People’s livelihoods depend on the coffee industry, but climate change is changing weather patterns, introducing or increasing pests and diseases and disrupting where the plants can be grown
One July Sunday morning, I woke up to a shocking CNN headline stating: “Melting polar ice is changing the way Earth spins and making days longer.”
Global warming and climate change have led Mother Earth to global shocks and uncertainties.
The world is undergoing unprecedented, diverse impacts as a result of climate change, creating environmental calamities that result in food insecurity, death, migration of refugees, diseases and volatility in agro-productivity and production.
Climate change has not spared the East African region, with floods in Kenya, the rising levels of Lake Victoria, the drought in northern Uganda and volatile changes in the rainy seasons in coffee-growing areas.
We have criminally underrated how global warming affects coffee production, which supports livelihoods and economies.
As a beneficiary of the coffee value-chain system, where my father earned the money to pay our school tuition and domestic expenses, let me enlighten you about how the impacts of climate change are reshaping the coffee industry.
Uganda is the second-largest coffee producer in Africa, the fourth-largest Robusta-producing country, and the 10th-largest coffee-producing country in the world.
In the 2022-23 financial year, coffee generated export revenue of $826 million, according to the Uganda Coffee Development Authority.
Two varieties are grown in Uganda, Arabica (Cof fea arabica) and Robusta (C. canephora), comprising 20% and 80% of the total coffee production, respectively, the authority’s 2019 handbook noted.
Arabica is grown in the highland areas on the slopes of Mount Elgon in the east, and Mount Rwenzori and Mount Muhabura in the south-western and north-western regions, respectively.
Robusta is grown in the central, eastern, mid-north, West Nile, western and south-western regions.
About 1.7 million households and more than nine million Ugandans benefit from the coffee value chain.
The livelihoods of farmers are directly tied to the success of their coffee crops. Production relies on smallholder farmers, a population group that has been identified as the most vulnerable to climate change.
Ugandan coffee is under threat because the country is ranked one of the most vulnerable to climate change globally as well as one of the least prepared to deal with the effects.
Over the past three decades, coffee-producing areas in Uganda have become drier and hotter, with annual temperatures predicted to rise by 1°C to 1.3°C by the 2060s. In addition, the distribution of rain is becoming more variable.
Floods are anticipated to increase in coffee-growing regions such as Elgon, Buganda and Kigezi.
These can cause changes in pests and diseases, soil erosion and irregular flowering.
Broadly, if temperatures increase, areas suitable for growing coffee will be at higher altitudes and much of the current coffee-growing areas will become unsuitable for the crop, according to an Oxfam article titled The Impact of Climate Change on Coffee in Uganda: Lessons from a case study in the Rwenzori Mountains, by Laurence Jassogne, Peter Läderach and Piet van Asten.
Due to climate change, some areas will become more suitable for coffee growing but it will have to compete with other crops and national nature reserves. And this could result in conflicts over land between coffee producers and nature conservation.
In the areas that will become less suited to growing coffee, adaptation strategies will need to be developed to sustain its production, according to Jassogne et al.
In addition, climate change is affecting the flowering and bean-filling stages of coffee, while the increased temperatures have accelerated ripening.
Prolonged droughts in the elephant belt and northern Uganda, among other areas, are causing plants to become weak, wilt and an increase in flowers falling off prematurely.
In the Bugishu and Buganda region the increase in evapotranspiration, the processes by which water moves from the land surface to the atmosphere via evaporation and transpiration, has pushed up water requirements, which is a problem because most farmers rely on rain, which has become increasingly unpredictable, for irrigation of their crops.
The erratic rainfall, caused by changing weather patterns, causes the coffee plants to flower more often, which means more frequent harvests, increasing labour costs.
Where the rainy season has become longer, this has affected flowering, fruit set because of reduced temperatures.
