Science & Our Food Commentary Series
By Marcus Glassman, Research Associate, Global Agriculture & Food
In the US and around the world, future food security is a constant concern. By 2050, an estimated nine billion people will need to be fed and the food to feed them must come from somewhere on our already crowded planet. Complicating the problem of scale is another, arguably larger, challenge: How does agriculture continue to produce at current rates, much less increasing rates, in the face of climate change? Many look to biotechnology for answers.
For a microcosm of the challenges facing agriculture in a hotter, more crowded world, look no further than Bangladesh. Bangladesh is a country approximately the size of Iowa with a population density roughly 33 times greater than the US and physical territory dominated by low-lying river delta and costal lands. The impacts of climate change are all amplified here: Rising sea levels degrade low-lying coastal lands and drive saline water further upriver and inland into irrigation canals and ground water; agriculture is dependent on seasonal rains, where heavy monsoons can flood out fields and late or lacking monsoons mean drought and crop failure; and increasing temperatures in the already tropical climate mean crops are more susceptible than almost anywhere else to heat stress and crop decline.
These challenges are real, current, and worsening. But in Bangladesh, the US, and around the world, plant scientists are using biotechnology to solve them.
Flooding is arguably Bangladesh’s greatest agricultural threat. Rice provides approximately 70 percent of the calories consumed by the average Bangladeshi; although rice grows partially submerged in paddies, most rice varieties—especially those farmers favor—cannot survive for more than a few days fully submerged. In India and Bangladesh alone, flooding destroys four million tons of rice annually, enough to feed 30 million people.
But there are rice varieties not favored by farmers—low yielding and unprofitable to grow—that can survive flooding. A variety from Orissa, India, can survive for two weeks fully submerged, but despite attempts since the 1950s to cross-breed the Orissa rice’s flood-tolerance into commercially viable rice strains, results were uniformly underwhelming: The rice genome is complex, and moving just one trait from one variety to another biotechnology is nearly impossible. However, in the 1990s, scientists at UC Davis, funded by USDA grants, identified the gene in the Orissa variety responsible for its food-tolerance. Using genetic engineering (GE), they moved the selected gene into the genome of commercially favored rice varieties, and the result was a rice plant that produced grain at commercial volume, but could survive two weeks of flooding. This GE rice is not currently grown commercially, but does illustrate the potential for the technology.
Genetic engineering is not the only biotechnology solution to climate change problems. Marker assisted plant breeding, for example, couples genetic sequencing technology with traditional breeding techniques to solve the kind of problems that plagued early attempts to cross-breed Orissa rice. In marker assisted breeding, the genome of two plants with separate desired traits—for example, a commercial rice plant with high grain yields, and a flood-tolerant Orissa rice plant—are sequenced. Then, the two plants are crossbred through natural plant breeding techniques. The non-GE, non-biotech offspring of that crossbreeding contain any number of traits from either parent plant. Plant breeders then sequence the genomes of those offspring plants, and identify exactly which plants inherited the traits they wanted—and those are the handful of plants used to develop new varieties. Using traditional breeding alone, this process would take years if not decades, but with the assistance of biotechnology, desired results can be achieved in just a handful of plant generations. Using marker assisted plant breeding, researchers at the International Rice Research Institute (IRRI) in the Philippines have successfully crossbred rice varieties that combine commercial grain yields and Orissa rice's flood tolerance, and have distributed those non-GE seeds to more than four million farmers across Asia.
At IRRI, research into marker assisted breeding is underway to create rice varieties that can tolerate high-salt environments, extreme heat and cold, drought, and poor quality soils. The approach is still new, and the results have largely yet to reach scale—but the need for such rice varieties hardly needs explanation. In Bangladesh alone, 2.4 million acres of potential farmland lies fallow due to high salinity, a problem only worsening as sea levels rise. Desired traits and technologies can be combined, too; for example, a rice variety bred to contain marker assisted breeding-derived salt tolerance and GE flood tolerance could help farmers reclaim those flood prone, salt-contaminated farmlands left fallow as sea levels have risen. The possibilities are enormous.
Adapting agriculture to a changing climate is just a start: Biotechnology can actually help to reduce agriculture’s contribution to global warming altogether. Growing rice is a leading source of methane, a greenhouse gas 84-times stronger than carbon dioxide. Rice agriculture produces between 25-100 million metric tons of methane annually; this methane comes from bacteria that feed off the carbohydrates in the rice plants’ roots in the oxygen-free soils of rice paddies. But just recently, scientists in Sweden, China, and the US have successfully inserted a gene from a barley plant into that of a rice genome, causing the plant to spend more energy growing a carbohydrate-rich stalk at the expense of its roots, which become comparatively small and underdeveloped. This small change to the rice plant causes as much as a 90 percent reduction in methane production from rice paddies, a significant reduction in rice agriculture's greenhouse gas footprint.
It’s said that if crops don’t adapt to climate change, neither will agriculture, and neither will we. But whereas resource-rich countries like the US have the luxury to debate which solutions they will eventually adopt, countries like Bangladesh, for whom climate change is a real and current disaster, solutions are needed today. Biotechnology—genetic engineering and otherwise—offers the greatest opportunity we have to reverse the agricultural losses climate change has already inflicted, and our greatest chance to create an agricultural system with the resistance needed to feed ourselves in a hotter, more peopled future. Biotechnology’s role in agriculture is at times controversial, but there is no denying that it is absolutely necessary to approach climate change with all tools at our disposal.
Read additional posts in the Science & Our Food series:
- Food Security, Climate Change, and Biotechnology: A Look at Bangladesh, July 28
- The Environment and GMOs: Pesticides, Promises, and Squandered Possibilities, July 21
- Golden Rice: Solution or Symbol?, July 14
- Hawaiian Papayas and Florida Oranges: Combating Disease with Genetic Engineering, July 7
- Public Perceptions and Understanding of Genetically Modified Foods and Labeling, June 23
- Scientists and the Public Struggle to See Eye-To-Eye on Science and Technology, June 16