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Saving Our Food Supply in the Face of Climate Change

In the already-scorching Southwest, a group of scientists, ranchers and farmers are figuring out how to adapt the current agricultural system for a hotter, drier planet.

A smoldering vista southeast of Tucson, Arizona—a city that saw 68 days of temperatures at 100°F or higher last year, and averages less than 12 inches of rainfall annually. Photos by Russ Schleipman.

Gary Paul Nabhan teetered on a hunk of volcanic rock on Tumamoc Hill, the University of Arizona’s century-old Desert Laboratory, high above the city of Tucson, and pointed down through a forest of saguaro cactus at some lines of reddish stone hugging the hillside. “See that?” he asked me. “See what?” I said, squinting into the distance. “Terraces! This whole hill is terraced,” he said. “One of the missions of the Desert Lab was to find evidence of ancient food cultivation, and for the longest time they couldn’t see what was right under their noses.”

During his decades of fieldwork, Nabhan has spotted these terraces all across the region, along with the plant that still accompanies them: agave, the spiky succulent from which mezcal and tequila are made. With a juicy heart rich in carbohydrates, agave has been harvested throughout the Southwest as an important food source for at least 8,000 years. The native peoples terraced the hillsides to capture the sparse rain-water, and edged them in agave, whose deep roots held them together. You can still find the descendants of those agaves lining the edges of these old, crumbling terraces. But few modern-day folks ever noticed, because we don’t think of the agave plant as food.

And that is Nabhan’s point. “If we’re going to start adapting our food production in this region to the changing climate,” he told me, “we’re going to have to start thinking outside of the box.” Not just about the plants we grow, but how we grow them in our ever-warming world.

That’s something the 66-year-old Nabhan has been doing his whole life. He came to Arizona as a young ethnobotanist in the 1970s and never left, celebrating the state’s overlooked cultures and foodways in books such as Gathering the Desert, Forgotten Pollinators, Coming Home to Eat and Chasing Chiles. Along the way, he won a MacArthur Fellowship, founded Native Seeds/SEARCH, which preserves and promotes the indigenous food plants of the Southwest, and started the Center for Regional Food Studies at the University of Arizona. Through it all, Nabhan has argued that the wisdom of ancient people farming with limited means might again prove useful.

It’s Too Darn Hot

To the untrained eye, Dennis Moroney’s 25,000-acre ranch may look like nothing more than sweltering scrubland, but to his herd of Criollo cattle it looks irresistible. The special breed of cow has adapted to eat cacti and other desert plants and to withstand the Arizona heat.

That time is now. For a century, the Southwest has been an agricultural powerhouse, transforming its abundant sunshine into abundant food with the help of irrigation. The federal government’s massive dam projects of the 20th century, such as the Hoover and Glen Canyon dams, diverted the Colorado River’s water to the booming cities and farms of the Southwest, which enabled production of most of our winter veggies, from kale to kohlrabi. But a megadrought that began in 2000 reduced the Colorado’s flow to a fraction of what it used to be. Lake Mead, the biggest reservoir on the river, reached its all-time low in 2016, and farmers across the region have been warned to prepare for shortages. The problem isn’t simply lack of precipitation. “At least half the drought we’re experiencing is due to increased temperature, not diminished rainfall,” explained Jonathan Overpeck, Ph.D., who shared a Nobel Prize for his work as lead author of the Intergovernmental Panel on Climate Change’s climate assessment.

Nobody has looked more closely at the effects of climate change on the Southwest than Overpeck has. And he doesn’t sugarcoat the facts: “It’s gonna get hotter,” he told me. “That’s something we know with great confidence.” And when it gets hotter, plants burn through their water supplies faster, which means that even if there is normal precipitation in the future, it may not be enough to sustain the crops grown here.

That’s alarming in a place that already experiences more than 60 days a year of 100-plus-degree weather. And it’s not just a problem in the Southwest. Drought and record temperatures have recently scorched everywhere from California to the nation’s breadbasket. Overpeck calls this the “Southwesternization of the United States,” a phrase that should give chills to anyone who’s ever gotten misty-eyed at the sight of an amber wave of grain, an orchard studded with Honeycrisps or a green pasture speckled with happy Holsteins. Even farmers in places like the Midwest and the Northeast, which have abundant rainfall, are starting to irrigate. “It blows your mind,” Overpeck said. “Michigan. New York. Places that shouldn’t need to do it. Because they’re warmer now, the crops really get affected.”

