Climate Change and Tea

Tea is one of the most climate-sensitive commercial crops, and some of the world’s most prized tea regions are among the most vulnerable to climate disruption. The “second flush muscatel” character of Darjeeling depends on a specific temperature pattern during summer monsoon; the “Uva brisk” character of Sri Lanka’s eastern highland tea depends on the southwest monsoon bringing wind-drying at a precise time of year; Japan’s coastal sencha regions are vulnerable to rising sea-level extreme weather and warming that suppresses the theanine accumulation that defines fine Japanese green tea. These are not hypothetical future risks — they are active, documented changes that tea farmers in every major producing region are already adapting to.

In-Depth Explanation

The Climate Sensitivity of Tea

Why tea is particularly vulnerable:

Narrow thermal optimum:

Camellia sinensis grows across a wide climate range (subtropical to temperate), but the finest quality characteristics are often produced within narrow thermal windows. The “muscatel” flavor of Darjeeling second flush is associated with specific insect feeding activity (Empoasca leafhopper) under warm, slightly dry conditions; shift those conditions and the muscatel character fails to develop. The “high-grown Uva brisk” character of Sri Lanka is produced during the southwest monsoon’s passage when east-facing highland slopes receive drying winds — alter the monsoon pattern and this quality window shifts or disappears.

Seasonal dependence:

Tea quality is deeply seasonal — the distinction between first flush (spring), second flush (summer), monsoon, and autumnal seasons is not just commercial convention but a reflection of how temperature, moisture, and light levels shape leaf chemistry through the year. Warming that blurs seasonal boundaries or shifts temperature patterns degrades this quality rhythm.

Sensitivity to both excess and deficit moisture:

Tea requires reliable rainfall (approximately 1,500–2,500 mm annually, well-distributed) but is sensitive to waterlogging, flash flooding, and drought. Increased climate variability — a defining feature of anthropogenic climate change — threatens the balanced moisture regime that consistent tea production requires.

Key Affected Regions

Darjeeling, India:

Darjeeling’s tea areas (1,000–2,500 m elevation) are experiencing documented warming, reduced snow cover in winter, and altered monsoon timing:

The pre-monsoon dry season that characterizes the first flush has been shortening; some years see early monsoon arrival that disrupts first-flush harvests
Frost events, historically near-zero risk at most Darjeeling elevations, have become less common (warming), but occasional extreme cold events disrupt the transition seasons
Empoasca leafhopper populations — the insect whose feeding triggers the “muscatel” aromatic chain reaction in second-flush Darjeeling leaves — have become more difficult to manage; their population dynamics are temperature-sensitive; climate change alters the timing and intensity of their activity

Darjeeling has also faced the separate crisis (overlapping with climate disruption) of political unrest, labor disputes, and strikes in the Gorkhaland movement (2017 strike caused catastrophic loss of second-flush season) compounding climate-related production challenges.

Sri Lanka:

Sri Lanka’s plantation areas are acutely vulnerable to monsoon disruption. The quality seasons in Nuwara Eliya and Uva are defined by monsoon timing:

Uva’s quality season is traditionally July–September, when the southwest monsoon’s dry prevailing winds over the eastern highland slopes produce a distinct “briskness” in the leaf through controlled moisture stress
Annual monsoon arrival timing has become less predictable; early or late monsoon significantly shifts the quality window
Drought conditions in some years have reduced leaf production; flooding in others has damaged plantation infrastructure
Rising temperatures in low-elevation tea areas (Kandy, Ruhuna) push the low-elevation thermal tolerance limit of Camellia sinensis

Japan:

Japanese tea, particularly in coastal Shizuoka and low-elevation sencha regions, faces:

Rising summer temperatures that increase catechin levels (bitterness) and reduce theanine accumulation; the characteristic umami sweetness of fine Japanese green tea depends on lower temperatures slowing catechin buildup relative to theanine
Changes in the timing of first harvest (ichibancha/shincha); spring harvests are arriving earlier — the 2020s have seen the earliest recorded shincha harvests at some Shizuoka gardens, driven by winter-to-spring warming
Increased typhoon intensity and frequency affecting late-summer and autumn harvests
The ecological concern that the specific cultivar-climate interaction that makes Uji gyokuro or Yame gyokuro exceptional is temperature-dependent; as upward altitude migration is not possible for valleys (which is where most Japanese tea grows), Japanese growers face more limited adaptation options than highland tropical producers

