By the year 2050, the world’s agricultural landscape could look very different than it looks now.
Around 10 billion people will need to be fed, up from the nearly 8 billion on Earth today, and climate change will alter where that food comes from. Already, warming temperatures are allowing tropical foods to thrive in growing regions further north, where they haven’t before—citrus, for example, is being grown in Georgia and avocados on Italy’s island of Sicily.
“Take your computer and type in climate change followed by your favorite food, and you will, half the time, get a climate change story affecting your favorite food,” says Michael Hoffman, an author of the recently published book Our Changing Menu.
A new study published in the journal PLOS One models how growing conditions for three popular foods—coffee, cashews, and avocados—will change in the next 30 years, and found a complex landscape of winners and losers.
Of the three crops, coffee will be hit hardest by warming: The study model foresees an overall decline by 2050 in the number of regions where it could grow. For cashews and avocados, results were more complicated. Certain growing regions would experience declines in those crops while others, such as the southern United States, would likely find more land better suited to tropical food crops like cashews and avocados.
This research expands on previous studies that already documented the detrimental effect climate change will have on coffee beans. It offers more evidence of decline by looking at a wider range of factors, such as how the PH and texture of soil could change with more rainfall. It’s also the first global look at how climate change will affect cashew- and avocado-growing regions.
“Certainly it’s possible to adapt in many places” to compensate for shifting conditions, says study author Roman Grüter, an environmental scientist at the Zurich University of Applied Sciences in Switzerland. Scientists and farmers are already experimenting with crossbreeding certain crops to create hardier traits that can better survive climate change. In some regions, as in the state of Georgia and Sicily, entirely new species of crops are being planted. But the study cautions that may not be enough.
“At some point it might not be possible for a crop to grow anymore” in its traditional region, says Grüter.
Modeling the future
Studies modeling climate change’s impact on agriculture have often looked at lucrative crops such as soy, corn, and wheat. But Grüter says the kinds of foods grown on small-scale farms have been less studied, though they’ll be a crucial piece of the puzzle when preparing the global food supply for climate change. According to the Food and Agriculture Organization, small farms produce a third of the world’s food. And the three crops analyzed in the study are also important to understand because unlike corn or wheat, they’re planted years in advance of harvests—meaning decisions about what types of crops to grow are based on assumptions about future growing conditions such as temperatures and rainfall patterns.
The world has already warmed by 1.1 degrees Celsius (2 degrees Fahrenheit), causing more heat stress in plants and an increase in the severity of natural disasters. By 2100, the world could heat up by 3°C (5.5°F). Looking at 14 different models, the researchers predicted how global conditions would change under three different climate scenarios: a drastic reduction in greenhouse gas emissions that limits warming to 1.6°C (2.9°F), a moderate reduction that limits warming to 2.4°C (4.3°F), and a worst-case scenario where warming exceeds 4°C (over 7°F).
The study results were characterized by three buckets of “suitability”—high suitability being where a certain crop would produce the highest yield without relying on irrigation and fertilizers.
Of the three crops, coffee was by far the most affected by future climate. By 2050, in all three climate scenarios, the number of regions most highly suited for growing coffee declined by 50 percent. The decline was primarily the result of increasing annual temperatures in coffee-producing countries like Brazil, Vietnam, Indonesia, and Colombia.
For cashews, declines varied widely. Some declines were drastic. In West Africa’s Benin, high annual temperatures were projected to drive a nearly 55 percent decline in land highly suited for growing cashews, even when emissions were slashed. Other countries saw just single digit declines if nothing further were done to mitigate climate change. Overall, however, land suitable for growing cashews was projected to increase by 17 percent around the world, thanks to increasingly warm winters in higher and lower latitudes like the U.S., Argentina, and Australia.
Avocados, which evolved to grow in rainforests, had similarly varied results, and saw changes to where they can grow based largely on shifts in precipitation. Warmer climates can hold more moisture, leading to more rainfall, and warming regions were projected to produce more rain by 2050. Regions best suited for growing avocados were estimated to decline by 14 to 41 percent around the world in countries such as the Dominican Republic and Indonesia, but regions moderately suited for growing the fruit increased by 12 to 20 percent.
In Mexico, currently the top producer of the fruit, suitable avocado-growing conditions were expected to increase by anywhere from 66 to 87 percent, based on emissions emitted by 2050.
The study’s results are consistent with what University of Georgia agriculture climatologist Pam Knox has seen in the Peach State. She says food growers have been experimenting with new foods now suited to the region’s warming winter climate.
“Farmers are already taking advantage of this in the southeastern U.S. by trying out new crops like olives and satsumas,” she says in an email.
Adapting foods for the future
What might the varied study results mean for our global food supply in 2050?
How climate change will affect future food security needs more research, Hoffman says. For example, he says, climate change increases the amount and kind of pests that attack crops. The natural assumption may be that those crops will decline, but what if the number of the pests’ predators also increases? As some growing regions expand while others shrink, it’s challenging to predict the fates of specific food items.
What is clear, says Hoffman, who was former executive director at the Cornell Institute for Climate Smart Solutions, is that the decline of a particular crop can have a devastating impact on the local level—“like a giant factory moving out of town.”
To help communities weather this change, the study says food growers will need to adapt in a variety of ways, from using cover crops to keep soil healthy to breeding more climate-hardy varieties, such as coffee that can tolerate higher temperatures.
But as a solution, breeding has limitations: It can take years to perfect, and plant breeders may not be able to keep up with the pace of climate change, says Charles Brummer, director of the plant breeding center at the University of California, Davis. Even the most heat-tolerant plants may not be able to successfully produce if heat waves become more severe and more frequent.
By predicting decades in advance how agriculture will change, scientists can help farmers know what to expect, and can advise policy makers on how to encourage farmers to use more efficient growing methods like cover crops to prevent erosion or planting new crops when needed.
“It’s crucial for food and nutrition security to model such changes and their impacts on agriculture,” says Grüter. “We model now mainly cash crops, but avocado is also an important, nutritious crop.”