A study conducted by scientists at the Royal Botanic Gardens, Kew (United Kingdom), in collaboration with scientists in Ethiopia, reports that climate change alone could lead to the extinction of wild Arabica coffee (Coffea arabica) well before the end of this century. The study, published in PLOS ONE on 7 November, uses computer modelling to predict the influence of climate change on naturally occuring populations. This is the first time such modelling has been conducted on any coffee species. To date, climate change studies on plantation coffee have been limited, despite the concerns of farmers and other industry stakeholders, the Royal Botanic Gardens said in a statement. The researchers used field study and ‘museum’ data (including herbarium specimens) to run bioclimatic models for wild Arabica coffee, in order to deduce the actual (recorded) and predicted geographical distribution for the species. The distribution was then modelled through time until 2080, based on the Hadley Centre Coupled Model, version 3 (HadCM3), a leading model used in climate change research, and the only one available that covered the desired time intervals, for several emission scenarios, at the resolution required (1 kilometre). Three different emission scenarios over three time intervals (2020, 2050, 2080) were used. The models showed a profoundly negative influence on the number and extent of wild Arabica populations. “Wild Arabica is considered important for the sustainability of the coffee industry due to its considerable genetic diversity,” the Royal Botanic Gardens reported. “The Arabicas grown in the world’s coffee plantations are from very limited genetic stock and are unlikely to have the flexibility required to cope with climate change and other threats, such as pests and diseases.” In Ethiopia, the largest producer of coffee in Africa, the report stated that climate change will also have a negative influence on coffee production. With the climate sensitivity of Arabica confirmed, this study supports the widely reported assumption that climate change will have a damaging impact on commercial coffee production worldwide. A visit to South Sudan (Boma Plateau) in April 2012, headed by World Coffee Research Executive Director Timothy Schilling (see GCR Story July 2012) provided an opportunity to test the modelling predictions via on-the-ground observation. On comparing these observations with a study on Arabica made on the Boma Plateau in 1941, the group found that not all of the environmental stress evident could be attributed to deforestation or agriculture over the 70-year period. “Coffee plays an important role in supporting livelihoods and generating income, and has become part of our modern society and culture,” said Aaron Davis, Head of Coffee Research at the Royal Botanic Gardens, Kew, in a statement. “The extinction of Arabica coffee is a startling and worrying prospect. However, the objective of the study was not to provide scaremonger predictions for the demise of Arabica in the wild. The scale of the predictions is certainly cause for concern, but should be seen more as a baseline, from which we can more fully assess what actions are required.” The modelling predicted that Arabica could be extinct in the South Sudan forests by the year 2020, due to climate change. Dr. Davis, who joined Schilling on the expedition, reported that this appears to be realistic given the poor health (lack of seedlings, loss of mature Arabica specimens, low frequency of flowering and fruiting) of the remaining populations observed in 2012. “As part of a future-proofing exercise for the long-term sustainability of Arabica production it is essential that the reserves established in Ethiopia to conserve Arabica genetic resources are appropriately funded and carefully managed,” added Tadesse Woldemariam Gole, from the Environment and Coffee Forest Forum in Ethiopia.