Kew scientists reveal that 60% of wild coffee species are threatened with extinction, causing concern for the future of coffee production

Work by scientists at the Royal Botanic Gardens, Kew highlights that over half of wild coffee species are at risk of extinction.

Release date: 16 January 2019

  • Work by scientists at the Royal Botanic Gardens, Kew highlights that over half of wild coffee species are at risk of extinction 
  • This includes Arabica (Coffea arabica), the origin of the world’s most popular coffee, which is now categorised as an endangered species
  • Scientists at Kew say current conservation measures for wild coffee species are inadequate to ensure the long-term future of the world’s favourite beverage

For the first time ever, scientists at Royal Botanic Gardens, Kew, have carried out an International Union for Conservation of Nature (IUCN) Red List of Threatened Species™ assessment for all 124 coffee species. The implications of these findings, published today in leading research journals Science Advances and Global Change Biology, paint a picture of concern for the long-term future of global coffee production.

The newly published research reveals that 60% of all wild coffee species are under threat of extinction due to deforestation, climate change, and the spread and increasing severity of fungal pathogens and pests. This includes the wild relative of Coffea arabica, the world’s favourite and most widely traded coffee, which has entered The IUCN Red List as an Endangered species, largely due to climate change projections.

Outcomes based on more than two decades of research

These new figures come after two decades of dedicated research undertaken by Kew to discover, analyse and document the world’s coffee species, and assess their extinction risk. Much of this work was undertaken first-hand in the wild locations where coffee grows, mainly in the remote forests of Africa and on the island of Madagascar. In 2012, Kew researchers and in-country collaborators revealed a bleak picture for wild Arabica. Using computer modelling they were able to project how a changing climate would affect the species in Ethiopia, showing that the number of locations where Arabica grows could decrease by as much as 85% by 2080. In 2017, the Kew-Ethiopia team turned its attention to the influence of climate change on coffee farming, showing that up to 60% of the land used for Ethiopia’s coffee production could become unsuitable for use by the end of the century. This recent work continues Kew’s long-standing research on wild coffee species, which dates back to the mid-1800s.

The results of the research published today, showing that 60% of all coffee species are threatened with extinction, is an extremely concerning outcome. The multi-billion-dollar coffee sector is founded on, and has been sustained through, the use of wild coffee species. Included among the 60% under threat of extinction are those that could be key to the future of coffee production. The global coffee trade currently relies on only two species – Arabica (c. 60%) and Robusta (c. 40%) – but given the myriad of emerging and worsening threats to coffee farming globally, other coffee species are likely to be required for coffee crop plant development.

Dr Aaron Davis, Head of Coffee Research at Kew and lead author of the Science Advances paper, says“Among the coffee species threatened with extinction are those that have potential to be used to breed and develop the coffees of the future, including those resistant to disease and capable of withstanding worsening climatic conditions. The use and development of wild coffee resources could be key to the long-term sustainability of the coffee sector. Targeted action is urgently required in specific tropical countries, particularly in Africa, to protect the future of coffee.”

“We hope our findings will be used to influence the work of scientists, policy makers and coffee sector stakeholders to secure the future of coffee production — not only for coffee lovers around the world, but also as a source of income for farming communities in some of the most impoverished places in the world.”

Dr Eimear Nic Lughadha, Senior Research Leader in Kew’s Conservation Department and lead scientist for Kew’s Plant Assessment Unit which co-ordinates extinction risk assessments for > 1,000 species a year, says: “This is the first time an IUCN Red List assessment has been carried out to find the extinction risk of the world’s coffee, and the results are worrying. A figure of 60% of all coffee species threatened with extinction is extremely high, especially when you compare this to a global estimate of 22% for plants. Some of the coffee species assessed have not been seen in the wild for more than 100 years, and it is possible that some may already be extinct. We hope this new data will highlight species to be prioritised for the sustainability of the coffee production sector so that appropriate action can be taken to safeguard their future.”

The future of wild Arabica coffee (Coffea arabica)

The importance of Arabica to Ethiopia is paramount. Ethiopia is the natural birthplace of wild Arabica coffee and Africa’s largest coffee exporter, with an annual export value of c. US$ 1 bn, and c. 15 million of its population engaged in coffee production. Wild Arabica coffee is an important source of seed stock for coffee farming, a source of disease resistance, and also a harvested crop in its own right, but could be in serious jeopardy if conservation action is not taken to protect the plant from a changing climate and deforestation. The second paper, authored by Kew and Ethiopian researchers and published in Global Change Biology this week, reports the status of Arabica coffee, never-before formally assessed for its extinction risk. Their detailed assessment includes climate change projections, which show the species to be endangered, with its natural population estimated to reduce by up to 50% or more by 2088 due to climate change alone.

