We tend to view the effects of climate change through the lens of the worst and most dramatic disasters, from hurricanes and floods to forest fires. But farmers have a more mundane fear: that as weather becomes more extreme and varied, their land will no longer support the crops they grow. We’ve grown accustomed to living in a world where salad greens thrive in California, and Iowa is the land of corn. But even in the absence of a single, catastrophic event, conventional wisdom about what grows best where may no longer apply.
“People who depend on the weather and hawk its signs every day know it’s getting wetter, warmer, and weirder, and have recognized it for some time,” Art Cullen, Pulitzer Prize-winning editor of The Storm Lake Times, a twice-weekly Iowa newspaper, wrote for us in December. “The climate assessment predicts more of it and worse. Ag productivity will be set back to 1980s levels unless there is some unforeseen breakthrough in seed and chemical technology.”
Those breakthroughs aren’t unforeseen, exactly. Crop scientists are doing all they can to breed plants that can thrive under the new environmental conditions wrought by climate change. Here’s a look at some of the ways geneticists, plant breeders, and companies are trying to make agriculture more resilient by modifying the food we eat every day—and some foods we don’t eat yet—for a brave new climate-changed world.
Potatoes don’t like the heat. Scientists say the highest yields are at moderate temperatures, at around 70 degrees during the day, and a little cooler at night. But when they get warm, the spuds instead sprout green shoots and leaves. The few tubers that do form are less starchy, and rot more quickly.
Recently, biochemists in Bavaria, Germany figured out why. A group of 19 nucleotides, they discovered, actually blocks the formation of tubers when temperature rises. Last week, those scientists announced they’d genetically modified yellow potatoes to turn those nucleotides off, and successfully grown the plants under 84-degree temperatures in a greenhouse. That bodes well for a warmer future, but the next step, the researchers say, will be to test their heat-seeking taters in the fields.
As demand for animal protein, and grains to feed livestock, continues to grow around the world, the current workhorse strains of corn, soy, and wheat may no longer suffice. After decades of tinkering, their genetics are approaching the limit, with exponential investments in breeding more efficient plants now resulting in increases in yield that are only linear, according to Pat Schnable, a plant geneticist at Iowa State University. To make matters worse, the water supply needed to grow that feed is increasingly limited in agricultural regions around the world, particularly in California.
Enter proso millet, an ancient, 12,000-year-old grain that Schnable says is going to adapt well to a warming planet. Millet uses less water per pound of grain produced than any other crop, he told journalists last year, and doesn’t need irrigation, which makes it ideal for the rapidly drying parts of the world. Currently, he said, it’s grown in western Nebraska, eastern Colorado, and South Dakota, and used mostly for high-end bird food and mushroom spawn. If his company, Dryland Genetics, can boost the grain’s yield by 20 percent, the millet could be “absolutely substitutable” for corn when farmers need to feed their cows and pigs. Plus, it’s gluten-free, and a great ingredient in seeded bread and granola bars.
Lettuce doesn’t grow in 85-degree weather, which is bad news for salad eaters everywhere. Within 100 years, scientists predict, heat could make Central California inhospitable to much vegetable production—and “America’s salad bowl” could become a dust bowl. To ward off impending disaster, five years ago, Beiquan Mou, a research geneticist with the United States Department of Agriculture (USDA), tested over 3,500 varieties of lettuce and spinach in a heat chamber, with the goal of identifying the hardiest species and isolating their heat-resistant genes, Modern Farmer reported.
Mou’s been partially successful. He’s identified over 40 green and red-leaf lettuce varieties that can be planted two months later than usual, which demonstrates increased heat tolerance. However, at four months, their leaves burn up and desiccate, according to one report. That hasn’t deterred him. A scan of his current research projects indicates he’s still working on finding the best lettuces. Meanwhile, in Brazil, where lettuce is the country’s most-consumed vegetable, a state-owned research corporation has just unveiled a new lettuce variety that resists early blooms caused by heat. América Economía reports it was developed within the company’s “genetic improvement program.”
Climate change has had an odd effect on champagne. Theoretically, rising temperatures reduce the risk of frost damage to wine grapes, and can lead to lower acidity levels. And indeed, since the 1990s, growers in the titular French region have been harvesting two weeks earlier, with bigger grapes that are more alcoholic. An earlier, fattier yield might not sound like such a bad “new normal,” but viticulturists aren’t happy. A boon today means disaster tomorrow.
