Coffee is one of the most valuable traded commodities and comprises about 1% of the overall value of world trade. Coffee is today grown in more than 60 tropical countries of the world and accounts for a significant part of the foreign exchange earnings of many countries in Africa, Latin America, Asia and Central America. An estimated 25 million farmers depend on coffee for their livelihoods. Despite its importance for economy of many countries and for the livelihood of many small scale farmers world-wide, the coffee production and genetic resources are highly threatened by increasing temperature and precipitation that would occur as a result of climate change. Therefore, the objective of this paper is to review the impact of climate change on coffee production and genetic diversity and to suggest the possible mitigation and adaptation strategies to be followed. High temperature and erratic rainfall which is brought about by climate change reduces coffee yield and quality directly by affecting growth and development of the plant. It also encourages increased incidence of pests and diseases while stressing the growing conditions for coffee and affects coffee yield and quality indirectly. Moreover, predictions from global circulation models suggested that the change in temperature and precipitation could affect the spatial distribution of areas climatically suitable for Arabica coffee, and many regions could become unsuitable. Besides, wild coffee Arabica and coffee germplasm, which have conserved under ex-situ field gene-bank of Ethiopia and many other countries, are also under a high risk of extinction. Due to these reasons, most of the world leading coffee producers will be highly affected in the future. Therefore, coffee growing countries should be aware of the impact of climate change on coffee production and apply mitigation and adaptation strategies like using shade trees, high density planting, soil water conservation practices, use of pest, drought and heat tolerant varieties, irrigation, diversification and also changing the location of the coffee plantation in highland and cooler area. In addition, the wild coffee and coffee germplasm conserved under field condition must be conserved in different areas that are indentified to be relatively tolerant to climate change. In general, all studies predicted coffee suitability area using temperature and precipitation only and therefore, soil factors and other climatic variables which affect coffee suitability should be considered in their future studies.
Keywords: Coffee yield, Climate change, Germplsm, Mitigation and Shade trees