Scientists are racing to protect the global supply of coffee and chocolate from the escalating threats of climate change. As volatile weather patterns disrupt harvests and drive prices to record highs, researchers are developing new, hardier varieties of coffee and cacao plants. These efforts are critical for the livelihoods of millions of small-scale farmers and for ensuring these beloved commodities remain available to consumers worldwide.
The core of the problem lies in the increasing frequency of droughts, the spread of fungal diseases like coffee leaf rust, and extreme temperatures that reduce crop yields and quality. In response, an international coalition of scientists, backed by EU funding, is focusing on innovative techniques such as grafting, which can rapidly introduce climate-resilient traits into established crops. This approach, combined with broader strategies like agroforestry, aims to create a more sustainable and resilient future for two of the world’s most popular agricultural products.
Mounting Pressures on Farmers
Producers of coffee and cacao are on the front lines, experiencing the direct consequences of a changing climate. In the coffee-growing regions of Nicaragua, for instance, farmers have been dealing with the effects of severe drought. One long-time farmer, Juan Pablo Castro, observed the appearance of “vain beans” in 2023, a condition where the coffee cherry is either empty or contains a single malformed bean instead of the usual two. These defective beans are lighter and get washed away during processing, representing a direct loss of product and income.
Another significant, climate-exacerbated issue is the proliferation of coffee leaf rust, a fungal disease scientifically known as Hemileia vastatrix. The disease manifests as yellow-orange spots on the plant’s leaves, weakening it and drastically reducing its ability to produce healthy coffee cherries. It stands as one of the most substantial threats to coffee production globally. These challenges are not isolated to Central America. In West Africa, which produces over half of the world’s cocoa, farmers in Ghana and Côte d’Ivoire are facing unprecedented changes in rainfall patterns, leading to significant shortfalls in global supply.
Grafting as a Fast-Track Solution
To combat these threats, researchers are turning to grafting, a horticultural technique that joins the top part of a known plant variety with the root system of a hardier one. This method offers a crucial advantage: speed. Traditional plant breeding, which involves cross-pollination and years of cultivation to create a new variety, can take between 20 and 30 years. This timeline is too slow to keep pace with the rapid shifts in climate. Grafting provides a much faster way to adapt.
The EU-funded BOLERO initiative, coordinated by French plant biologist Sophie Léran, is pioneering this approach. The project focuses on taking established, approved coffee and cacao varieties—known for their flavor and quality—and grafting them onto rootstocks that are adapted to specific environmental stressors, such as drought. By using the roots of wild or robusta coffee varieties, which are naturally more resilient, farmers can continue to cultivate their preferred beans on plants that are better equipped to survive longer and maintain production levels in challenging conditions.
The Untapped Potential of Agroforestry
Beyond genetic resilience, the way coffee and cacao are farmed is also undergoing a critical re-evaluation. Historically, both crops grew naturally in the shade of taller forest trees. However, modern agricultural practices have often favored monoculture farming in direct sunlight to maximize short-term yields. This has led to deforestation, degraded soil quality, and increased vulnerability to pests and heat.
Restoring Shade to Farms
New research highlights the significant, unrealized benefits of reintroducing trees to coffee and cocoa farms, a practice known as agroforestry. A study focusing on West Africa found that cocoa farms in Ghana and Côte d’Ivoire had an average tree shade cover of just 13%, far below the 30–50% level under which cocoa can be grown without significant yield losses. Planting more shade trees could dramatically increase carbon sequestration, creating a “win-win situation” that benefits the environment without harming crop production. These trees also help create cooler microclimates, improve soil health, and reduce water stress and pest outbreaks, which can lower costs for farmers.
Economic and Ecological Benefits
Agroforestry programs are being implemented to regenerate land and protect vital watersheds. Initiatives like the Solidaridad Climate Heroes Project are helping small-scale farmers in multiple countries plant trees alongside their crops. This not only improves the farm’s ecosystem but also allows farmers to generate and sell Carbon Removal Units, creating an additional income stream. Corporate programs, such as Nestlé’s Income Accelerator, are also supporting these efforts by working with organizations like the Rainforest Alliance to plant shade trees and promote sustainable practices.
A Converging Threat from Pollinator Loss
In addition to direct climate impacts on the plants themselves, researchers have identified a growing threat to the insects that pollinate them. Many tropical crops, including cacao and coffee, are at high risk of losing their pollinators due to habitat loss and rising temperatures. The cacao tree is particularly vulnerable, as it is almost exclusively pollinated by a specific type of midge that thrives in the damp, shaded environments that are disappearing.
A study published in Science Advances warns that the combination of specialized pollination, high dependence on animal pollinators, and cultivation in regions set to experience novel temperatures by 2050 creates a “perfect storm of threats.” While some technological solutions exist, such as hand-pollination, they are labor-intensive and would significantly increase production costs. Experts emphasize that the most effective solutions are to mitigate climate change by reducing greenhouse gas emissions and to preserve and restore natural habitats to support pollinator populations.