India is the world's second-largest tea producer, growing approximately 1.3 billion kilograms annually across roughly 640,000 hectares of tea gardens in Assam, West Bengal, Nilgiris, Kerala, and several northeast states. The tea in your morning chai almost certainly came from one of these regions.
Climate change is now measurably threatening all of them — and the consequences are beginning to show up in the cup.
What Is Happening to Darjeeling
Darjeeling tea occupies a unique position in the global tea market. The Darjeeling First Flush — the season's first harvest, plucked in March and April when the tea bushes wake from winter dormancy — is priced higher per kilogram than most wines. It cannot be replicated anywhere else on Earth; its flavour is the product of Darjeeling's precise altitude (600-2,000 metres), fog, and cool temperatures.
Those temperatures are changing. Research published by the Tea Research Association and supported by data from the Indian Meteorological Department shows that Darjeeling has warmed by approximately 1.2°C since the 1950s, with nighttime temperatures rising faster than daytime ones. The fog that protects the gardens and shapes the tea's character has become less reliable.
The direct impact on production is documented. Darjeeling's annual output peaked at around 11,000 tonnes in the early 1990s. By the early 2020s, it had declined to approximately 6,000-7,000 tonnes — a drop of more than 40% — with climate disruption, labour shortages, and shifting monsoon patterns all contributing. The Tea Board of India has acknowledged the decline in official communications.
The First Flush season — historically reliable from March 1st — has shifted. In warmer years, early buds emerge in February, but with less of the flavour complexity that makes Darjeeling tea distinctive. The muscatel character (the floral, wine-like note that defines great Darjeeling) is a stress response in the tea plant to specific temperature conditions; warmer, more stable conditions reduce the stress and with it, the flavour.
What Is Happening to Assam
Assam is India's largest tea-producing region, accounting for roughly 52% of national output. It grows primarily CTC (crush-tear-curl) black tea — the full-bodied, malty tea that is the base of most Indian masala chai.
Assam's main climate threats are different from Darjeeling's:
Extreme flooding. The Brahmaputra river system floods every monsoon season, but intensity has increased. The 2022 and 2023 Assam floods were among the most destructive in recorded history. According to the Assam government's disaster management authority, over 5 million people were displaced in each of those years. Tea gardens in the Brahmaputra valley have faced inundation, erosion, and soil damage that takes seasons to recover from.
Drought in off-seasons. Paradoxically, Assam is also experiencing more intense dry spells between monsoon cycles. Tea plants need consistent moisture; extended dry periods stress the bushes, reduce yield, and alter flavour profiles. The Tea Board of India's 2023 report noted yield reductions of 8-12% attributable to rainfall irregularity across multiple Assam districts.
Temperature rise in growing months. Assam's tea quality depends on moderate temperatures during the growing season (April-November). A 2021 study by the International Centre for Integrated Mountain Development (ICIMOD) projected that if current warming trajectories continue, Assam could lose 20-40% of its suitable tea-growing area by 2050.
The Nilgiris and Beyond
The Nilgiri hills of Tamil Nadu and Kerala — the "Blue Mountains" that produce much of India's orthodox tea and the base for many South Indian chai blends — are facing similar pressures. A 2020 study in PLOS ONE modelling Indian tea yields under climate change scenarios found the Nilgiris among the most vulnerable regions, with projected yield decreases of 15-25% by mid-century under moderate emission scenarios.
What the Industry Is Doing
The Tea Research Association of India has been developing climate-resilient tea cultivars since the 2010s. Several estates in Assam and Darjeeling have shifted toward more shade trees (which moderate temperature), drip irrigation (which reduces water dependence), and organic certification (which is proving more climate-resilient in several studies).
Some Darjeeling estates have pivoted toward specialty production — fewer kilograms at higher prices, leaning into the rarity that climate change is, grimly, accelerating. A shrinking first flush becomes more valuable per gram as it becomes harder to find.
What It Means for Your Cup
In the near term: prices for quality Darjeeling and premium Assam teas will continue to rise. The flavour character of Darjeeling First Flush will become more variable year on year. Some estates will shift to less temperature-sensitive tea varieties that lack the complexity of traditional cultivars.
In the longer term — beyond 2040, under pessimistic scenarios — the geography of Indian tea production may shift northward and upward in altitude, following the temperature bands that the tea plant requires.
This is not hypothetical. The shift has already begun.
Data in this article draws from the Tea Board of India, the Tea Research Association, the Indian Meteorological Department, and peer-reviewed studies cited in-text.