Book ReviewVOLUME 17 ISSUE # 29

How climate change is affecting our food

If you lived through 2021, you witnessed some of the most extraordinary weather since recordkeeping began.

In the mild and rainy Pacific Northwest, a catastrophic heatwave practically roasted berries on the vine. For the first time ever, the federal government declared a water shortage at Lake Mead, the country’s largest reservoir, cutting the water supply for Arizona farmers. Enormous wildfires broke out in California, Washington state, Turkey, Greece, and Siberian Russa.

Meanwhile, extreme rainfall triggered deadly floods in North America, Germany, and China. And in another historic first, rain fell at the Greenland Summit, a place that until now has been frozen year-round. All these weather events affect the food supply in one way or another, whether it’s destroying crops, leaving areas too harsh for farming, or triggering swarms of locusts and other pests.

Beyond individual events, though, climate change overall is transforming agriculture. In some countries, farmers’ yields of wheat, corn, and other crops are declining thanks to severe weather. And in other areas, new weather patterns have boosted them. In the U.S., annual precipitation has increased over the northern and eastern parts of the country, while it’s fallen in the South. That affects what farmers are able to grow.

“In North America over the last couple decades, we’ve seen a northward shifting of growth regions for some crops, like corn,” says Todd Mockler, PhD, a principal investigator at the Donald Danforth Plant Science Center in St. Louis. “There’s more corn being grown in southern Canada than ever, when 30-40 years ago it wasn’t a hospitable environment.”

At the same time, though, farms in Kansas and Oklahoma have less water for irrigation, he says. “In real time, we’re seeing production agriculture being impacted by climate change.” And it’s not just affecting plants. Fewer and smaller animals are growing in pastoral Africa. Warming oceans reduce food production from shellfish aquaculture and fisheries. According to the United Nations’ Intergovernmental Panel on Climate Change, millions of people in Africa, Asia, Central and South America, and elsewhere already have climate-related food insecurity. Around half of the world’s population has extreme water scarcity over the course of a year.

But all is not lost. Large-scale efforts from the Food and Agriculture Organization of the U.N. and other organizations are underway around the world. They’re using a strategy known as “climate-smart agriculture” to increase yields, reduce risks to crops and livestock, manage the use of water and land, and lower the emission of greenhouse gases.

Genetic engineering in the crops themselves also helps. For instance, most varieties of rice will die if left under water for more than 3 days. In India and Bangladesh alone, flooding destroys enough rice each year to feed 30 million people. But a genetically engineered variety introduced in 2013 offers hope. It can survive up to 2 weeks under water. “My lab and other labs have been working on climate resilience for many years,” says Pamela Ronald, PhD, whose lab at the University of California, Davis, came up with the new variety. “More than 6 million farmers are growing that rice now. It’s been really important for some of the poorest farmers in the world.”