To combat that, France’s champagne committee has been working with the national agricultural institute to create new varieties that mature later. They’re also thinking about some of the other problems that accompany a warmer world—like, for example, new mildews, pests or diseases.
Unlike American researchers, such as those in South Dakota who are designing cold-climate wine grapes, Europeans tend to stay away from genetic engineering. Unless genetic engineering is used, developing climate-resistant champagne could be a relatively slow process, entailing several cycles of hybridizing different champagne varietals—black pinot noir, pinot meunier, and white chardonnay among them—before finding the right mix. The researchers hope to have grown 4,000 hybrid seeds and completed their studies by 2030.
The Washington Post reports that plant breeders are developing new varieties of peaches and other tree fruits that don’t “wake up early” in warm winters, and that need fewer hours of chilling before blooming in the spring.
As reporter Adrian Higgins explains, growing plums, apples, and pears is a high-wire act, with fruits in Appalachia that must “race to flower in early spring while dodging a killing frost.” In recent years, however, mild winters have thrown off that balance. From South Carolina up to Michigan, the fruits have flowered too early, and been killed off when they were exposed to late-season frosts and hail. Five years ago, California’s cherry crop “crashed” due to the changing weather. In the Northeast, as we’ve written, almost the entire peach harvest was wiped out in 2016.
The erratic weather interferes with research too. Higgins reports that four years of freezes in West Virginia, for instance, killed peach blossoms that had been used for hybridizing. That’s a problem, because creating new fruit trees typically takes two decades of breeding, which leaves scientists with the thinnest margin of error.
Walnuts are sensitive. Hot, dry summers kill the trees. The cold, meanwhile, scares them, so in the spring, the trees don’t sprout leaves until almost a month after others. That makes the careful, timid nut especially vulnerable to the vagaries of an unpredictable climate. If a frost sweeps through an orchard late in the spring, after the leaves finally sprout, the trees can die. It’s a balancing act.
Breeding a more resilient walnut tree is particularly important in Indiana, where walnut trees account for 15 percent of logs sold, according to Charles Michler, the late founder of Purdue University’s Hardwood Tree Improvement and Regeneration Center. Researchers there have worked to breed walnuts that can withstand weather stresses, both from the heat and cold, without losing the defense mechanism that is their late-spring bloom. Meanwhile, in California, where 99 percent of the country’s walnut supply is grown, researchers are actually mapping the walnut genome, in the hopes of developing tree nuts that can better withstand pests.
It’s possible that corn is king because of climate change. Speaking last fall, Brett Begemann, the chief operating officer of Bayer Crop Science, told journalists assembled at the company’s Kansas City, Missouri facility that warming temperatures are why farmers in North and South Dakota gave up on wheat and got into kernels. With longer growing seasons, and fewer frost-free days, the farmers turned to plants better suited for less cool environments.
Today, corn bred for drought tolerance covers 22 percent of America’s total corn acreage, according to USDA’s Environmental Research Service, because a lack of water results in fewer and smaller kernels, and ultimately a smaller yield. Additionally, Begemann says, Bayer breeds cold-tolerant corn lines that can handle cooler, wetter soils, which help farmers in drought-stressed environments start their growing season earlier. In the coming years, Kansas State scientists say, expect to see more of that breeding being done through gene editing.
Around 60 percent of 124 wild coffee species are at risk of extinction, including Arabica, a version of which is found in most morning joe. To combat that threat, researchers are turning to the wild. Today, in El Salvador, the industry-backed World Coffee Research group is creating hybrid seedlings that can live in warmer temperatures. They’re doing that by grafting wild, disease-resistant varietals onto those with stronger root systems. Though the plants are stronger, and can deal with fungus, there’s still the question of temperature. As one scientist showed PBS, even the hybrids are flowering two months ahead of schedule, during the dry season, which lowers the bean quality.
If genetics fail, then coffee farmers will turn to time-tested, lo-fi techniques to cool their fields—like, for example, by adding mulch and cover crops that keep soils humid, and by casting more shade from above. These kinds of conservation practices may prove to be increasingly important because, as Art Cullen will tell you, breeding can’t fix everything. “Genetic breakthroughs cannot mask the fact that we are losing soil 10 times faster than Earth can regenerate it because of more intensive weather and tillage,” Cullen writes. And you can’t grow much corn—or coffee, lettuce, or potatoes—without soil.