What’s happening to my tea?


By Ellie Biggs
University of Southampton

In December 2015 John, Niladri and I attended the AGU annual fall meeting to present the preliminary findings of our research. We presented two posters; one focussed on the value of the tea landscape and the other on managing water resources for a climate-smart approach.


Niladri, Ellie and John at the climate-smart analysis poster

Our sessions were very engaging with a range of questions from those interested in the climate-yield analysis methods, to impacts on the livelihoods of tea stakeholders, to concern regarding a reduction in personal tea supplies.

We are now working on the last stages of data collection and finalising all our analyses, writing up our findings for publication in journals. We are also starting to develop a basic web-based decision support tool for the Tea Research Association to use in-line with their advisory services for member gardens. Training will be undertaken at TRA in February and wider dissemination of research will also occur through a final workshop and community fair with dates to be confirmed.

Enough Tea to Eat?


By John Duncan
University of Southampton

I have recently returned from a visit to Assam as part of a wider project assessing the impacts of climate change on tea plantations and the livelihoods of their workers. As highlighted in a Guardian report, tea plantation workers often suffer from the most distressing aspects of poverty beyond, though often consequential from, a lack of income. This Guardian report presented the challenging conditions under which tea plantation workers live and work, leaving families prey to human traffickers. To add to the vulnerabilities highlighted in this report, climate change is also adding to the burden placed on households as they strive to secure a livelihood. The impacts of climate change could have severe, negative impacts on the ability of tea plantation workers to enhance their well-being. Not only could climate change make it more difficult for tea plantation workers to lift themselves out of poverty in a sustainable manner it could make already precarious livelihoods more challenging.

Here, I offer some insights on how climate change could influence one of the key components of well-being; the ability to access sufficient and nutritious food.

Tea plantation workers in Assam.

Tea plantation workers in Assam.

Typically people go hungry not through there not being enough to eat but due to not having enough to eat, in other words, a result of barriers in accessing food. This view was articulated by Amartya Sen, the Nobel prize winning economist, when he outlined the various means of entitlement people have to access food. These entitlements typically include access to food via own production (subsistence), trade and purchases, labour, and transfers of food. To illustrate how climate change may exacerbate the vulnerability of tea plantation workers I speculate on how it may influence their ability and means to access food.

One of the most common methods of accessing food is through purchasing it in markets with earned money. This is contingent upon two factors: the ability to earn money and the presence and ability of markets to supply food at affordable prices. Tea plantation workers earn money through labouring on tea estates receiving a daily wage of less than 100 rupees (less than £1 a day). On its own this is a low wage; however, achieving this wage is dependent upon there being work available. Adverse climate change impacts to tea bushes could make them less productive and reducing the available work for tea plucking. This, could, in turn have knock-on effects on take home income and subsequent capacity to purchase food. On the other side, it is well documented that climate change will likely result in decreased crop yields (see chapter on Food Security and Food Production Systems). This could reduce supply and also increase the price of crops in markets. Under future climate change scenarios the same wage may result in less food brought home to feed the household.

Tea bushes recently attacked by pests; changing pest attack patterns is one of many potential impacts of climate change.

Tea bushes recently attacked by pests; changing pest attack patterns is one of many potential impacts of climate change.

Within the tea estates are several small rice fields. Tea plantation workers use the returns from these fields to supplement household food consumption. Numerous studies have documented the vulnerability of rice crops to projected climate change with risks spanning increased warming, shrinking day-night temperature ranges, precipitation variability and extreme heat events. Climate change has the potential to reduce the productivity of these small plots and at the very least increase the variability in returns from them. This will have obvious implications for household food security. Furthermore, the vulnerability of accessing food via these small plots may be amplified by other factors. The tenure and access rights of tea plantation workers to these plots may not be secure. If climate change reduces tea production this land may come under threat if estates expand to counteract productivity shortfalls. Also, tea plantation workers may not have access to agricultural extension and inputs such as new seeds and fertilisers to help them adapt to potential climate changes.

Small rice fields amongst the tea plantations in Assam.

Small rice fields amongst the tea plantations in Assam.

Finally, an important source of food for many poor and vulnerable households in India is subsidised rice via the Targeted Public Distribution Service. Tea plantation workers, holding a below poverty line (BPL) ration card, will be eligible for rice provisions from the state. Households obtain a BPL card through means testing surveys which happen at infrequent intervals. Initial conjecture suggests that based upon a rigid form of targeting food assistance may fail to come to the aid of households who fall victim to variable and short-term shortages of food resulting from direct (e.g. crop loss) or indirect (e.g. price increases) climate impacts.

