Coffee and climate change
Here’s why trees could save coffee production from climate change
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Once the Covid-19 pandemic will be swept away by mass vaccination programs, we will most likely feel that we have finally gotten our world back. No more virus, no more problems which are threating our daily lives (at least in the Western World). It will be then, when we will be enjoying a cup of hot coffee in front of the TV that we will hear back on the news a problem that the virus outbreak put in the background: climate change. Yes, because although it seems that the pandemic has somewhat contributed to lower the CO2 emissions, at the expenses of airlines and factories, climate change is far from being a “long-gone” issue.
Why did I mention early on a “cup of coffee”? Simple, if you type on google “climate change” you get around 769.000.000 results. If you type “climate change coffee”, you get 102.000.000 results. To my despair as well, coffee production is being and will keep being heavily affected by climate change, with the concrete risk of impacting the production and supply chain of one of the major commodities worldwide. But how and why climate change can threaten our morning cup of coffee?
How coffee production areas will be impacted by climate change?
As you probably know, coffee production extends throughout the equator from Central/South America to Indonesia, but the two major coffee species, Coffea arabica and robusta, have very different environmental requirements (Teketay, 1999):
- Coffea arabica, which accounts for 70% of the global coffee production, originates from the Ethiopian highlands, but it is nowadays grown not only in East Africa but also in Central America and in the Andean regions of South America. It grows best above 600 m a.s.l., in a cool environment.
- Coffea robusta, which accounts for 30% of the global coffee production, originates from West and Central Africa. Differently from Coffea arabica, it grows best at lower altitudes, in a warm and humid environment. Nowadays important production centers can be found in South-East Asia (Indonesia) and in the lowlands of West Africa.
Under climate change, the temperature increase and the modified precipitation patterns will severely impact the coffee production areas. By the year 2050 Central America and East Africa are expected to experience a temperature rise by 2–2.5 and 1–2°C respectively, in combination with an increased incidence of drought events. In Uganda and Indonesia, the rainy season will become more unpredictable and exteme precipitation events are expected to increase in frequency. The delayed onset of the rainy season, along with heavy rainfall events, are expected to cause a fall in production by 50–70% in Uganda and by 80% in Indonesia. In Colombia, which has the third highest average annual global coffe production (11,5 million bags), temperature is expected to rise by 1.5–2.5 °C by 2050 and extreme rainfall events will become more frequent. As a consequence, coffe production will most likely experience a shift to higher altitudes, in order to cope with the increased temperature.
According to a report by the PUR project on sustainable sourcing coffee, 50% of the suitable areas for coffe production will be lost by the year 2050 due to climate change.
Effects of climate change on coffee production
After the apocalyptic description of what will happen to the coffee sourcing areas, you will be curious (and worried) to know what on Earth will happen in practice to coffee, to provoke such a disaster. Here you go:
- Increasing temperatures. The increasingly higher temperatures and heat waves under climate change scenarios will hamper the growth and development of the coffee plant: Coffea arabica has a growth temperature range between 15 and 25°C while robusta between 20 and 30°C. Beyond these tresholds, flowering is put at risk due to an increased abortion rate and the cherries will develop much faster which a consequent detrimental effect on the coffee quality.
- Water stress. Along with increased temperature, erratic rainfalls will become one of the major abiotic constraints for coffee production. Plants which are usually grown between 2000 and 3000 mm/year will experience prolonged periods of drought or excessive precipitation. This will impact the physiology of the plant, especially photosynthesis, which is the driver for growth and development. Heavy rains are also expected to damage the cherries, directly impacting the quality and quantity of the harvests.
- Pest and diseases. In combination with a hotter environment, coffee pests like leaf miners or coffee rust are likely to spread more easily and aggressively (de Sousa et al., 2019). At this stage the use of chemicals for pest control will become the sole option to save the harvest.
In addition, the modified climate on Earth will likely lead to a redistribution of the areas suitable for coffee production: under a hotter climate, coffee plantations will probably move away from the equator and more and more towards cooler mountain areas and subtropical regions. As a consequence the rural communities which are now growing the coffee beans for our morning delight will be left behind.
Coffee agroforestry systems can support production under climate change
Agroforestry, a type of cropping system which consists in having on the same field annual or perennial (usually cash) crops with perennial plants (usually trees devoted to a whole different type of market e.g. timber production), might be pivotal in building resilient and high yielding coffee cropping systems.
Having a tree cover above the coffee plants has two major effects (Paulo, 2013):
- Creation of favourable environmental conditions for coffee plants growth.
- improved soil quality
- higher water availability for the coffee plants
- improved biodiversity by offering shelter and protection to insects for the pollination of the coffe plants.
2. Protection of the coffee plants.
- cooler microclimate which mitigates the effects of increased temperature expected under climate change.
- higher protection from heavy precipitation events by reducing the amount of rainfall reaching the ground and the energy with which the droplets impact the surface.
- better drainage of the water which percolates into the soil
- reduction in the risk of erosion
In addition to support a sustainable production under climate change, an agroforestry system provides the farmer with multiple sources of income: by setting up a cropping system which includes trees for the timber market, he can increase its revenue and have an alternative source of income, in case the coffee production would not go as planned.
P.S.
If you are interested in coffee, you might want to read more about sustainability issues linked to its production, and what you can do about it…click here!
References
de Sousa, K., van Zonneveld, M., Holmgren, M., Kindt, R., & Ordoñez, J. C. (2019). The future of coffee and cocoa agroforestry in a warmer Mesoamerica. Scientific Reports, 9(1). https://doi.org/10.1038/s41598-019-45491-7
Paulo, S. (n.d.). Impacts of Coffee Production in Agroforestry System for Sustainable Development. 11.
Teketay, D. (n.d.). History, botany and ecological requirements of coffee. 28.
