Expected global suitability of coffee, cashew and avocado due to climate change

on suitability was based on three parameters. However, likely impacts on the length of the dry season, soil factors, pest and disease pressure or risks associated with extreme weather phe- nomena were not taken into account due to their high uncertainties. Additionally, using datasets with a coarse resolution of 30 arc seconds (ca. 1km2) may fail to capture the variability of local characteristics [12], particularly topography, soil factors and microclimatic conditions. For global assessments, however, 30 arc seconds can be considered a high resolution that fits the scope of this study. Conclusions This study presents the first global evaluation of coffee arabica, cashew and avocado suitability combining both climate and soil factors. It also represents the first global assessment of climate change impact on cashew and avocado suitability. For the potential global growing regions of all three crops, climate requirements were more important limiting factors than land and soil requirements. High annual temperatures, low minimum temperatures, long dry seasons and low or high precipitation were the most relevant climate criteria. However, apart from pro- tected and artificial areas that were rated as unsuitable, low soil pH, steep slopes or unfavour- able soil texture were also important limiting factors in some areas. We therefore suggest combining climate and soil parameters in future modelling attempts to increase their signifi- cance, especially on a regional or local scale. Shifts in suitable growing regions due to climate change with both expansions and contrac-

tions were found for all three crops. Coffee proved to be most vulnerable to climate change with negative impacts dominating in all growing regions, primarily due to increasing tempera- tures. Compared to coffee, cashew and avocado were found to be more resilient to climate change. For cashew, which showed the highest suitability range, both positive and negative effects of climate change were found. While globally, the suitable cashew growing areas are expected to increase, in some of the main producing countries (e.g. India, Coˆte d’Ivoire and Benin), areas of high suitability are expected to decrease. Similarly, for avocado, the suitable areas are expected to expand globally, while the most suitable areas in some of the major pro- ducing countries (e.g. the Dominican Republic, Peru, Indonesia) might decrease. All three crops however profit from increasing minimum temperatures at high latitudes and high altitudes. The study has shown that climate change adaptation will be necessary in most major pro- ducing regions of all three crops. Adaptation measures can include site-specific management options, plant breeding efforts for varieties that are better adapted to higher temperatures or drought and in the case of coffee, replacement of arabica with robusta coffee in certain regions [2]. New production locations at higher altitudes and latitudes might create new market opportunities. However, policies and strategies are required to ensure that shifts in production locations will not lead to negative environmental impacts such as deforestation, loss of biodi-

versity or ecosystem services. Additionally, landowners and farmers in current and future pro- duction locations must be willing to change their management or grow a new crop. Therefore, adaptation measures and shifts in production will each have to be addressed in participative approaches that allow the engagement of local stakeholders. Acknowledgments We extend our thanks to Hanno Rahn for his support in geodatabase management, to Pascal Ochsner and Nikolaos Bakogiannis for their advice in spatial data analysis, to Dominik Klauser for his expert advice on the selection of crops, and to Caroline Hyde-Simon for proofreading. PLOS ONE Global suitability of coffee, cashew and avocado PLOS ONE | https://doi.org/10.1371/journal.pone.0261976 January 26, 2022 21 / 24