distributed every year by seed companies. “Making hybrid seed is almost like a manufacturing process,” Mockler says, involving “super-precision planting, mating, seed collection, seed verification. It’s hard and it’s expensive.”
Sub-Saharan Africa’s seed companies lack the scale to reach the continent’s more than 200 million mostly smallholder farmers, who may cultivate just a few acres each and lack the income to buy seeds anew each year. As a result, many farmers save seeds and replant them the following growing season. The practice provides a measure of self-sufficiency, but largely prevents farmers from taking advantage of innovations such as hybridization and the related distribution systems that have dramatically boosted yields and incomes elsewhere. The World Bank found that fewer than a quarter of cereal crop seeds planted in Sub-Saharan Africa in 2000 were improved varieties.
Still, some hybrid seeds for Africa have been developed. The $120-million, philanthropy-supported Water-Efficient Maize for Africa project has produced 100 new, drought-tolerant varieties now available for sale in Africa, according to Bayer crop researcher Mark Edge. But the project has struggled to get the seeds distributed and planted. A recently announced effort, Gates Ag One, which will be based in St. Louis, seeks to tackle some of the distribution and business development challenges that have stymied dissemination of agriculture innovation.
The Alliance for a Green Revolution in Africa also achieved some of its best results with hybrid maize, and the alliance’s investment in seed companies has helped get seeds to farmers in the 12 targeted countries. DeVries now hopes his new organization can extend the benefits of improved seeds to the rest of Sub-Saharan Africa.
When genetically distinct parents’ genes mix, deleterious recessive traits are suppressed, leading to increased resilience and higher yields — a phenomenon known as “hybrid vigor.” The advent of hybridization in the 1930s kicked off the boom in American crop productivity that continues to this day.
For other crops, hybridization will have to wait. After learning about Sub-Saharan Africa’s infrastructure, distribution, and policy challenges, Mockler decided to study only open-pollinated sorghum varieties. He anticipates that farmers, after getting improved sorghum seeds from African breeders, will save and reuse seeds rather than purchase new ones each year. “Initially I was a little naïve about how basic research could so easily translate to improved varieties” in the developing world, he says.
In some places, climate-resilient crops already exist but have fallen out of fashion. Narasimha Rao, an environmental scientist at Yale University, points out that human behavior, including consumption habits and practices, constitutes a mostly unexplored and potentially rich research arena relevant to the looming food crisis.
The Green Revolution did more than boost yields, Rao points out. It changed eating habits. Traditionally, Indians ate a lot of millets — protein- and nutrient-rich, drought-hardy cereals. But when high-yielding rice arrived, many farmers switched over, and millions of eaters followed.
“Millets began to be seen as food for the poor,” Dinesh Kumar of Earth 360, a nonprofit in the southern state of Andhra Pradesh, India, told NPR in 2017. “Rice was aspirational.”
As Indian consumers and farmers turned to rice, farmers came to rely on the annual monsoon, which floods rice paddies at just the right time. But one consequence of climate change is that the monsoon is becoming erratic. If it became necessary, artificial irrigation of the more than 100 million acres of Indian rice fields would be daunting.
Rao suspected that one solution to this challenge could be to return to what worked in the past. He recently co-authored an analysis showing that if a sizable number of Indian farmers switched from rice to hardier cereal crops such as millets and sorghum, they could dramatically boost the country’s climate resilience and nutrition. But there’s a possible showstopper: Many Indians today have never eaten millet or sorghum.
So a next step involves understanding consumer preferences and how to market climate-resilient foods to 21st-century eaters, Rao says. Also needed is research and development of processing techniques to turn these crops into appealing food products. Improving yields is important, he says, but “at the end of the day, if people don’t want to eat this stuff, there’s no use in researching the supply side.”
Green Revolution 2.0 is primarily about plant agriculture. But a large part of the solution to our 21st-century food challenges resides in the animal kingdom. Global meat consumption reached a record 327 million tons in 2018 — more than 40 kilograms per person — according to the United Nations’ Food and Agriculture Organization (FAO), and every indicator suggests it will continue to rise. Indeed, 85% of the world’s grain is fed to animals, not directly to humans.
The animal agriculture system is both a driver and a victim of climate change. Depending on how you count, the global food system is responsible for between one eighth and one quarter of all carbon emissions, and methane-emitting ruminants — primarily cows — are the worst offenders. On the vulnerability side, livestock need large amounts of water, and hot temperatures can stress them.
