Some of our favorite foods are under threat as climate change gathers speed. With only 15 plants contributing to 90 percent of humanity’s energy intake, losing just one staple crop could spell disaster. Yet there are more than 7,000 varieties of edible plants worldwide.
Researchers at Kew have been working on expanding food diversity in an effort to “future-proof” our diets. They’re looking at underutilized foods, both wild and cultivated, and asking which ones make sense for our hotter, drier future.
Our favorite crops are “not necessarily the ones that can withstand climate change in the future,” Ulian says. “They’ve been selected for color or yield. You need to have alternatives that are adapted to local conditions.”
Some of Kew’s biodiversity initiatives involve working with communities to conserve knowledge of local food plants and begin cultivating wild species. A project in Lebanon and Jordan focuses on Gundelia tournefortii, known as akkoub in Arabic, which is said to taste like a combination of artichoke and asparagus. You can only find it in the wild, where it grows on undisturbed rocky soil, but Kew researchers are working with local nurseries on cultivation. In addition to being tasty (locals fry the plant’s unripened flower heads in olive oil and garlic, and add them to omelets, meat and chickpea dishes), akkoub is rich in calcium and iron.
Another project looks at fonio, a grain native to West Africa. It needs very little water, which makes it a good choice for an increasingly drought-prone world. It’s high in iron, calcium, amino acids and B vitamins. It’s also gluten-free, which could make it attractive for people with celiac disease. Locals eat it as a breakfast porridge, or as a grain dish similar to couscous.
Researchers are investigating which types of fonio grow best in different conditions, such as in hot valleys or cooler, higher altitude areas. It’s extremely important to have crops adapted to specific locations, Ulian says.
“In the past, it’s been a mistake to try to somehow have all these major crops everywhere in the world,” Ulian says. “Why do we have to eat the same crops everywhere? Every country needs to think about and plan ahead for crops that are really adapted to their own conditions.”
Pandemic supply chain issues and the war in Ukraine have shown some of the hazards of depending on a globalized food supply, Ulian says. The world didn’t realize how much wheat was produced in Ukraine until it was suddenly unavailable. This has driven up food prices worldwide, hitting developing nations particularly hard.
One key to offsetting this type of loss involves looking at botanical relatives of staple crops like wheat, Ulian says. Kew scientists have been working with partners in 24 countries to find alternatives to common cultivated rice varieties. They collect the seeds from wild rice relatives, and send some to Kew’s Millennium Seed Bank, an underground storage vault of more than 2.4 billion seeds from around the globe, for safekeeping. The seeds will be studied to see if they have resilience to climate change; currently cultivated rice crops can easily be destroyed by flooding or heat.
To give us an idea of what our food future might look like, Kew recently released a list of climate-resilient foods, and is running a special summer exhibition with talks, installations and chef demos. They’ve also published The Kew Gardens Cookbook, a compendium of vegetarian recipes available in September in the U.S., that includes a few of these foods, to show the delicious side of food diversity.
Some of the foods we may be eating more of in coming years include:
Ulian’s specialty, the marama bean, is a legume native to southern Africa. Marama beans come from the Kalahari region, and are adapted to growing in exceedingly dry, sandy, nutrient-poor soil. The beans are rich in carbohydrates and minerals, and can be used to make oil and plant-based milk. They also produce a large, edible tuber, said to be sweet and tender, as well as a good source of water.
Sierra Leone Coffee
Many of us start our day with a cup of Arabica coffee, the world’s most popular brew, which is under threat due to rising temperatures and deforestation. Kew researchers have found that a rare species of wild coffee (Coffea stenophylla) from Sierra Leone is much more heat-tolerant than its cousins. Coffee is not necessary for life, of course, Ulian notes, but points out that it’s an extremely important financial crop for communities worldwide. “From a livelihood point of view, [climate change-proof coffee] makes a big difference,” she says.
In Mexico, nopales—the pads of the prickly pear cactus—are a popular vegetable, often served in tacos or with scrambled eggs. The prickly pear isn’t the only type of edible cactus. Different varieties of the drought-tolerant plant, such as the barrel, saguaro and cholla, can be stewed, pickled, juiced, or even eaten fresh (like dragon fruit), and are a good source of water, fiber and vitamins.
While Ethiopia’s enset plant does produce a banana-like fruit, that bit is actually inedible. It’s the starchy stem and roots that can be fermented into dough for bread and porridge. An enset can live for up to 12 years, and 60 plants could feed a family of five for a full year, according to Kew. That, plus the fact that it can be planted and harvested at any time of year, have earned it the name “tree against hunger.” Wild relatives of the enset can grow as far south as South Africa, which means the plant could potentially be cultivated widely. Bonus: it can be used as a building material, with its fibers reinforcing earthen walls.
Beans are already popular worldwide, but Kew scientists think they could be put to even broader use. In addition to familiar global favorites like kidney beans, pintos, favas, chickpeas, peas and lentils, hundreds more wild species could be cultivated. Take, for example, the Yeheb nut, which grows in Somalia and Ethiopia and tastes like a chestnut, or the edible lupin, common in the Mediterranean, which can be pickled for snacks or ground into flour. Beans are extremely drought tolerant, and put nitrogen into the soil, preparing it for other crops. Plus, they already grow on every continent except Antarctica.
“Ocean farming” has gained popularity in recent years, as a way of producing vegetables without fresh water, fertilizer or the use of land. Most of us are already familiar with nori, the dried sheets of red seaweed used to wrap sushi. But many other forms of seaweed are edible, from kelp (known as wakame in Japanese, and used in soups and other dishes) to dulse, often baked into soda bread in Ireland.
Pandanus, a small tree from the screw pine genus, grows across warm coastal lowlands and islands in the Asia Pacific region. Being a coastal plant, they’re used to salt spray and high winds. The female plant produces a vitamin- and potassium-rich pineapple-like fruit, and both male and female plants have aromatic leaves used to flavor jams, cakes and rice dishes, or to wrap meat and fish.
Native to Mexico’s Yucatan Peninsula of Southern Mexico, chaya produces leaves and shoots, which are also known as tree spinach. When raw, they’re highly toxic. But when boiled and simmered, they’re an excellent source of protein, vitamins, iron and calcium. They’re extremely resistant to pests, and can tolerate drought and heavy winds.