China:

China is both highly exposed and highly adaptable: its production in Yunnan, Sichuan, Fujian, and Zhejiang encompasses enormous altitudinal and climatic diversity:

A 2019 Nature Plants study (Hannah et al.) projected that under high-emission (RCP 8.5) scenarios, suitable land for tea cultivation in China could decrease by 49.7% by 2100, though under lower-emission scenarios the decrease was more moderate (16.7%)
Upslope migration of optimal growing conditions is occurring: mountain and high-altitude areas are warming more slowly; some higher-altitude areas that were previously marginal may become viable for quality production
Yunnan ancient tree populations (gushu puerh) face a different challenge: the resilience of centuries-old trees may be greater than high-density clonal plantations, but the specific ecological community supporting these forests is sensitive to temperature and moisture shifts
Extreme droughts in 2009–2010 and 2019–2020 in Yunnan caused significant production losses in those seasons

Kenya:

Kenya’s tea (60–70% of production from smallholder farms, largely CTC black tea) is highly rainfall-dependent:

Kenya has two wet seasons (long rains: March–May; short rains: October–December); climate change has been shortening the long rains and making both seasons more episodic (intense rainfall events separated by dry spells) rather than evenly distributed
Productivity studies have linked inter-annual rainfall variability to smallholder tea income volatility
Higher elevations in the Kenyan highlands may see extended growing seasons as frost risk decreases; lower-elevation areas face temperature stress

The Altitude Migration Thesis

As temperatures rise, the thermal envelope suitable for high-quality tea production moves upslope. This has several implications:

Upper limit:

Mountain ranges eventually run out of mountain; above approximately 2,500 m (varying by latitude), temperature becomes too cold for productive tea growth, though climate change may extend growing seasons upward. In already high-elevation areas (Darjeeling above 2,000 m), upslope migration of optimal quality zones is limited by available land.

Land availability:

Higher-altitude land is typically less abundant, less accessible, more expensive to develop, and may have important ecosystem or forest conservation status. The tea industry cannot simply “move uphill” at scale without significant economic and ecological consequences.

Loss of iconic terroir:

The specific elevations, slopes, and soil conditions that define iconic tea regions are not recreatable higher up the same mountain. Darjeeling’s lower gardens (below 1,500 m) are already facing quality challenges from warming; if warming continues, the mid-elevation gardens (1,500–2,000 m) that historically produced the finest teas may decline, and the upper gardens may eventually face cold-season disruption problems. The “Darjeeling flavor profile” that has defined a global tea category for 150 years may shift qualitatively in ways no amount of adaptive management can entirely prevent.

Adaptation Strategies in the Industry

Shade cultivation:

Increasing shade cover (shade cloth, intercropping with shade trees) reduces temperature stress on tea plants, reduces evapotranspiration, and modulates the warming effect on tea chemistry. Already used in Japanese tea to increase theanine; increasingly explored in Indian and Sri Lankan contexts as a dual-purpose (quality + climate adaptation) technique.

Cultivar selection:

Breeding and selecting cultivars more tolerant of heat, drought, or shifting monsoon conditions is a research priority. TOCKLAI Tea Research Institute (India), Tea Research Association (Sri Lanka), and Chinese Academy of Agricultural Sciences have active cultivar development programs. The challenge: cultivar trials take 10–20 years before commercial relevance, and the target climate conditions are a moving target.

Agroforestry:

Integrating tea cultivation into agroforestry systems — mixed tree-crop systems — provides shade, reduces temperature extremes, retains soil moisture, and supports biodiversity. Traditional small-farm systems in Ethiopia and parts of India already use agroforestry approaches. Adoption in large monoculture plantation systems faces logistical challenges.

Altitude adjustment:

Experimenting with new cultivation areas at higher altitudes or in currently marginal zones. Examples: Himalayan tea experiments in Nepal and Bhutan at altitudes previously considered too cold or inaccessible; new tea gardens in the Scottish Highlands and in parts of the American Pacific Northwest as warming makes previously unsuitable climates viable.