In fact, the science predicts that for every 1°C of warming, corn yields in the Midwest fall by 6 percent. And that means by 2050, we will see a decrease in yield of around 15 percent. By 2100, we could be facing a reduction of 50 percent if serious steps aren’t taken to mitigate climate change. Wheat and rice, which along with corn provide more than half of the world’s calories, will be similarly affected. Equally troubling: agricultural yields overall in the U.S. are expected to drop by up to 6 percent for each 1°C uptick. With average temperatures projected to rise 3°C by the end of the century (by conservative estimates) that translates to a nearly 20 percent decrease in crop yields. Livestock and poultry production will also take a serious hit, not just from having less feed, but also due to heat stress, which lengthens the time it takes for animals to get to slaughter weight and can cause fertility problems. Dairy yields are predicted to plummet by as much as 30 percent, as well, because heat and humidity negatively affect milk production.

Even the USDA, about as nonalarmist a source as you could find, is sounding the alarm. In a major 2015 report titled “Climate Change, Global Food Security and the U.S. Food System,” it warned that higher temperatures will dry out soil, stress plants and animals, and make water management difficult. “As climate change continues and temperature increases of 1–3°C are coupled with changes in precipitation timing and intensity, yields and farm returns are projected to decline,” it said. Plants wilt. Animals don’t thrive. Precipitation comes as damaging storms and flash floods—that erode soil and destroy crops—instead of snowpack that slowly trickles out of the mountains throughout the growing season.

It all sounds pretty terrifying, but Nabhan sees opportunity. “We have so many tools to work with here,” he told me. He explained that a nexus of innovators were already re-inventing food production in the Southwest. To do so, they’re throwing out the bad lessons of the 20th century, learned when temperatures were stable and water was cheap and plentiful, and embracing ideas from both the future and the distant past. Then he asked me if I’d like to meet some of them.

From the heights of Tumamoc Hill, I gazed across the Sonoran Desert to a ribbon of highway rising toward tawny peaks in the distance. “You mean like a desert road trip?” I asked hopefully.

Exactly, he said. It may look barren, but out there is where we’d find the real iconoclasts—farmers who were making the desert bloom in unexpected ways. Nabhan tempted me with tales of tender, cactus-fed beef and the best bread I’d ever eat. “What we’ll be seeing is a living laboratory for innovation,” he said. “Some of these ideas may never get wind in their sails, but the few that make it will have enormous impact, not just in desert areas, but in temperate zones too.” In other words, what’s happening in the Southwest may be a preview of the feverish future in store for all of us. All the more reason to take a close look at this “living laboratory” of the borderlands.

And so we set out through the sagebrush and tumbleweeds to meet the future of farming, to discover some new ideas and some very old ones.

Visiting the Living Lab

At St. Anthony’s monastery in Florence, Arizona, lemon groves flourish in even the driest environments thanks to drip irrigation, which is up to 95 percent more efficient than conventional watering methods. Brother Minas prunes grapevines for the wines produced at the monastery.

East of Tucson, we drove through the golden, windswept grasslands of Arizona’s Sky Islands. We dropped south into the blackened creosote plains of the Chihuahua Desert, rolled through Tombstone, ignoring the O.K. Corral attractions lining the road, then drove miles down a lonely road until we pulled up at the off-the-grid adobe ranch house of Dennis and Deb Moroney. I stared from the house to the Mule Mountains in the distance and wondered if Nabhan had lost his mind. I saw a sun-parched plain scattered with cactus, agave and mesquite. I saw nothing edible. This was the future of farming? It looked more like the future of famine.

A trim man sporting a cowboy hat, a luxuriant white beard and piercing blue eyes stepped off the porch and greeted us warmly. This was Dennis Moroney, and I soon learned that he viewed that landscape very differently than I did, mostly because he saw it through the eyes of his Criollo cattle, who found the desert thoroughly delicious.

Most ranchers in the West raise Black Angus and Hereford—British breeds that are designed to live in a land of abundant rain and endless grass. They eat heartily and bulk up quickly, but they aren’t made for deserts. They’re too heavy and stocky to range widely, so they hang out in the easy lowlands and graze on any grasses they find, leaving those areas barren. After that, ranchers have to buy feed, which greatly raises the carbon footprint as well as costs.

Moroney wasn’t interested in being a part of that system. “We want our place to be a model of sustainable, bioregionally appropriate agriculture,” he told us as we walked his dry pastures. With his beard and philosophical demeanor, he reminded me of a lean and clean version of The Dude from The Big Lebowski, and he was prone to the occasional Dudeism of his own. “You can fight the landscape, or you can adjust your system to live with it,” he said. “Sometimes going backwards is making progress.”