It is clear that efforts to enhance the well-being of tea plantation workers needs to move beyond focusing on providing increased wages; a much broader, coordinated developmental approach is required. Using the example of food access, increased wages will yield more benefits when coordinated with favourable food markets, and access to productive resources such as land and seeds can be more valuable than increased wages by providing a buffer against market volatility. Furthermore, efforts to improve the livelihoods of workers and labourers in rural supply chains cannot be ignorant of the potential impacts of climate change.

How is climate affecting tea quality in China?


Answering the questions: Dr Selena Ahmed
Assistant Professor of Sustainable Food Systems
Food and Health Lab, Montana State University

Is climate change changing the taste of tea? Can producers and consumers perceive such changes? What are implications for farmer livelihoods and benefits we derive from tea as consumers? In this blog we find out more from a team of researchers working in China.

What’s so special about tea in China?
Tea is cultivated, processed and prepared in diverse ways in China. This diversity makes tea in China very special to me. China is regarded the motherland and centre of genetic diversity of tea with over 1,500 cultivars of the tea plant. It also grows in gorgeous systems from forests to shade-grown gardens to mixed plot fields.  I recently returned from a great field season in Yunnan Province of SW China where I sampled tea and interviewed farmers on climate effects on tea quality. As part of this fieldwork, I had the opportunity to eat fresh tea leaves harvested right off the plant – this is one of my favourite edibles. I also drank what seemed like infinite cups of spring tea that the tea farmers I was staying with harvested the same very week. This tea is characterised as full-bodied, complex, and bitter-sweet. What makes tea from these gardens in Yunnan discernible is the lingering sweet after taste that sticks like honey to the back of the throat in a sensation known in Chinese as gaan.

When is the best time to taste tea?
Anytime! With that said, spring tea harvest has come to be my favourite harvest. The spring harvest is also the most desirable harvest for tea entrepreneurs who make the trek out to the tea mountains from major cities of China in search of the young spring buds. The spring is when the buds and leaves are awakening from winter dormancy and also when the plants grow in relatively dry conditions that are suitable for tea quality. This spring, tea farmers in Yunnan Province shared that the tea harvest started a little earlier than in the past, while being a little later than in previous years. Tea farmers attribute this to changing climate factors as well as to land use change that impacts the local micro-climate.

What attributes determine the quality of tea?
Tea quality is determined by sensory characteristics and secondary metabolites that impart health benefits for human consumers. Secondary metabolites are compounds that are produced by plants for defense. Unlike animals that can move away from predators or uncomfortable environmental stress, plants are rooted and have evolved defense compounds to protect themselves from a range of environmental stress. Thus, tea quality is intricately linked to environmental, agrarian, and cultural factors. For example, the quality of tea harvested from an organic system is different than that harvested from a conventional system. Or that harvested from high altitudes varies from that at lower altitudes on the same mountain. I have been working in the motherland of the tea plant, SW China, since 2006 to examine how changing environmental and cultural factors impact tea quality. Here, indigenous communities cultivate tea in diverse systems including shade-grown agro-forests and mixed cropping. Leaves harvested from these systems differ in their quality.

So why is your research important?
Our research on climate effects on tea quality is important for several reasons. First, tea is the most consumed beverage in the world after water and thus any changes in tea quality from climate change would have consequences for a notable percentage of the world’s population. 
Second, in many instances, tea is produced by smallholder farmers as a primary source of income. Changes in income derived from tea that are driven by climatic shifts would thus impact these smallholder farmers. Farmers have continuously shared their perspectives regarding how climate factors and seasonality are major drivers of tea quality. Third, our project fills an important research need by focusing on climate effects on  crop quality. While it is well understood that more frequent and intense climate events in many areas are impacting crop yields, the impact on crop quality is less acknowledged. Knowledge on tea quality is critical for food systems that benefit both farmers and consumers through high-quality products. The framework developed and tested by our research may be applied to other speciality crops such as fruits, vegetables, wine, coffee, tea, maple syrup, and chocolate – all these products have unique secondary metabolite profiles that are notably impacted by the environment and management practices.

How do you measure the effect of climate on tea quality?
We are examining climate effects on tea quality through a multi-pronged approach involving field sampling of tea, controlled field and greenhouse experiments, laboratory analyses of biochemicals, sensory evaluation, consumer taste experiments, farmer surveys, and climate modelling. While data exists to create simulations on how tea yields in China may vary with forecasted climate models, there is a lack of information on how tea quality will vary. Consequently, we are collecting tea quality data through sampling of tea during different seasons that have distinct temperature and precipitation characteristics including the spring, summer and autumn season. We started this sampling in 2012 and plan to continue until 2016. In addition to our field site in Yunnan, we are also sampling in Zhejian and Fujian Provinces. At each location, we have a high elevation and a low elevation site. After the samples are harvested, they are used for various sensory experiments with tea farmers and connoisseurs, tea panels, and general western consumers. A portion of the samples are also sent to the lab where they are analysed for key aroma compounds that determine tea quality.