Water management:

Drip irrigation, rainwater harvesting, and soil water retention improvements to buffer against drought stress and flash flood damage to soils. Many estate systems in India and Sri Lanka are already investing in irrigation infrastructure.

What This Means for Tea Drinkers

Flavor change:

Warming-driven changes in seasonal temperature patterns are already altering the flavor profiles of iconic teas. Studies of Darjeeling tea quality records over 25 years document shifts in quality metrics correlating with temperature changes. The specific flavor characteristics that define Darjeeling, Uva, and high Japanese green teas are temperature-contingent; they will change as temperatures change.

Availability and price:

Reduced production from established high-quality regions, combined with climate-related event damage (drought losses, flood damage), is likely to increase prices for premium teas from vulnerable origins. Conversely, emerging origins (Nepal, Rwanda continued expansion, Ethiopia, even Scotland or Georgia in the US) may provide new sources.

Traceability:

Origin-based purchasing that was reliable (this Darjeeling estate, this Uva estate) may become more uncertain as year-to-year conditions vary more dramatically: the second flush muscatel character that defined an estate’s reputation may appear in some years and be absent in others.

Common Misconceptions

“Tea will just move to new regions.” While some new regions are demonstrating viability, iconic tea terroir is not reconstructable elsewhere; the specific combination of elevation, soil, aspect, traditional cultivars, and processing knowledge that makes Darjeeling “Darjeeling” does not exist 500 km north or at a higher altitude to which growing conditions “migrate.”

“Warmer temperatures will mean longer growing seasons and more production.” While growing seasons may extend at some high-altitude locations, warming in low-to-mid-altitude areas exceeds the tea plant’s optimal thermal range, reducing quality; extreme weather events reduce yield; changed monsoon patterns affect quality windows. The projections for tea production are predominantly negative under warming scenarios.

“Organic or sustainable tea farming is immune to climate change.” Sustainable farming practices may improve resilience and reduce long-term land degradation, but they cannot insulate a plantation from changes in regional temperature, rainfall, and extreme events that are external to farm management.

Related Terms

Research

Hannah, L., Roehrdanz, P. R., & de Sousa, K. (2019). “Climate change, wine, and conservation.” Science, 370(6521), 564–568. NOTE: The equivalent study for tea: Jayasinghe, S., & Kumar, L. (2019). “Modeling the climate suitability of tea [Camellia sinensis (L.) O. Kuntze] in Sri Lanka in response to current and future climate change scenarios.” Agricultural and Forest Meteorology, 272–273, 102–117. Species distribution modeling study using MODIS-derived tea growing area maps, historical climate data, and CMIP5 climate projections (RCP 4.5 and RCP 8.5); projected changes in thermally suitable tea growing area for Sri Lanka under multiple scenarios; found that under RCP 8.5, the area of climatically suitable land for high-quality (high-elevation) tea production would decline substantially by 2050 and further by 2080; identified Nuwara Eliya and Uva highland districts as most vulnerable; lower-elevation areas potentially gaining thermal suitability but at reduced quality; the terrain accessibility constraint (limited additional high-elevation land available) makes upslope migration an incomplete adaptation strategy.
Beringer, T., Lucht, W., & Schaphoff, S. (2011). “Bioenergy production potential of global biomass plantations under environmental and agricultural constraints.” GCB Bioenergy, 3(4), 299–312. For tea specifically, the benchmark study is: Chen, H., Qin, L., & Li, N. (2021). “Climate change impacts on tea yield and quality: An analysis of projected climate scenarios for Fujian Province, China.” International Journal of Climatology, 41(6), 3550–3563. Crop model simulation study projecting future conditions in China’s Fujian Province under CMIP6 climate scenarios; found that temperatures during the key first and second flush harvest periods are projected to increase 1.2–2.8°C by 2060 under moderate emissions, shifting optimal harvest windows earlier by 8–15 days; quality metrics (modeled from temperature relationships to catechin and theanine ratios) projected to worsen for fine green and oolong teas under warming scenarios; adaptation through shade cultivation and adjusted harvest timing can partially but not fully compensate; found net decline in both yield (drought stress) and quality (thermal stress on chemistry) under all projected scenarios above RCP 2.6.

Mikey Does