Does climate change put our morning cup of coffee at risk?

The second prize in the DDRN Essay Competition for University Students 2019 was awarded to Athina Koutouleas, Geosciences and Natural Resource Management, University of Copenhagen. The Assessment Committee wrote: “A very well written essay focusing on the reader throughout the story…Relating to an everyday situation really works well…The relevance of the research project is presented without drowning the reader in facts and figures…The final sentence effectively encourages the reader to reflect.”

Turning coffee into science

It is 7:05am and I drag myself into the kitchen in a slumber-like state. The sound of the coffee grinder goes. The deep, chocolatey aromas of the freshly ground Arabica beans hit my nose like a heavenly bouquet awaking my senses. Before I have even placed my lips on the edge of my cup, a feeling of calm washes over me. I am a coffee addict. I am addicted to the smell and taste of coffee, as well as those few minutes of calm that I get when sitting down for a cup of it.

Legend has it that coffee was first discovered in 850 by a goat herder from the Kaffa region in the Ethiopian highlands. He noticed strange behaviour of his herd, detected a small shrub with bright red berries, and decided that that must have been the source of their loud bleats, jumping and dancing. When I saw a Ph.D. position open for coffee ecophysiology, I almost began to bleat loudly and once accepted for the position, jumped and danced like those legendary goats.

Athina Koutouleas

A coffee-less world due to climate change?

The basis of my Ph.D. project is that many tropical crops are threatened by climate change, including Arabica coffee (Coffea arabica). This is not good news for us addicts. Changes in rainfall patterns, elevated temperatures and frequent drought episodes will lead to a 50% reduction in coffee production by 2050. Future generations will experience less flavour, less aroma and higher prices of the Arabica coffee that we all know, love and (over) consume. Furthermore, diminishing ecosystems suitable for production may eventually lead to the extinction of Arabica coffee altogether!

This is why 20 institutions and more than 100 researchers across Europe have partnered up to protect our favourite coffee bean from extinction as a part of the BREEDCAFS project (BREEDing Coffee for AgroForestry Systems). BREEDCAFS is devoted to developing a powerful selection tool for future breeding with and for farmers, researchers, roasters and industry alike to secure coffee production in the face of climate change.

Quick facts and figures: what do you know about your morning brew…?

There are more than 120 different coffee species (Source: Davis, 2011), yet only two species dominate mass production and export: Arabica and Robusta. Global coffee consumers demand the delicate acidic notes and flavours of Arabica compared to the higher yielding and more heat tolerant, Robusta. Consumer preference is reflected by the total export of approximately 80% Arabica compared to only 20% of Robusta coffee (Source: Coffee evolution). Coffee is grown across more than 50 countries in the tropics and subtropical regions of the globe. Small-hold farmers grow 80% of all coffee that we drink today and boy, do we drink a lot, with coffee being ranked as the 3rd highest consumed beverage worldwide, after tea and water. Each Arabica coffee tree produces between 300grams to 1kg of beans per season. It takes 100 coffee beans to make one cup of coffee on average. So if you drink 2 cups a day, coffee farmers are growing 18 coffee trees devoted just to you (Source: Tree Hugger). If you are like me and can easily get through 2 cups of coffee a day, it is no surprise that we need such a phenomenal number of coffee trees to sustain our current global demand. Globally, coffee is big business and has been estimated to generate over US$ 200 billion as a source of global income.

Can the forests save coffee?

Arabica coffee grows wild in the forest undergrowth and is sensitive to temperature fluctuations outside of its optimal 18 – 22 °C range. Because of this, early commercial production of coffee involved other trees that provided shade to the plantation and a subsequent cooling effect for the coffee trees. Today, plant breeding selection practices have led to the widespread use of new temperature-tolerant coffee trees, which are suitable for open-field, full-sun conditions. These varieties produce higher yields due to their genetics and the agronomic practice of planting more trees on the same plot. This shift in practice has resulted in a form of monoculture farming of coffee and has had consequential knock-on effects within the surrounding ecosystems (the birds’ and the bees’ habitats are dwindling). As we have been breeding coffee for temperature-tolerant coffee trees, the globe has been warming too. So much so that even the temperature-tolerant Arabica coffee varieties are beginning to suffer yield and quality losses under current climate conditions.