The Moroneys’ key adjustment was discovering Criollo, a breed of cattle that were a perfect fit for the landscape. Criollo are tough. They were brought to Mexico by the Spanish in the 1500s and had already adapted to an arid environment in Spain. But left to forage for themselves in the harsh environments of northern Mexico, they got even tougher—and smarter. Instead of grazing in the heat of the day, Criollo learned to shelter under trees and even feed at night on the hottest days. They also became connoisseurs of mesquite and other desert plants. “We’ve seen these guys eat things that a conventional cow won’t even look at,” Moroney told me. “They’ll reach inside a cholla cactus and lick the buds off. They’ll eat prickly pear in the wintertime. They utilize a phenomenal number of plants.” The Criollo can venture farther from water sources and browse more widely than conventional cattle, as well. “They’re really good about using a big piece of country,” Moroney explained. “The difference is amazing. We find the Criollo bedded down on the tops of ridges.”

Because Criollo have horns and other qualities that make them unsuitable for feedlots, the Moroneys decided to go direct, selling their cactus-fed beef at farmers’ markets and to a butcher who supplies around 20 high-end eateries in the Tucson area. In just a few years, they have developed a tremendous following for the tender, marbled meat and the profits have helped enable them to pay off their entire ranch.

When I asked Moroney the secret of his success, he said “right-brain thinking.” Instead of the industrial version of agriculture, which calculates inputs and outputs, his solution was long and careful observation of the land. “You have to get into a poetic frame of mind to really be one with this landscape.”

That poetic mindset is what helped -Moroney see the other big opportunity in the desert. Over a lunch of Deb’s rich, spicy chile-and-mutton stew, made from the same hardy Navajo-Churro sheep that she uses to create stunning hand-spun yarns, Dennis gestured toward their rangeland and talked about its bounty. But all I could see was agave.

Bingo, said Dennis. “We literally have millions of them out there.” Nabhan nodded knowingly. Mexico never stopped thinking of agave as a crop, building it into a billion-dollar industry in some of the most inhospitable land imaginable. Now a new generation of Arizonans is contemplating the same thing. Each of those agaves on the Moroneys’ ranch has enough sugar in its core to make several bottles of mezcal. Dennis and a few other would-be mezcaleros in Arizona think agave could be the most sustainable of all desert crops. They harvest the hearts in spring, roast them in mesquite-coal pits for 30 hours, then double-distill the syrup into a drink with all the smoke and fire of a small-batch Oaxacan mezcal. “So far we’ve just been making enough for our own internal needs,” Dennis said, stroking his white beard contentedly. But with Arizona’s recent loosening of restrictions on commercial distilling, expect the succulent spirits of the Grand Canyon State to come alive.

Planting Hardier Crops

Tepary beans are extremely drought-resistant.

We pulled out of the Moroneys’ ranch gnawing on homemade jerky and headed for the Tohono O’odham Reservation, where Nabhan had told me I could score some tepary beans and white Sonora wheat, two ancient O’odham crops. If the best answer to thriving on a drier planet is turning to the plants that were doing it long before modern agriculture came along, I figured the O’odham, who have lived in the Sonoran Desert for millennia, might be pretty good guides.

The O’odham reservation covers a vast stretch of desert between Tucson and the Mexican border. In the center of it sits the San Xavier Mission, a white stucco masterpiece built by O’odham laborers in the late 1700s and known as the Sistine Chapel of the New World for the stunning frescoes that line its walls and ceiling. Just down the street is the San Xavier Co-op, a tiny, nondescript trailer. Expecting little, I stepped inside and walked into a world of native foods. There were gourds and dried cholla buds and things I couldn’t identify. A brief treasure hunt led me to bags of tepary beans and white Sonora wheat flour. I scooped them up, hoping to lean on Nabhan’s culinary expertise back at his house later that week.

The tepary is one tough little hombre. It resembles a pinto bean, but the tepary is like the pinto’s survivalist cousin. It’s one of the most drought-tolerant crops in the world, keeping its cool in temperatures as high as 114°F. Its leaves track the sun like little solar panels, but in the heat of midday they fold up to protect themselves. It also waits to germinate until the first summer monsoons hit—a common strategy for desert plants—and then it grows fast before things can dry out too much. A tepary is ready to harvest in 60 days, while most beans need twice as long. Although the Tohono O’odham never lost their taste for these deliciously earthy beans, now researchers and breeders around the world are embracing them as a hedge against food insecurity.

