Climate Change is Altering the Growth Cycle of Arabica Coffee

Typically, Arabica coffee thrives in tropical forests at altitudes of 1,500–2,800 meters above sea level, between latitudes 4°N and 9°N. In these regions, seasonal temperature fluctuations are minimal, with annual average temperatures between 18 and 22°C. Rainfall is evenly distributed, ranging from 1,600 to over 2,000 mm, with a dry season lasting 3 to 4 months coinciding with the cooler months. In such an environment, Arabica coffee grows well as an understory shrub and yields high-quality beans.

However, Arabica coffee is highly sensitive to environmental conditions, particularly photoperiod changes and meteorological factors like rainfall distribution and air temperature, which impact plant phenology, yield, and bean quality.

Research by scientist Camargo shows that when environmental temperatures exceed 23°C, the development and ripening of Arabica cherries accelerate, often resulting in reduced quality. Studies by Damatta & Ramalho indicate that prolonged exposure to daily temperatures of 30°C can disrupt growth and lead to abnormalities, such as yellowing leaves. High temperatures also disrupt the plant’s metabolic processes, with leaves absorbing more energy from radiation than can be utilized in photosynthesis, causing overheating and leaf drop.

In addition, relatively high air temperatures during the flowering period, especially when combined with extended dry seasons, can result in flower drop and a lower fruit set. Rapid plant growth may also lead to lower coffee bean quality. High maximum temperatures during summer can cause over-ripening of cherries, reducing fruit quality.

Moreover, climate change has led to an increase in extreme conditions, such as frost, which can cause physiological stress, lower photosynthesis efficiency, increase disease susceptibility, and heighten irrigation needs. Key stages like flowering and seed development are linked to the dormancy phase of buds, with high temperatures and dry conditions during the reproductive phase critically affecting yield and coffee quality. Establishing proper air temperature limits for coffee is crucial for determining the crop’s economic distribution and viability.

A report from Infobibos also highlights that climate change is a major factor in coffee yield variability and decline worldwide. The relationship between climate variables and agricultural production is complex, as environmental factors impact crop growth and development at various stages in the coffee plant’s lifecycle. Photosynthesis becomes restricted under water stress, with stomata closing and other physiological activities decreasing. Other climatic factors can also reduce yield, such as adverse air temperatures during different growth stages.

The report notes that coffee yields in tropical Asia are sensitive not only to rising temperatures but also to changes in monsoon characteristics. In semi-arid tropical Africa, climate change has increased drought frequency, posing the greatest risk to agriculture. In Latin America, air temperatures are projected to rise by 1°C to 5.8°C, with rainfall increasing by 15% in tropical regions of Brazil. Agriculture and water resources face significant impacts due to extreme temperatures and rainfall variability. Although these projections are concerning, it’s important to note that the reports carry a degree of uncertainty regarding long-term forecast outcomes.