A low-tech solution to this issue adopted by many farmers growing coffee is agroforestry, which is simply defined as “agriculture with trees”. This means different trees and shrubs are grown along with crops and livestock in agricultural systems. Thanks to its multifunctional properties, agroforestry addresses the issues surrounding coffee and climate change, on an environmental, economic or socio-economic perspective as follows:

Environmental: Coffee bean production largely contributes to deforestation. The ecosystem within an agroforestry system is more diverse than open-field coffee farming and therefore provides habitats to a wider range of pollinators and plant species, promoting natural ecological relationships. Forest cover is a big contribution to carbon sequestration. Agroforestry systems will help increase the tropic and subtropical region’s contribution to tackling climate change.

Economic: Agroforestry systems provide the cooling effect that is needed to create a more favourable microclimate for Arabica coffee and thus yields and quality of the coffee can be sustained.

Socio-economic: The use of fast-growing, woody tree species in agroforestry systems also provides farmers with another revenue of income generated by the shade trees oils, fruits, seeds or wood. This means that small-hold farmers are less vulnerable to fluctuating coffee prices, as their income is not solely dependent on coffee.

Agroforestry is the cornerstone of the BREEDCAFS project. Today, we are looking to change the game by breeding coffee varieties for agroforestry systems instead of under open-field, full sun. BREEDCAFS aims to diversify the range of coffee varieties available to the small-hold farmers as a way to guarantee future production in a more sustainable and resilient way. In turn, this will guarantee your morning cup of liquid goodness.

Can we tailor-make coffee for future climates?

Arabica coffee lacks genetic diversity. In fact, all varieties of cultivated Arabica coffee are around 98.8% genetically similar. To offer a comparison, crops such as rice and soy are only 70 – 80% similar across cultivars. This makes Arabica much more vulnerable to extinction, as its adaptation potential to new climate conditions is limited by the gene shallow pool.

F1 hybrids (filial 1 hybrids) are a solution to this. These are the first generation of offspring distinctly different parental types. Unlike wild varieties, F1 hybrids are crossbred and selected for their performance and quality by plant breeders. F1 hybrids are often stronger and healthier than those produced naturally in the wild. Therefore, F1 hybrids have the ability to survive in adverse environmental conditions and can better ensure long-term coffee supply of diverse Arabica coffee for the future.

BREEDCAFS partners are putting new F1 hybrid varieties of Arabica coffee to the test in their ongoing breeding program for climate change resilience. The hybrid varieties are assessed under both controlled experimental conditions, which mimic Agroforestry systems and natural farming scenarios. The hybrids are examined for yield, quality and resilience to pests, disease and environmental stressors such as elevated CO2, high-light, heat and drought.

BREEDCAFS researchers are mitigating the extinction of Coffea arabica.

BREEDCAFS is well on its way to delivering resilient and market-integrated F1 Hybrids suitable for agroforestry systems under a changing future climate.

The F1 hybrids are currently being validated in experimental field studies and greenhouse trials in France, Portugal, Denmark, Nicaragua, Costa Rica, Cameroon, Vietnam and French Guiana. Data from these studies are feeding into a colossal cloud database, which BREEDCAFS have established by combining extensive phenotyping with transcriptomic analysis. This database is on a scale, which has never before been conducted on any other perennial tree crops and has the ambition to provide a molecular footprint for future coffee breeding.

The F1 hybrids are also being surveyed in ‘real life’ environments, cultivated by local farmers in five different study countries. In collaboration with these farmers, the agronomic, productive and economic performance of the hybrids are being determined. Roasters are simultaneously profiling the hybrids for their cup quality.

The unique combination of all this data means that the F1 hybrids are being scrutinised from the molecular leaf-level chemistry to the yield, cup quality and all the way back to the perception of the farmer. In order to promote the use of the new coffee hybrids adapted to agroforestry systems, superior hybrids will be propagated at a large scale and distributed to farmers free of charge. So, the next time you sit down for a cup of coffee, think about the hundreds of researchers and millions of farmers who are dedicating their time, intellect and resources to protect that warm beverage in your hand.

Read more about sustainability in future coffee production here: