As the effects of climate change on our global ecosystems continue to reveal themselves, fears are growing that it could threaten food security, particularly a vital source of protein that has sustained humans for centuries. Luckily, bean breeders at the Consultative Group for International Agricultural Research (CGIAR), a global food research consortium, have announced the discovery of 30 new lines of “heat-beater” beans that could keep production from crashing in large swaths of bean-dependent Latin America and Africa.
Thanks to research supported by the Bill and Melinda Gates Foundation, the World Bank and the governments of over two dozen countries, the new beans are a landmark result of urgent efforts by CGIAR to develop new crop varieties that can thrive in drastic weather extremes. The bedrock of this research is CGIAR’s “genebanks,” which preserve the world’s largest seed collections of humanity’s most important staple crops. Using new genomic tools, plant breeders are now better able to unlock the potential of the genebanks’ vast genetic diversity by probing nearly 750,000 samples of cereals, legumes, roots and tubers, trees, and other important food crops — along with their wild relatives — to identify genes with traits such as heat, flood, and drought tolerance or resistance to pests and disease that can help farmers adapt to environmental stresses.
“This discovery could be a big boon for bean production because we are facing a dire situation where, by 2050, global warming could reduce areas suitable for growing beans by 50 percent,” Steve Beebe, a senior CGIAR bean researcher, said in a statement.
Often called the “meat of the poor” for the affordable protein they provide, beans are a nutritionally dense foundation of food security for more than 400 million people in the developing world, also offering fiber, complex carbohydrates, vitamins and other micronutrients. In addition to heat tolerance, CGIAR experts are simultaneously breeding for higher iron content to enhance the beans’ nutritional value.
The path to drawing down emissions
Learn more about how we can feasibly achieve 'Drawdown' for a climate-safe future from Lynne Twist, Senior Advisor for Project Drawdown, at SB'20 Long Beach.
“As a result of this breakthrough, beans need not be the casualty of global warming that they seemed destined to be, but rather can offer a climate-friendly option for farmers struggling to cope with rising temperatures,” said Andy Jarvis, a CGIAR climate change expert.
Many of the new heat-tolerant beans are “crosses” between common beans including pinto, white, black and kidney beans; and the tepary bean — a hardy survivor cultivated since pre-Columbian times in an area that is now part of northern Mexico and the American Southwest.
The heat beaters emerged from the methodical and exhaustive testing of more than 1,000 bean lines, work originally geared toward developing beans that could tolerate poor soils and drought. The focus turned to heat tolerance following an alarming 2012 report from CGIAR scientists warning that heat was a much bigger threat to bean production than previously believed; rising temperatures were thought likely to significantly disrupt bean production in Nicaragua, Haiti, Brazil and Honduras, and the African countries of Malawi, the Democratic Republic of the Congo, Tanzania, Uganda and Kenya.
“Incredibly, the heat-tolerant beans we tested may be able to handle a worst-case scenario where the build-up of greenhouse gases causes the world to heat up by an average of 4 degrees Celsius (about 7.2 degrees Fahrenheit),” Beebe said. “Even if they can only handle a 3 degree rise, that would still limit the bean production area lost to climate change to about five percent. And farmers could potentially make up for that by using these beans to expand their production of the crop in countries like Nicaragua and Malawi, where beans are essential to survival.”
Led by CGIAR researchers, a team of the world’s leading bean experts quickly moved to cultivate test plots on Colombia’s Caribbean coast, where they deliberately exposed beans to nighttime temperatures well above what they can normally tolerate. Scientists also established greenhouses so that temperatures could be dialed up on demand.
“We confirmed that 30 heat-tolerant lines are productive even with nighttime temperatures above 22 degrees Celsius (about 72 degrees Fahrenheit),” Beebe said. “Normally, bean yields start to falter when the temperatures exceed 18 or 19 degrees Celsius (about 64 to 66 degrees Fahrenheit).”
Among the beans found to be especially heat tolerant was one that was recently introduced into commercial production in Nicaragua, chiefly because of its performance in drought conditions. Tested in dry conditions in Costa Rica, it yielded more than twice the amount of beans compared to what farmers were currently cultivating. Beebe said scientists now have evidence that the superior performance was due not just to drought tolerance but also heat tolerance.
“What this shows us is that heat may already be hurting bean production in Central America far more than we thought and farmers could benefit from adopting the new heat-beater beans right now,” he said.
To provide a sustainable and cost-effective way to combat malnutrition, CGIAR researchers embarked more than a decade ago on a pioneering program to improve the nutritional content of staple food crops that the poor rely upon.
Some of the heat-tolerant beans identified by Beebe and his team have also been deliberately bred to be higher in iron in an effort to tackle malnutrition. In developing countries, deficiencies of this essential micronutrient afflict one out of every two preschool children and pregnant women, making them highly susceptible to anemia and compromising children’s growth and cognitive development. While beans are already high in iron, these new varieties could eventually provide up to 60 percent of daily iron needs for women and children — almost twice the iron of non-improved beans.
“A couple of years ago, when climate change experts warned that rising temperatures could be devastating for bean production, we were asked how this would affect high-iron beans,” said Beebe. “Now, I am confident that we can confront this challenge as well. We can develop more iron-rich beans that are also heat-tolerant. These beans would deliver even greater benefits than expected because they could be grown more widely.”
Speaking of super-nutritious foods that are inexpensive to cultivate and much more environmentally sustainable than many of today’s commodity crops, Oakland startup Kuli Kuli is working to increase the market Stateside for a superfood native to Africa called moringa — known as one of the most nutrient-dense trees in the world with high levels of protein, iron, calcium, vitamins and antioxidants. The tree could play an important role in helping sustain our nutrition in a water-constrained world — as it grows well in poor soil with little water — and for vegetarians and rural farmers who cannot afford meat, as it contains the essential amino acids methionine and cystine, which are among the hardest amino acids for the body to acquire from plant-based diets.
And a number of companies are working to develop and scale crickets as a sustainable alternative to resource-intensive protein staples such as beef. Cricket protein is particularly low in fats and carbohydrates; contains all of the essential amino acids; is high in micronutrients such as iron, calcium and vitamin B; and provides almost as much calcium as milk and more iron than beef. And as water shortages become a grave concern around the world, crickets provide a win there, too: 100 gallons of water can create 238 grams of cricket protein, versus 6 grams of cow protein or 18 grams of chicken protein.