What have your results found so far?
Preliminary findings from our work have found that tea functional quality significantly varies with extreme weather events, which are becoming more frequent with climate change. Specifically, compared to an extreme spring drought, tea leaves grown during the monsoon at our study site in SW China were up to 50% higher in terms of growth parameters while concentrations of major compounds that determine tea functional quality were up to 50% lower. This suggests that changes in precipitation may have a dilution effect on tea quality or cause drought or water stress.

What does this mean for farmers?
A decrease in tea quality is associated with a decrease in tea prices and income derived from tea sales; which substantially impacts upon farmers’ livelihoods. Our findings validate farmer perceptions that precipitation impacts tea quality. Extrapolating findings from this study to long-term climate change suggests variability for farmers and the need to tap into farmers’ knowledge of management practices to mitigate climate risks in their agro-ecosystems for the sustainability of tea production.

What’s next?
We will continue sampling extreme seasonality variability for the next two years and we will carry out controlled experiments with tea plants in conditions that manipulative climate scenarios in tea-producing areas. This work will be coupled with interviews with farmers and consumers. Our studies with farmers involve determining behavioural responses of consumers to climate-induced changes in tea quality and yields and their implications on tea markets regionally and globally. At the farm-level, we are documenting how livelihood changes and tea farmer knowledge of climate effects on crop quality and yields feedback into the way farmers adapt their management and tea processing to adapt to climate conditions.

Can you predict whether the Chinese tea will taste different in the future?
Ultimately, we will input tea quality into a climate model to simulate future tea quality in different geographic areas on the basis of climate projections. We will also integrate findings from our lab analyses and interviews to use this evidence to develop management plans and policy suggestions for tea agro-ecosystems and processing, and ultimately facilitate societal action towards enhanced sustainability of food systems.


In addition to tea, Selena has begun to explore how climate is impacting other speciality crops. She recently received funding with another interdisciplinary team to explore climate effects on maple syrup quality and socio-ecological responses.

Selena’s research is funded by the USA National Science Foundation’s Dynamics of Coupled Natural and Human Systems (CNH) Program. The interdisciplinary team of scientists examining how climate effects tea quality includes Colin Orians (chemical ecologist), Albert Robbat (chemist), Tim Griffin (soil scientist), Rick Stepp (cultural anthropologist), Sean Cash (agricultural economist), Corene Matyas (climate scientist), Wenyan Han (tea and soil scientist), and Selena Ahmed (food systems scientist). Each of the team contributes different perspectives and methodologies from their fields to address this interdisciplinary issue. If you have any questions on their research please direct them to selena.ahmed@montana.edu.

For more info on their research see www.teaclimate.org

Dreamlining my way to the UK on my first trip abroad


By Sukanya Saikia
Tocklai Tea Research Institute

Being from Assam, I have seen tea gardens from my childhood when I used to visit my paternal house. I would be astonished by the scenic beauty of the tea growing regions; lush green in all directions. I used to be in awe that such huge estates could be managed so well. Tea is such an extremely important commodity for trade in India. Recently (a few months back), while I visited the tea-growing region of Upper Assam, I saw the saddening truth of the impact of climate change on tea. Although I am aware of climate change, I did not notice its impacts so closely until then. It sparked my interest in the subject; I felt a sense of duty towards the region where I have been born and brought up. So, when I came across a newspaper advertisement regarding a position of a research fellow at the Tocklai Tea Research Institute, a century old institute dedicated to R&D in tea, I applied for the position, got through the screening process and here I am!

A strong attack of looper (caterpillars) which eat the tea crop; due to reduced rainfall their presence has increased

A strong attack of looper (caterpillars) which eat the tea crop; due to reduced rainfall their presence has increased

I am Sukanya, a newly appointed research fellow and a proud member of our energetic and amazing research team. The brilliant collaborative project I get to work on is being undertaken jointly between the Tea Research Association and the University of Southampton (funded by UKIERI). I consider myself highly honoured to be able to work with such an eminent group of people. Since starting my position in May this year, I’ve had fantastic exposure to an elite group of people working on climate change and many other diverse fields, and as part of the project I get to exchange knowledge through visiting the UK. 26th July was the day of my first trip abroad. Of course, being my first international trip, it helped in adding to the excitement! On my journey I was accompanied by the Indian project coordinator, Dr. Niladri Gupta. He’s an excellent guide and knows so many facts about so many places! Before visiting a foreign land, I was a bit apprehensive for a few reasons: I was conscious of the accent difference between the two countries; I was wondering whether they would be welcoming enough; whether they would understand me; whether I would be able to understand them; would they be patient listeners. These fears dissolved instantly when I visited the University of Southampton and met the new people.

