Most of us won't soon forget that disconcerting moment last spring when grocery store shelves were suddenly bare where the flour, pasta, and other staples should have been. The news told of farmers dumping milk — nearly 4 million gallons a day, by one account — smashing eggs, and euthanizing chickens that they couldn't get to market. Crops worth billions of dollars were wasted, some rotting in the field, as restaurants and other food service businesses, shuttered by lockdowns, stopped buying.

The problem was short-lived, fortunately, as growers pivoted to new buyers, shippers and packers adapted, exports resumed, and the food system — the complex web of players that move food from farm to fork — came back to life. "Overall, the food system has been quite resilient," says Johan Swinnen, director general of the International Food Policy Research Institute, a leading international think tank. "It's hard to imagine a bigger shock than we've had now. And despite that, if you look at the rich countries, even countries like China, the food supply has not been a problem almost anywhere."

The food system didn't break, but it did flinch — and the public noticed. "People experienced for the first time that you can't take for granted that whenever you need something, it's there on the market shelf," says Matin Qaim, an agricultural economist at the University of Göttingen in Germany.

For Qaim and other experts, the experience with COVID-19 can be viewed as a kind of stress test for our global food system, highlighting its strengths as well as its weak points. It's helping them focus on what needs to change to build a truly resilient system. And we're likely to need that resilience soon, they warn, as climate change makes droughts, floods, windstorms, and other extreme events more common. Those challenges, they say, will require changes in where and how we grow food, and in the way society structures the supply chains that keep food, fertilizer, and other commodities moving around the world.

The next crisis could well be worse. After all, global harvests have been mostly unaffected by COVID-19, and food prices didn't rise dramatically in 2020 (though they have been edging up in early 2021). When lockdowns shuttered restaurants, school cafeterias, and workplace eateries — the food service industry that formerly accounted for about half the food consumed — suppliers pivoted within a few weeks, finding ways to repackage their products into smaller portions for retail sale.

But we may not be so lucky next time. "It's not unlikely that sometime over the next decade or two we will have a significantly worse drought," says Tim Benton, a food systems researcher at Chatham House, a U.K.-based think tank. Such a drought or some other equally severe weather event, or a major crop disease outbreak, could decrease global food production by 10 or 15 percent, he says, leading to skyrocketing food prices, hunger and widespread panic. "That is orders of magnitude worse than COVID."

Read the rest of the article at Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.