How Climate Change Is Forcing Changes on the Farm
Global warming is likely to increasingly disrupt American farming with extreme heat, drought, wildfires, and heavy downpours.
As climate change’s influence on extreme weather events and deadly wildfire outbreaks becomes increasingly apparent, it’s also forcing farmers to change how they grow the food that destined for your dinner table.
One of the loudest farm alarms recently came from the U.S. government’s National Climate Assessment, which found that climate change was likely to “increasingly disrupt” American farming with extreme heat, drought, wildfires and heavy downpours. In short, a warmer climate will be harder on animals, crops, and the people who work the fields.
“Projected increases in extreme heat conditions are expected to lead to further heat stress for livestock, which can result in large economic losses for producers,” said the report, which was released late last year. “Climate change is also expected to lead to large-scale shifts in the availability and prices of many agricultural products across the world, with corresponding impacts on U.S. agricultural producers and the U.S. economy. These changes threaten future gains in commodity crop production and put rural livelihoods at risk.”
Vara Prasad, an agronomist at Kansas State University whose work was among the various studies cited in the climate report, told Seeker that warmer temperatures and more erratic rainfall are already affecting where and when crops are being planted in the central U.S.
Kansas farmers are seeing earlier spring-like weather, more heat waves, longer gaps between rainfall, and heavier downpours when the rain does arrive.
“We go on a drought for two or three weeks, and then we have pouring rain for a couple of days,” said Prasad.
In the summers, when farmers are growing crops like corn and soybeans, those swings often coincide with heat waves that can damage crops. Meanwhile, in the winter, when farmers are growing wheat, false starts to spring present another hazard.
“We get a couple of days or one week of early spring weather, which is warmer than usual,” Prasad said. “The wheat that’s been planted starts to grow, and then we get hit by a cold snap and it kills the wheat.”
Josette Lewis, who leads sustainable agriculture programs at the nonprofit Environmental Defense Fund, noted that farmers will likely face new pests or plant diseases that are moving to newly hospitable parts of the globe. And changes to how they grow their crops could lead to fights between urban and rural areas over water rights and water quality.
“Farmers are going to have to think about larger-scale changes in the types of crops they grow with respect to their access to water, or finding more creative solutions that go beyond the farm level,” Lewis said.
The natural ranges of crops are shifting generally northward in response to warmer temperatures — a pattern that can be seen worldwide — while in Kansas, Prasad said, more drought-tolerant plants are shifting toward the drier west and those that need more water are moving east.
“In some of the places [where] you’re able to grow corn, we will have to move to less water-using crops like milo or sorghum,” he said.
“Global warming is likely to boost crop yields in higher-latitude nations like Russia and Canada. But it would cause devastating declines in harvests in some of the world’s poorest regions, including sub-Saharan Africa and southern Asia.”
That may mean trying to produce new hybrid species or cultivate variations of crops like wheat or soybeans that stand up to hotter, drier conditions. Corn is already widely adapted to conditions from the tropics to the plains of western Canada, and researchers are working on producing hybrids that can thrive in the conditions that scientists expect from climate change.
“There’s a lot of genetic diversity,” Lewis said. “The multinational seed companies, as well as public researchers, have an expanding range of tools to address those.”
But until such breakthroughs happen, farmers may need to change their practices in order to maintain the quality of their soil. Tilling less often conserves water, while rotating crops like beans or oats with wheat and corn between seasons — or adding non-traditional crops like chickpeas or lentils — can increase a farm’s output of more traditional staples.
Other recent research forecasts that global warming is likely to boost crop yields in higher-latitude nations like Russia and Canada. But it would cause devastating declines in harvests in some of the world’s poorest regions, including sub-Saharan Africa and southern Asia.
The study, led by the Colorado-based National Center for Atmospheric Research, found that these effects are bigger with a global average warming of 2 degrees C (3.6 F) over pre-industrial times — the upper goal of the Paris climate accord that was signed in 2015 — than at the pact’s more ambitious target of limiting warming to 1.5 C.
While carbon dioxide is what plants crave, it may also affect how nutritious those crops will be for humans. Studies by Harvard’s T.H. Chan School of Public Health have found that crops grown in CO2-enriched environments have less protein and important minerals like iron and zinc.
But while farmers can change crops or livestock, there has to be a market for them. That may require changes in consumer choice that aren’t likely to appear overnight. That’s especially true for livestock, which consume the biggest chunk of the U.S. corn harvest.
“The amount of water to produce a pound of meat versus a pound of legumes or a pound of eggs or milk is huge,” Prasad noted. “It’s 10, 15, or even sometimes a 50-fold difference in the amount of water that’s utilized.”
“I’m not suggesting we don’t eat meat at all,” he added. But moving away from daily consumption of meat every day can help ease the effects of climate change, he said. “If consumers don’t change in terms of their diet preferences, it will be very tough.”
Lewis pointed out that such shifts have occurred in the past, especially as global trade has created new opportunities for farmers.
“We didn’t have quinoa when I was growing up. I still remember when kiwi started to become a fruit in the grocery store,” she said. But there’s less of a connection between farm and supermarket than you may think. “A relatively small portion of the dollar a food consumer spends goes back to the farmer.”
But Lewis added that when the Environmental Defense Fund worked with the giant pork producer Smithfield Foods to incorporate more wheat into its mix of feed, farmers responded by growing more.
“It took a clear market signal from Smithfield to take some land out of corn production and put in some wheat,” she said. “Those are probably areas where less the consumer and more the food companies will play a role in helping farmers diversify their crop rotations and adapt to climate change.”