Next to water, tea is the most popular and widely-consumed beverage in the world. Globally, six million acres are devoted to tea production. But the future of this multi-billion dollar crop is jeopardized by a host of climate-related changes that are making it harder to grow tea and altering the quality of the final product in teapots around the world.
India produces one-third of the world’s tea and about half of that comes from the tea estates of the Assam region in the northeast.
Yet Assam, typically categorized as sub-tropical, is increasingly resembling a fully tropical climate. According to data collected by the Tea Research Association, temperatures in Assam and Darjeeling have gone up by 2 degrees Celsius and rainfall has become erratic. While the total amount of rain in the region has not changed dramatically, the intensity of droughts and severe downpours has increased. The prolonged droughts are killing tea bushes and the intense rain events are causing erosion in tea plantations, terraced into hillsides.
“The weather is becoming very extreme and intense with much longer dry periods, or heavy downpours over many days and frequent hail and cyclonic storms,” Ashok Kumar of Goomtee Tea Estate told STIR, a tea and coffee industry publication. “The bushes are stressed, pest populations are increasing and monthly crop cycles are changing unpredictably.”
In Sri Lanka, another major tea-producing region, new pest invasions are one of the largest sources of loss on the plantations. Pests like the shot-hole borer and live-wood termite are moving up to altitudes where they have never been seen before. The insects stress the plant and the financial resources of tea growers attempting to control them. Average temperatures in Sri Lanka have already risen nearly 1 degree Celsius during the last century and are expected to keep rising. Tea is Sri Lanka’s second-largest export after labor, bringing in about $1.5 billion in 2012.
The value of Sri Lanka’s most expensive tea, a seasonal variety known as Uva tea, slumped by nearly 30 percent last year after early rains changed the distinct and highly prized flavor of the leaves.
A research team led by Tufts University, recently won a $931,000 grant from the National Science Foundation to study how climate change is affecting the flavor and health benefits of tea. The research, focused on three major tea-producing provinces in China will study how warmer winters and earlier, more intense rainy seasons are affecting the balance of chemical compounds found in tea leaves.