The demand for coffee and cocoa all over the world is on the rise. However, across the equatorial belt where these two crops are produced, the future is not looking bright. Climate change in the tropics is pushing coffee and cocoa to the limits of physiological tolerance and constraining the places where they grow in the future.
How coffee and cocoa could affect the distribution of these crops from Panama to Central Mexico is what a new study examined. Coffee production, particularly Arabica coffee, will possibly decrease as global warming and extreme weather events reduce the geographical areas where it grows best, and increase susceptibility to pest and disease outbreaks - in 2017, coffee leaf rust affected 70 percent of the coffee farms in Central America.
The study concluded that half of the current coffee plantations that are vulnerable to global warming in the future could be replaced by cocoa. The leading author of the study and a Research Fellow, Kaue de Sousa, highlighted that this situation opens a window of opportunity for climate change adaptation. The interest of smallholder farmers in cocoa is growing, driven by the vulnerability of coffee in the changing climate. Now, there is a need to build capacity among smallholders to adapt their crop systems successfully.
Both coffee and cocoa are mostly grown under agroforestry management, where trees are incorporated into farming systems. The Senior Ecologist at World Agroforestry, Roeland Kindt, said that coffee and cocoa are both traditionally grown under tree shade to reduce heat stress and conserve soil, but the shade trees are typically ignored in most future climate change studies. Also, the agroforestry approach brings additional ecosystem services, which make the production system more resilient, for instance, by conserving water and providing habitats for birds and insects, which can act as natural pest predators.
Milena Holmgren, Expert on Ecosystem Resilience to Climate Variability at Wageningen University, said that agroforestry systems are clear examples of how positive interactions between plants can ameliorate harsh growing conditions and facilitate agricultural productivity. The new study explored which tree species may be more successful in future coffee and cocoa plantations to create more benign microclimates.
The team examined the top ten trees currently present in coffee and cocoa agroforestry systems, and they identified that they are the ones most vulnerable to climate change. The researchers discovered that the distribution range of almost 80 percent of tree species in coffee areas and 62 percent on cocoa areas would drastically shrink.
These include tree species that are essential for fruit (mango, guava, and avocado) and timber (cedar), as well as an estimated 56 percent loss of nitrogen-fixing trees (poro and guama), which can enhance soil productivity and conservation. De Sousa added that despite the concerning decreases in tree suitability; the new study provides alternatives for coffee and cocoa agroforestry under the climate emergency faced by farmers today.
