The recent heatwave in Malawi has led to consecutive dayswith very high temperatures. This is exactly the scenario that tea growersfear. Over the last 18 months, our work with smallholder farmers andlarge-scale tea producers in the southern districts of Mulanje and Thyoloidentified the risk of heat scorch to tea bushes as a major concern.
Unprecedented heat wave
According to the Department of Climate Change and MeteorologicalServices, the Mimosa weather station (in Mulanje) recorded temperatures exceeding35°C, and as high as 40°C, during a 10 day period in late October. The resultof the heatwave has been that the leaves of tea bushes – which are what isharvested – turned brown and shrivelled.
An employee of a tea estate with over 19years of experience in the industry said that it is not unusual to come acrossscorched leaves at this time in the season, and it can be reversed if the hottemperatures are rapidly followed by rains. However, rains have still notstarted in Mulanje and Thyolo and the extent of scorching is going toinevitably reduce this year’s tea harvest.
Anticipating a “newnormal”
The current heatwave may have been unprecedented and unexpected, butclimate projections show that this occurrence will become more common in thefuture. Whilst currently there are around 40 days per year with temperaturesexceeding 35°C, this is likely to become 50 to 100 days by the 2050s inMulanje. Stakeholders in Malawi indicated that the threshold temperature for aconsecutive 5-day period (heat stress threshold) that affects growth rate is35°C. There is a real likelihood that the conditions witnessed last month willbecome a more regular occurrence, and the breaching of this threshold wouldrisk future tea yields.
Growing tea is important in Malawi. It is in the top 3 contributors toGDP through export earnings. It also provides employment, contributing to thelivelihoods of many men and women. There are 18,500 smallholder farmers alone,and many more employed as seasonal farm workers or tea pickers. Ensuring teaproduction is sustainable in these conditions – and continues to contribute tothe economy and create employment for Malawians – requires planning that takesinto account climate risk.
Improving climateinformation tailored to tea farmers
The average lifespan of a tea bush is over 60 years. That means thatdecisions taken now will have a long lifespan and affect production levels intothe future. With this in mind, smallholder farmers, commercial tea estates, andthe Tea Research Foundation of Central Africa have been working with scientistsfrom the CI4Tea project (as part of the Future ClimateFor Africaprogramme) to better understand and communicate what thefuture climate could look like, and help tea growers think about the adaptationdecisions that they need to take.
The Future Climate For Africa (FCFA) programmeaims to generate fundamentally new climate science focused on Africa, and toensure that this science has an impact on human development across thecontinent. As well as the tea sector, FCFA is working with national governmentsand cities to inform planning relating to water, agriculture, energy, floodrisk, and sanitation.
Supporting adaptation in the tea sector hasbeen aided by the availability of new, high-resolution climate projections froman innovative model – CP4-Africa. Global Climate Models are usually better atprojecting temperature than rainfall. However, in contrast to these models,CP4-Africa simulates convection processes, and therefore offers potential tobetter represent rainfall that is influenced by topography and relief. This isparticularly relevant in southern Malawi, where tea is grown along the lowerslopes of Mount Mulanje.
Availability of better climate information is essential to manage risk and enable adaptation to climate change. Local scale future climate projections show that more warming is projected for sites at Mulanje, whereas in Thyolo there will be an increase in the number of consecutive dry days. Understanding the range of potential future climatic changes can help tea growers choose adaptation strategies that take changing future risks into account, such as the development of climate smart tea cultivars, efficient irrigation systems, and improved farm management strategies.
Watch the FCFA documentary Climate Change and Tea: Challenges for Malawi and Kenya
This article was written by Neha Mittal, Katharine Vincent, and Andy Dougill.