Resilience potential of the Ethiopian coffee sector under climate change Justin Moat 1,2 * , Jenny Williams 1 , Susana Baena 1,2 , Timothy Wilkinson 1 , Tadesse W. Gole 3 , Zeleke K. Challa 3 , Sebsebe Demissew 1,4 and Aaron P. Davis 1 * Coffee farming provides livelihoods for around 15 million farmers in Ethiopia and generates a quarter of the country’s export earnings. Against a backdrop of rapidly increasing temperatures and decreasing rainfall, there is an urgent need to understand the influence of climate change on coffee production. Using a modelling approach in combination with remote sensing, supported by rigorous ground-truthing, we project changes in suitability for coffee farming under various climate change scenarios, specifically by assessing the exposure of coffee farming to future climatic shifts. We show that 39–59% of the current growing area could experience climatic changes that are large enough to render them unsuitable for coffee farming, in the absence of significant interventions or major influencing factors. Conversely, relocation of coffee areas, in combination with forest conservation or re-establishment, could see at least a fourfold (>400%) increase in suitable coffee farming area. We identify key coffee-growing areas that are susceptible to climate change, as well as those that are climatically resilient. A rabica coffee (Coffea arabica) provides Ethiopia with its most important agricultural commodity, contributing around one quarter of its total export earnings 1 . In 2015/16, Ethiopia exported around 180,000 metric tonnes of coffee 2 at a value in excess of 800 million USD, making it Africa’s largest coffee producer and the world’s fifth largest coffee exporter 2 , despite the fact that around half of the coffee produced each year is consumed in- country 3 . Coffee farming provides a livelihood income for around 15 million Ethiopians (16% of the population), based on four million small-holder farms 2,4 . In Ethiopia, coffee is produced within specific agro-ecological zones, over numerous geographical and political boundaries. At least 80% of Ethiopia’s coffee comes from forests, forest-like habi- tats, or farms with shade (canopy) cover, representing land coverage of around 19,000 km 2 (Fig. 1) with around another 4,000 km 2 (c. 20%) grown in small plots in partial shade or full sun. Most of the coffee is grown in areas that are covered, or were previously covered 5 , with humid evergreen forest: Moist Afromontane Forest (MAF) and Transitional Rain Forest (TRF) 6 . MAF and TRF are found at 650–2,600 m (450–3,000 m including extremes), although coffee is mostly confined to 1,200–2,200 m. Coffee farming is also undertaken in association with a drier type of vegetation, classified as Dry Afromontane Forest 6 , such as that found in the Harar Zone (Fig. 1). The main coffee-growing areas of Ethiopia are found within the south-west and south-east (Oromia Region and Southern Nations, Nationalities and Peoples’ Region), with modest and minor production in the north (Amhara Region and Benishangul–Gumuz Region, respectively) (Fig. 1). Coffee farmers and other coffee sector stakeholders in Ethiopia and East Africa report that coffee production has been negatively influenced by changes in climate. These changes include: an increase in the uncertainty of yearly weather patterns, particularly in precipitation variability and timing of the wet season; an exten- sion of the dry season (shortening of the wet season); a more extreme (drier and hotter) end to the main dry season; more intense (extreme) weather (heavier rain, hotter days); and warmer nights 7,8 . Historical climate data shows that the mean annual temperature of Ethiopia has increased by 1.3 °C between 1960 and 2006, at an average rate of 0.28 °C per decade 9 and by 0.3 °C per decade in the south-west 10 and Amhara in the north 11 . These temperature increases have been most rapid in the main wet season (July to September) at a rate of 0.32 °C per decade 9 . Analyses of extreme temperature changes in various coffee-growing areas indicate posi- tive trends for maximum temperature, warm days, warm nights and warm spell duration; and negative trends for cool days, cool nights, and cold spell duration across different eco/agricultural environ- ments (pastoral, agro-pastoral and highland), although some of the trends are not statistically significant 12 . The strong variability within Ethiopia’s annual and decadal rainfall makes it difficult to detect long-term, country-wide trends 13 . Despite these limitations, studies show: that February to May 14 and June to September rains have declined 13,15,16 ; a 15–20% reduction in rainfall since the mid- 1970s 17 and late 2000s in southern, south-western and south- eastern Ethiopia, particularly in the period of the initial early (February to March) rains in the south-east and east 18,19 , with an increase in drought frequency in all parts of Ethiopia during the last 10–15 years 16 ; a decrease in June to September precipitation in the Greater Horn of Africa by approximately 1 s.d. during the period 1950–1989, corresponding to decreases of over 30 mm per decade throughout much of the Ethiopian Highlands 20 ; and a down- ward trend in rainfall of 0.4 mm per month per year over the south- western region in the period 1948–2006 10 . The mean annual temperature of Ethiopia is projected to increase by 1.1–3.1 °C by the 2060s, and 1.5–5.1 °C by the 2090s, depending on the emission scenario 9 . Climate model projections under the emission scenarios A2 and B1 show Ethiopia warming in all four seasons across the country 21 . Projections from different General Circulation Models (GCMs) are broadly consistent in 1 Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, UK. 2 School of Geography, University of Nottingham, Nottingham NG7 2RD, UK. 3 Environment and Coffee Forest Forum (ECFF), PO Box 28513, Addis Ababa, Ethiopia. 4 The National Herbarium, Department of Plant Biology and Biodiversity Management, College of Natural Sciences, Addis Ababa University, PO Box 3434, Addis Ababa, Ethiopia. *e-mail: j.moat@kew.org; a.davis@kew.org ARTICLES PUBLISHED: 19 JUNE 2017 | VOLUME: 3 | ARTICLE NUMBER: 17081 NATURE PLANTS 3, 17081 (2017) | DOI: 10.1038/nplants.2017.81 | www.nature.com/natureplants 1 © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.