Kew’s work is not undertaken with the aim of presenting bleak prospects for crop species like Arabica coffee, but is instead about understanding risk so that appropriate intervention and planning measures can be put in place. Kew’s research shows that appropriate interventions – for example, assisted migration, forest preservation and regeneration - could make a substantial difference to the future of wild Arabica coffee in Ethiopia, reducing the risk of extinction with long-term benefits for Ethiopian coffee farming, which is a critical component of Ethiopia’s economy.

Dr Justin Moat, Head of Spatial Analysis at Kew and one of the authors of the paper, says: Our initial evaluation of Arabica coffee suggested that it was not threatened with extinction in the wild. However, after factoring in climate change, it moved upwards by two categories to become an endangered species. These findings are so important as they indicate that the extinction risk to many other coffee species could be much worse if we consider climate change.

Dr Tadesse Woldermariam Gole, Senior Researcher for Environment, Climate Change and Coffee Forest Forum and Arabica coffee expert, says: “Ethiopia is the home of Arabica coffee, where it grows naturally in our upland rainforests. Given the importance of Arabica coffee to Ethiopia, and the world, we need to do our utmost to understand the risks facing its survival in the wild.”

Lost and found: case study of a threatened and ‘lost’ coffee species

Coffea stenophylla, otherwise known as the ‘Highland Coffee of Sierra Leone’, represents something of an enigma among coffee species. Growing in isolated forest patches in a few countries in West Africa, it is fabled as having an exquisite flavour that is said to surpass Arabica coffee. However, despite its potential and notoriety, no one had seen this species in the wild since 1954, and it has all but disappeared from coffee plantations and botanic gardens.

In December 2018, Dr Aaron Davis and Prof Jeremy Haggar (University of Greenwich) undertook a dedicated mission to Sierra Leone to find this species, after other stakeholders had failed to locate it in that country. Many of the original forest sites for C. stenophylla have long been lost, but on visiting the last known locality, a single plant was found. Further plants were then located in a separate, new location, but only after several hours walking through dense forest to an isolated hilltop area. Unfortunately, both sites are severely threatened by deforestation and human encroachment.

It is not yet known the influence species like C. stenophylla will hold for the future of global coffee production. However, one thing is for certain: if wild coffee species become even more threatened, and even go extinct, our options for developing a resilient and sustainable coffee production sector rapidly diminish.


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Additional quote:

Craig Hilton-Taylor, Head of IUCN Red List Unit, says, “The climate change impacts on Arabica coffee (Coffea arabica) revealed by Kew’s research findings and IUCN Red List assessment raise serious environmental, economic and social concerns, particularly for the millions of smallholder farmers that rely on this crop for their livelihood. As reported in the paper published in Science Advances, the numerous wild relatives of the commercially grown crops, such as Arabica coffee, are essential to ensure the resilience of cultivated coffee in the face of climate change and other threats. The IUCN Red List aims to assess 160,000 species by 2020, including many wild relatives of commodity crops. There is mounting evidence that climate change is affecting many crops, not just coffee. The situation is alarming and is an important reminder of the need for effective species conservation.”

Research papers details: Under embargo until 2:00 pm U.S. Eastern Time (7:00 pm BST) Wednesday, 16 January

  • Publication: Science Advances

Article title: ‘High extinction risk for wild coffee species and implications for coffee sector sustainability’


  • Publication: Global Change Biology

Article title: ‘Least concern to endangered: Applying climate change projections profoundly influences the extinction risk assessment for wild Arabica coffee’


Notes to Editors

The Royal Botanic Gardens, Kew is a world famous scientific organisation, internationally respected for its outstanding collections as well as its scientific expertise in plant diversity, conservation and sustainable development in the UK and around the world. Kew Gardens is a major international and a top London visitor attraction. Kew’s 132 hectares of landscaped gardens, and Wakehurst, Kew’s Wild Botanic Garden, attract over 2.1 million visits every year. Kew was made a UNESCO World Heritage Site in July 2003 and celebrated its 250th anniversary in 2009. Wakehurst is home to Kew's Millennium Seed Bank, the largest wild plant seed bank in the world. Kew receives approximately one third of its funding from Government through the Department for the Environment, Food and Rural Affairs (Defra) and research councils. Further funding needed to support Kew’s vital work comes from donors, membership and commercial activity including ticket sales.

The IUCN Red List of Threatened Species and Toyota Motor Corporation

RBG Kew is increasing its efforts to identify plants threatened with extinction and produce thousands more extinction risk assessments, co-ordinated through Kew’s Plant Assessment Unit. This work benefits from Toyota funding, which is being channelled to Kew through Toyota Motor Corporation's five year partnership with the International Union for the Conservation of Nature to develop the Red List of Threatened Species (TM).  The partnership is a key project in the first phase of the Toyota Environmental Challenge 2050, a far-reaching global commitment to significantly reduce Toyota’s environmental impact and deliver positive benefits to the natural world.

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