Some hope that the rapidly growing alternative protein movement could eventually replace much of animal agriculture with plant-based and lab-grown meat. But cultural, political, and economic inertia guarantee that animal farming will be a reality for some time. So researchers are working to change livestock systems to be more climate resilient and less impactful on land. Among the top ways to do this is through silvopasture, a form of agroforestry that involves planting trees where livestock feed. Project Drawdown, an organization that evaluates ways of reducing carbon emissions, ranks widespread adoption of silvopasture ninth on its list of top climate solutions. If expanded from the current 351 million acres to 554 million acres globally, Project Drawdown estimates, silvopasture could sequester 31.2 gigatons of CO2— nearly a year’s worth of global emissions — in soil and biomass. Moreover, the group says, though the expansion would cost some $42 billion to implement, farmers could ultimately generate $699 billion in additional revenue from tree-based products.
Researchers and farmers around the world — from Mexico to South Africa — are now experimenting with planting hardy, nutrient-dense trees in pastures. One standout is moringa, a small tree native to south Asia but now cultivated throughout the tropics. Moringa, a legume, harbors nitrogen-fixing bacteria and can supply cattle with both shade and protein. It’s so hardy that Mbow of the University of Pretoria says some call it the “never-die” tree. He believes that moringa and other African trees also hold untapped potential as bases of commercial food products for people and could do double duty as arboreal reservoirs for storing carbon. In a small plot in his hometown of Dakar, Senegal, he is growing and studying moringa, baobab, and native palms for these multiple purposes. Elsewhere, researchers in China sequenced the moringa genome in 2015, and teams in Mexico and at the University of California Davis are also running projects to improve moringa genetics, indicating strong potential for this jack-of-all-trades plant.
Another potentially vast source of food is the six-legged kind. Insects can pack as much protein as meat while requiring far less energy, land, and water to produce. Crickets, for example, can convert half of their feed into body mass, compared to one-fifth to one-tenth for beef cattle. One 2015 study estimated that insects cultivated on less than 100,000 hectares — less than the land area of Los Angeles — could eliminate global undernutrition.
In many countries, insects are already on the menu. In Oaxaca, Mexico, for one, people munch crickets as a popcorn-like snack. Globally, some two billion people are estimated to include insects in their diets, taking advantage of some 1900 species, FAO estimates. But a widespread disdain for insects and the “ick” factor prevent them from catching on in much of the rest of the world. In many Western countries in particular, eating insects is taboo and may run afoul of religious food prohibitions.
There are efforts to expand the profile of this underrated food source. A 2013 FAO report that sparked interest in insect-eating, or entomophagy, reported that insects “offer a significant opportunity to merge traditional knowledge and modern science in both developed and developing countries.” But research gaps exist up and down the insect food development chain, from basic research into insect rearing practices to demand-side research on how to make insects palatable to unaccustomed consumers.
Yet another major food source could emerge from new ways of farming in the ocean. Seafood already helps feed more than three billion people and provides some 15% of global dietary protein. But fisheries are being depleted: FAO estimates that almost 90% of fisheries are either overfished or fished to their maximum sustainable yield. And fish, too, are vulnerable to global warming; a recent study found that local populations of marine species are disappearing at twice the rate of land-based species.
A new ocean-based movement is afoot (or afin?) to provide more seafood more sustainably. Known as mariculture, this emerging practice involves the intensive production of seafood using approaches analogous to those common in large-scale, land-based agriculture, such as raising fish in off-shore pens, cages, or raceways. (The broader category of aquaculture also includes raising fish in inland and near-shore waters; it has exploded since 1990 and already provides much of the supply of certain species such as catfish and shrimp.)
Mariculture is just starting to take off, but it is the fastest-growing sector in the food world, according to one recent analysis. A 2017 study suggested that 100 times as much fish as humans currently consume could be produced using just 0.015% of the ocean. By intensely concentrating fish production, the thinking is, most of the ocean and its species can be left alone. A great challenge for the sector would be to avoid adding to ocean pollution and other environmental problems with such intense production; shrimp farming, for example, is one of the major global drivers of destruction of mangrove forests that protect global shorelines.
In his Nobel Prize acceptance speech in 1970, Norman Borlaug cautioned that the task of improving the world’s crops was far from complete. “Perhaps the term Green Revolution as commonly used is premature, too optimistic, too broad in scope,” he said. “The reality is that only some crops have been modified; only some farmers have benefited.”
A new generation of agricultural revolutionaries is now seeking to complete what Borlaug and his colleagues began. They have the advantage of new technologies and techniques, but also arguably even greater challenges to surmount: a surging human population, a precariously overused planet, and a changing climate that will make each gain in agricultural productivity harder to eke out. Sustainably feeding the world will be one of the defining challenges of the coming century.
Gabriel Popkin is a freelance writer based in Mount Rainier, Maryland.