Tea plants around the world are getting too much rain, says Eater. The excessive precipitation is lowering the number of secondary metabolites they produce—the chemicals responsible for caffeine, antioxidants and flavor.
“When it’s really wet, the [tea] plant doesn’t have the ecological cue to make [certain] compounds, and [what they do make gets] diluted,” says Selena Ahmed, an assistant professor at the University of Montana, who, in collaboration with researchers at Tufts University, has been studying the effects of climate change on tea.
“While size and the weight of the tea leaves may nearly double because of the rain, the plant’s major phytochemicals will decrease to about half,” says Eater. Damage is already being seen in the world’s top tea-producing sites, including Japan, China’s Yunnan Province, and Assam and Darjeeling in India.
All tea—white, black, oolong and green—comes from the same plant: Camellia sinensis. How growers process and ferment tea is what determines the type. But with heavy monsoons bruising tea plants, farmers are increasingly opting to produce oolong and black teas, which have longer fermentation periods that can help cover up the taste of subpar leaves.
Apart from heavier rains, higher and less consistent temperatures are also taking a toll. Plants are budding sooner than usual, putting them at higher risk of a spring frost.
Ahmed says farmers can protect their tea from climate change by growing plants from seed (to encourage stronger roots) in diverse agro-ecological systems, rather than monocultures. “Traditionally in southwestern China, tea plants were grown in a forest ecosystem,” she explains. “This multistoried structure, or agroforest, helped manage pests and diseases.” Agroforests are better able to withstand changes in the weather and heavy rainfall, too. Studies have also shown that organic tea produces more phytochemicals, making them both taste better and better able to ward off pests.