Ellie gave me a warm welcome at the University and Niladri showed me around the University campus. I was awestruck to see the huge library and all its facilities. Almost each and every leading journal is accessible; which is a big constraint in most of the R&D institutes in India. This is really helpful for the students and all the researchers. I have realised that life in UK is highly technical; yet very simple. Back in India, life still is more complex, even with tremendous manpower. I’m not saying that India is lacking in opportunities; India is full of doors waiting to be opened with various directions waiting to be explored. I feel it’s the attitude of certain individuals which need to be changed. The work culture in UK is very different – time is not a factor for them; they are dedicated to work. I respect their work culture. I feel sometimes it becomes a bit difficult here to achieve such a productive work ethic.

It was pleasantly warm when I visited the UK which made a nice break from the stifling humidity of Assam where it's currently monsoon season. Outside the Geography building, University of Southampton.

It was pleasantly warm when I visited the UK which made a nice break from the stifling humidity of Assam where it’s currently monsoon season. Outside the Geography building, University of Southampton.

Anyway, the UK research team provided an enthusiastic welcome and a thoroughly engaging environment for me to share their knowledge and experience. During our meetings we discussed climate change issues and how we can identify potential solutions to mitigate its impact on tea production and assist the transition of the tea gardens to adopt climate-smart agriculture. It was a highly productive two weeks and I learnt a great deal. Apart from this project, other prospects of future work were also discussed. It’s superb to see how minds work and come up with such brilliant ideas. How these ideas could be executed and transformed to reality is just a few steps away. After all, small steps lead to big milestones!

Visiting a tea shop in Winchester. They were selling 2nd flush Harmutty tea from Assam

Visiting a tea shop in Winchester. They were selling 2nd flush Harmutty tea from Assam

Besides the enlightenment of knowledge, I saw some English countryside as well as historic and beautiful places during my stay; Winchester, wild horses in New Forest, the Red Arrows on the Isle of Wight, cruise liners at Southampton docks, and many sites around the historic city of Southampton and some of London during the weekends. Even when we visited these places the subject of tea and climate still managed to creep in; we stopped in a Whittard tea shop in Winchester and interacted with the shop owner about her views on the tea trade; we reflected upon the warm weather the UK was currently experiencing and the science behind why this might be; we discussed about the newly developed English tea estate at Tregothnan in Cornwall. This was all impromptu relative to the situation and quite fun!

Me with the two project PIs next to the beautiful River Itchen in Winchester

Me with the two project PIs next to the beautiful River Itchen (a chalk stream) in Winchester

Exchange programs such as UKIERI provide much essential opportunities to enhance and broaden the thinking, understanding and seeing the world with different perspectives. This two-week trip has been a life-changing experience for me. Thanks a lot to Ellie, John, Jenny, Andy, Emma, Pete and Niladri for showing me around this intoxicatingly beautiful country of the United Kingdom; and thank you so much for the marvellous food which my taste buds got to experience. For now, we are progressing with the research and having frequent discussions over Skype, but I cannot wait to return next year to see everyone again, meet new people, carry on with our excellent work and come up with many new ideas for how science can help my home state of Assam cope with the climate impacts of the future.

The next steps… As part of my position as a research fellow, I have the opportunity to enhance my skills through undertaking training. I have already completed an online course on An Introduction to the Science of Climate and Climate Change conducted by the University of Oxford, Met Office Hadley Centre and Natural Environment Research Council in UK. Next, I am preparing to undergo training in MATLAB which will further my skills in coding to enhance the development of models to analyse climate and tea yield data.

From the tea estates of Malawi… to those of North-East India


By Jenny Willbourn
MSc Applied GIS and Remote Sensing
2013-2014 University of Southampton

In 2008 I wanted an adventure, I ended up in the middle of nowhere, forty minutes walk from a road. I was on my gap year in Mulanje, southern Malawi where I lived on a tea plantation and taught at the local school for 8 months. Little did I know at the time that tea would shape my time in academia. Three years later I jumped at an opportunity to go back to Malawi and secured my place as Lujeri Tea Estates summer GIS consultant  – a job that ultimately lead me to the University of Southampton to study GIS and RS.