Climate change will also affect the spectrum of pests and diseases. For example, the coffee white-stem borer, which currently affects Arabica coffee grown at low altitudes, is anticipated to become a major pest at higher altitudes.
Coffee leaf rust also is becoming more common at high altitudes.
Studies show that climate change and habitat loss will increase the extinction of bird species that help to control pests, increasing the distribution of pests such as the coffee berry borer.
Shifts in precipitation influence flowering, affecting the diversity of visiting bee species and fruit sets. Coffee farms could experience pollinator deficits in the future.
The average number of bees is expected to decline by 8% to 18% in coffee-suitable regions.
All of this will have an effect on yields and quality.
A yield loss of 116kg a hectare of green coffee has been reported for every degree of increase in temperature, according to a research article by Allesandro Craparo et al, titled Coffea Arabica Yields Decline in Tanzania Due to Climate Change: Global Implications.
Another complication is the effect of higher altitude on growing coffee.
“A study suggested that the quality of coffee beans may be adversely affected by increasing altitude; by 2050, the overall capacity to produce acidic and flavourful coffee beans will decline,” write Jeremy Haggar and Kathleen Schepp in the International Journal of Forestry and Horticulture.
The increase in temperature and carbon dioxide concentration and changes in rainfall patterns and their interactions are expected to make the soils susceptible to salinisation; reduced water and nutrient availability; altered carbon and nitrogen dynamics that affect crop growth and microbial elements in the soil and a decrease in soil biodiversity, according to researchers DK Benbi and R Kaur, in their article Modelling Soil Processes in Relation to Climate Change.
Under drought conditions, root growth and function are impaired, which reduces their nutrient acquisition capacity, notes Horst Marschner, the author of Mineral Nutrition of Higher Plants.
A reduction in soil moisture reduces the soil’s functions and consequently affects a plant’s productivity, says academic Robert Mills.
Robusta coffee might be marginally more resistant to temperature increases than other varieties but it is more cold-sensitive. And some coffee-growing regions could benefit from increased carbon dioxide, which may increase the photosynthetic rate and heat tolerance of the plant, resulting in increased crop growth and yield, say some researchers.
But others argue that increasing drought stress and the potential effects of deforestation on the local climate could eventually outweigh this positive effect.
It is essential that coffee smallholders adopt strategies to adapt to the effects of climate change. To do this requires a combination of policy measures, technical solutions, research and best practices.
Also, increasing female farmers’ productivity and resilience to the effects of climate change could make a crucial contribution in meeting the future demand for coffee worldwide.
A coffee agroforestry system — the integration of shade trees in coffee — is gaining popularity. Agroforestry systems can contribute to both climate change mitigation and adaptation efforts by sequestering carbon and increasing landscape resiliency.
Shade-tree cover, which is known to ameliorate extremes of weather and provide natural enemies of pest species, might also increase understory pests and diseases.
Other adaptation measures include system diversification; use of drought tolerant and disease resistant varieties; integrated pest management; use of cover crops, mulch, and manuring; rain-water harvesting; conservation tillage; terracing; irrigation and crop rotation.
The National Agricultural Research Organisation’s National Coffee Research Institute develops training materials on climate change mitigation and adaptation strategies for farmers and provides coffee growers with shade tree seedlings.
The institute focuses on developing drought-tolerant coffee varieties, efficient water-use systems and alternative uses of coffee waste.
It has also developed 10 varieties that are more resistant to coffee wilt disease, which is caused by a fungus in the soil that appears to increase when temperatures rise.
Uganda’s coffee farmers are proving resilient and innovative. Many are adopting climate-smart agricultural practices to mitigate and adapt to the impacts of climate change.
This is essential because the reduction in coffee production and quality affects prices on the global market.
My climate action call goes to all environmentalists and agricultural actors, academia and media moguls to join synergies in ensuring that the coffee value-chain system thrives to cater for people’s livelihoods and brings the world that cherished cup of coffee every morning.
Robert Kigongo is a sustainable development analyst.
