High hills and abundant rainfall make the north-eastern state of Assam an ideal place to grow tea, with 850 gardens over 320,000 hectares (593,000 acres) producing the majority of the country's harvest. But in the last 60 years, rainfall has fallen by more than a fifth and minimum temperature has risen by a degree to 19.5C.
"This is clearly climate change, and it is bound to have major impact on the tea industry," said Debakanta Handique, a climate scientist in Assam.
The Tea Board of India said it had recorded a steady decline in tea production in recent years. In 2007, Assam produced 512,000 tons of tea. By 2008 this had declined to 487,000 tons, with estimated production in 2009 down again to 445,000. A further decrease is expected this year.
Mridul Hazarika, director of Tocklai Tea Research, the oldest tea research station in the world, said rainfall and minimum temperature were two of the most important factors affecting both quality and quantity of harvests.
"The decline has been taking place although there has been an increase in the area of tea cultivation as new gardens have come up, and many gardens have added new areas for tea plantation. This is an indication of the seriousness of the threat," said Hazarika. Efficient rainwater harvesting and new breeds of tea plants were needed to reverse the trend.
"Changes have already been observed in the flavor, but it is not possible to blame only climate change for this," he said. "Other factors like the fertilizers used and cultivation methods might also be partly responsible."The changing taste of Assam tea is a serious concern for growers. Sudipta Nayan Goswami, an Assam-based planter, said subtle changes had already been observed: "The flavor has changed from what it was before. The creamy and strong flavor is no more."
"There is a huge demand for Assam tea abroad, and this is due to its strong, bright flavor. The changes will sharply hamper the demand for this variety of tea abroad."
The Guardian,"Climate change leaves Assam tea growers in hot water", accessed December 28, 2010