Figure 1 – A view of Mulanje tea, tropical forest and Mt Mulanje.

A view of Mulanje tea, tropical forest and Mt Mulanje.

I extended my stay in Mulanje to collect data for my dissertation which questioned to what extent people’s personal accounts can be combined with climatic change data and to what extent the datasets are looking at the same thing. I concluded that the local Mulanje people, whose lives were intricately tied to the wellbeing of the tea estates and to success of local subsistence agricultural, were certain that climate change was occurring and negatively affecting their livelihoods. However, the climatic data, in general, did not support the views of the local people and hence many of the increasing struggles they were facing were as a result of socio-economic changes, not exclusively climate.

Two years later I was invited to participate in UKIERI exchange programme for a project on climate-smarting tea in Assam, India. This was rather serendipitous as no one was aware of my tea background. I again jumped at the opportunity and assisted in the collection of GPS ground control points across several tea plantations in Assam.

Figure 2 – Assam tea and shade trees. The vines on the shade trees produce black pepper corns.

Assam tea and shade trees. The vines on the shade trees produce black pepper corns.

It was my first trip to India and needless to say it was fascinating – not only from a socio-cultural point of view, but being able to compare the tea management systems between Mulanje and Assam. The tea grown in Mulanje has a smaller leaf and plucking table (the height the bush is pruned to), it also tended to be very well maintained and very closely planted. Importantly much of it is irrigated. In contrast, the tea in Assam is slightly larger, higher and not all the tea estates have the resources to maintain the bushes so well. There is no irrigation. It is important to note, however, that the scale of production in Assam is vast compared to Mulanje. The other visible difference is that the majority of tea in Assam is grown in shade under trees to reduce the ambient temperature, but not in Mulanje. Both regions rely on low-skilled low-paid workers for plucking the tea but both are now looking at mechanisation, although in very different ways. If (or when) mechanisation takes off this will significantly alter the socio-economic relationships between tea plantations and the local people.

The climate setting is also vastly different. Tea, actually a tree not a bush, originated from the Assam region where it is now grown on the huge flat flood plain of the Brahmaputra river, whereas tea was introduced to Mulanje in the colonial period and is able to grow due to Mount Mulanje, a 3000m granite inselberg, that increases the rainfall and lowers the temperature of the local area. It is currently unclear how tea will respond to future climatic changes and how this will affect the people who rely on it.

Figure 3 – An individual tea bush. The top bright green leaves, normally two and a bud, are plucked to produce tea.

An individual tea bush. The top bright green leaves, normally two and a bud, are plucked to produce tea.

During my time in India I stayed in the Tea Research Institute of India and having also met with the Tea Research Association in Malawi in 2012, I was quite surprised to learn that there is not greater collaboration between the various tea research institutions across the world. Sadly, some of these institutions do not have the funding and resources they need, which highlights the importance of cross-country/cross-institutional research such as the UKIERI project.

I also needed to tie in my time in Assam with my MSc research project. Aware of the sensitivity of tea to climate and keen to keep my project quantitative I was drawn towards to the emerging concept of physical water productivity – the amount of yield produced per unit of water consumed. In the context of a changing climate, this concept allows us to assess:

  • Where tea is grown with the least water consumption;
  • What the management practises in high water productivity areas are;
  • What locations have scope for improvements;
  • What locations are most at risk in the future.

This is particularly important as water resources are likely to be under increasing strain as the global temperature rises, precipitation patterns and quantities change, and the world population continues to expand therefore increasing demand.

Based on the work of Zwart et al, 2010 I utilised and adapted the WATPRO model which negates the need for a vast number of agro-climatic variables normally needed for water productivity modelling and replaces them with inputs available from satellite remote sensing data. The aim was to create an average water productivity baseline from which changes can be measured in the future in Mulanje and Assam.

Figure 4 – Mulanje tea estates estimated water productivity baseline 2002-2012.

Mulanje tea estates estimated water productivity (WP) baseline 2002-2012.

I am currently in the stage of processing the results and it is clear that the model has produced sensible results for Mulanje, although it has most likely a slight underestimation. It is also clear that the management of tea in Assam (the use of shade trees in particular) has significantly reduced the viability of the model in Assam. Although there is not yet full validation data for model work such as this, such models are likely to play an increasingly important role in agri-management especially in locations where money, time, knowledge and facilities limit what is known about the tea crop. In the long-term this increases the potential for precision agricultural to ultimately produce higher yields with less inputs.

I’m not sure where my next adventure will take me, but the betting is definitely on somewhere that grows tea!