White Sonora wheat hasn’t gone global yet, but it’s one of Nabhan’s great passions. Missionaries brought it to northern Mexico in the 1600s, and for the locals, who knew only corn tortillas, it was love at first sight. With the sturdier flour, they could make larger and larger tortillas that held together like magic. The burrito was born.

The drought-tolerant white Sonora powered local mills across the Southwest until the 1970s, when wheat production consolidated around higher-yielding modern varieties that did best in the wetter, cooler High Plains. The local mills disappeared, and white Sonora with them. But a handful of farmers in northern Mexico kept the variety alive, and a few years ago Nabhan got his hands on some seed and spread the word about its impressive qualities. “It’s a nice, soft, low-gluten wheat with this incredibly delicious, sweet, nutty, almost creamy flavor,” he said. “I just love it.”

Nabhan isn’t alone. Heritage-grain pioneer Glenn Roberts of Anson Mills proclaimed it one of the best cake flours in America, and James Beard Award-winning chef Chris Bianco made it famous at his Phoenix restaurant Pizzeria Bianco. Today, white Sonora has again become a distinctive piece of Southwest cuisine, thanks to the growing network of farmers and bakers who have embraced it.

Northwest of the Tohono O’odham Reservation sits a surreal forest of 12-foot-high saguaro and ocotillo. We drove through it for hours until suddenly the cactus forest opened onto a mirage-like oasis: a medieval edifice rising from the bleached earth, surrounded by lush groves. Black-robed figures glided between the buildings and gardens. I blinked in disbelief. It felt like something out of The Arabian Nights, but this was St. Anthony’s Greek Orthodox Monastery, a little piece of the Mediterranean plunked down in the desert. Brother Minas greeted Nabhan with a bow and walked us through acres of olives, citrus and wine grapes flourishing on little more than drip irrigation and prayer. “Don’t grow what you want to eat,” he thundered at us, robes rippling in the wind. “Eat what you can grow!”

Drip irrigation delivers water directly to a plant’s roots through small plastic tubes. It loses nothing to evaporation and can cut a farmer’s water use in half while at the same time raising yields. The method has taken off across the desert Southwest, but St. Anthony’s stands out for its sheer scale and lushness despite soil conditions that are particularly inhospitable. Worldwide, drip is being used for everything from rice to tomatoes. Just 20 percent of U.S. farms currently use it, but that number is rising fast. Thanks to the recent drought, about 80 percent of California’s almond growers have converted to drip. As water becomes increasingly scarce, expect the rest of the country to follow suit.

Looking Back, Moving Forward

Drought-resistant white sonora wheat is baked into this gorgeous loaf of bread by Don Guerra of Barrio Bread is Tucson.

After several days on the road, we were excited to settle into Nabhan’s house, high in the Arizona hills, in part because we had all the makings for a unique feast. In the light of an orange sunset, we ladled beds of earthy tepary beans onto our plates and topped them with slabs of beef from the Moroneys. I drizzled peppery olive oil from St. Anthony’s onto slices of white Sonora bread and greens from Nabhan’s greenhouse. The monastery had blessed us with the largest lemon ever grown, and that got squeezed over everything. In our glasses, a little local mezcal.

Nabhan knows farms in the Midwest or Northeast can’t solve their problems with agave and olive trees. That’s not his point. “The suite of plants might not be applicable to other places,” he allowed as he spooned more beans onto our plates, “but the ideology is.” Like Dennis Moroney said: Get to know your land. Figure out what it wants to do and how you can help it. “Innovation occurs on the margins,” Nabhan continued. “You start with small experiments in improbable places. Those are the disruptive technologies that may get us through when the conventional ones stop working. They may seem insignificant now, but when the crisis really hits, they’re going to be in such demand.”

The world is changing. We know the future climate is going to be more extreme than the past, and more challenging. But everything I’d seen in Arizona showed me that no matter how Southwesternized the rest of the country becomes, it could still be a beautiful, vibrant place to live and to eat if we continue to put innovative minds on it.

Nabhan and I filled our plates once more and toasted the purple desert sky. What struck me about every single ingredient of our meal was that it had been farmed mindfully. It had been grown by people who paid attention and didn’t do things just because that’s how they’d always been done. That’s a trait America’s farmers were once famous for, and it’s one we’re rediscovering just in time.


Rowan Jacobsen is the author of several books, including American Terroir. He received a James Beard Award for his Eating-Well feature “Or Not to Bee.”


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