Does Global Warming Make Rice Taste Better?

Salt, butter, and a dash of climate change.
November 26, 2021, 6:46am
japan, rice, climate change, global warming, politifood
A Japanese politician claimed rice tasted better because of global warming. Was he right? Photo: Shutterstock 

Steamed, scorched, pounded or fried, rice always delivers.

The adaptability of rice is in part what makes this staple the culinary cornerstone for half of humanity. Whether enjoyed with a beefy cut of steak, a rich curry, or just plain, it’s hard to imagine what else could improve on this steamy goodness.

But for former Japanese Prime Minister Taro Aso, the answer apparently lies with global warming. At a campaign rally last month, Aso claimed that rice on Hokkaido, the northernmost island of Japan, was tastier not because of the efforts of farmers, but due to climate change. 

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“It’s because it’s gotten warmer. When we talk about global warming, only negative things are written, but there are some good things,” the 81-year-old politician said in a speech on the island famous for its agricultural products and seafood.

His remarks provoked a backlash from the prefecture’s farmer union, which criticized Aso, now deputy prime minister, for diminishing the value of workers’ efforts. 

But there is a grain of truth to the claim that climate change impacts how our food tastes, sometimes favorably.

According to a paper published in April in the journal Science of The Total Environment, increased levels of carbon dioxide in the atmosphere do improve rice taste. After growing rice under enhanced levels of CO2, researchers from Jiangsu, China detected an increase in the volume of starch granules, where starch is stored in the grain. Given that starch makes rice sticky—a prized quality of Japanese rice—the paper’s researchers concluded taste was improved.

But scientists say that’s nothing to celebrate, and the effect of climate change on crop yields, among many other adverse consequences, is a far more serious concern.

“I think the bigger issue is that even if it tastes better, if you don't have very much rice, you’re not coming out ahead,” Pamela Ronald, a rice geneticist at the University of California, Davis, who is not affiliated with the study, told VICE World News. 

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If there’s too much water, as seen in Bangladesh, where climate change has been linked to increasingly frequent and severe flooding, rice crops come under oxygen stress and are unable to breathe, Ronald said. “And even if a rice plant grows quickly out of the water, then it will deplete in energy reserves and die,” she said. 

Scientific evidence also shows that increased levels of CO2, caused by global warming, meant a loss of nutritional properties in rice, said Jan Leach, a plant pathologist at Colorado State University. Studies suggest that elevated carbon reduces the amount of protein, zinc, iron and B vitamins per grain—all essential nutrients for humans. 

“This is possibly because they’re under stress, so instead of putting its energy into making the nutrients, it’s diverting those biochemical pathways,” Leach told VICE World News.

Climate change worsens extreme weather events, such as floods, heatwaves, droughts, and storms—things that are detrimental to rice crops.

“You’ll see an increased loss of rice production due to disease and due to drought stress, because there won’t be enough water to produce rice,” Leach said. Heat stress, too, leads to more disease and changes to the physical properties of vitamins and minerals.

In Japan, home to the sticky short-grain rice, the environmental impact of global warming has rice farmers fighting more weeds, which compete with rice in absorbing nutrients from the soil. 

To stop weeds from growing among his rice crops, rice farmer Shinichiro Higashi makes sure to submerge his paddies in just enough water to cover the grass. “That way, the grass can’t breathe and photosynthesize, which means they won’t grow as much,” he told VICE World News. 

But in addition to an increased number of weeds infiltrating his paddies in southern Japan’s Okayama Prefecture, Higashi said his harvests have been damaged by higher temperatures. “If it gets too hot, that affects the growth of rice and the crops just wilt,” he said. 

“Farmers try to adjust the amount of water, but weeds adapt to higher temperatures,” Higashi added. “The higher the temperature, the more new weeds will appear.”

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