Grown predominantly in tropical highlands, Arabica coffee (Coffea Arabica) dominates global production, making up about 70 per cent of supply. Low-lying areas supply Robusta (Coffea canephora ) destined mainly for the low-quality, instant coffee market. The yield and flavour of coffee, as well as pest and disease activity, are tightly linked to climate and weather, particularly temperature and moisture. Robusta is less heat-sensitive but Arabica performs best at 18–21°C.
Above 23°C, the plant grows too fast and fruits too early, damaging bean quality, with plant health declining with prolonged warmer conditions. Even half a degree at the wrong time can make a big difference in coffee yield, flavour, and aroma.
Around the Bean Belt, rising minimum growing temperatures, changes in rainfall patterns, and rising pest and disease incidence, are already making life harder for coffee farmers.
The coming decades are likely to see dramatic shifts in where and how much coffee is produced worldwide. Regional studies suggest rising temperatures could render much Mexican coffee unviable by the 2020s, and most of Nicaragua will lose majority of its coffee zone by 2050, and Tanzanian Arabica yields are projected to reach critically low levels by 2060.
According to a 2015 global study, hotter weather and changes in rainfall patterns are projected to cut the area suitable for coffee in half by 2050 across different emissions scenarios. The details differ markedly with locality, but the impacts are likely to be heaviest at low latitudes and low altitudes. Elsewhere, the predicted effects are still negative albeit less pronounced. Brazil and Vietnam—two of the biggest producers—appear set to experience substantial losses. Conversely, the climate of 2050 seems to favour some areas, particularly in the highlands of East Africa—as well as in Indonesia, Papua New Guinea, and the Andes. Before the century is out, however, conditions are set to become inhospitable for Arabica coffee in the wild in East Africa—its centre of origin.
This report discusses: how climate change is affecting the world’s coffee regions; the impacts on coffee pests and diseases; how climate change is likely to affect where coffee is grown; the risks to producers, workers, and their communities. It also looks at the capacity coffee farmers have to adapt. Crop adaptation strategies include developing more resilient production systems, diversifying crops, and shifting plantations upslope. While farmers are generally resourceful and creative, their flexibility and resilience is not unlimited. Their capacity to grapple with change is tied to education, access to information, health, equity, food security, and other factors, some of which are beyond their control, such as global markets.
While some regions may see new opportunities, many producers will not be in a position to realise them. Migrating coffee plantations to new areas is not straightforward, not least because it takes several years for new plants to become productive. With some exceptions, smallholder farmers, particularly in Africa, are not well organised. Few are members of cooperatives and those that do exist are weak. Moreover, investment in research, development, and extension is meagre, with little knowledge sharing. Most coffee farms show low productivity, relatively poor management, and are slow to adopt best practices.