Heavy Rainfall Threatens Global Cocoa Supply and Drives Price Risks
Accra, Tuesday, 15 September 2026.
A Harvard study reveals extreme rainfall, rather than drought, is the main climate threat to global cocoa yields, accounting for two-thirds of Ghana’s annual harvest volatility.
Harvard Study Identifies Rainfall as Primary Cocoa Risk
New academic research from Harvard University highlights that extreme rainfall in West Africa poses a major, under-appreciated threat to cocoa yields by damaging flowering trees and young pods [1]. Published in the Proceedings of the National Academy of Sciences, the study identifies extreme rainfall, rather than heat or drought, as the primary climate-driven risk to global cocoa yields, specifically causing damage to sensitive flowers and young pods and increasing fungal infections like black pod disease [2]. The research analyzed district-level production data against climate variables in Ghana, the world’s second-largest producer, with findings of yield loss due to extreme rain also replicated in Ecuador and Indonesia [1]. Anna Lea Albright, an environmental fellow at Harvard University, noted that while heat and drought matter, the strongest weather risk to cocoa is actually heavy rainfall, particularly during the flowering season [2]. This pattern was observed in all three countries studied, which are major cocoa producers, emphasizing that rainfall harmful to cocoa is linked to larger-scale climate patterns such as El Niño [3]. The study indicates that excessive rain during the April–June wet season damages flowering and young cocoa pods, interferes with pollination, and promotes fungal black pod disease via rain splash dissemination [4].
Market Volatility and Economic Implications
Coupled with existing challenges like prolonged drought, aging crop infrastructure, and shrinking farmland in primary producing nations like Ghana and Ivory Coast, these climate-driven disruptions threaten to further destabilize global cocoa commodity markets [1]. Cocoa prices have significantly increased, with current prices hovering around $6,000 USD per tonne as of 14 September 2026, compared to the $2,000–$3,000 USD range maintained from 2014 until 2024 [1]. In 2024, prices peaked above $12,000 USD due to heavy flooding in West Africa, representing a calculated increase of 300 percent from the upper bound of the historical average range [1]. Raw cocoa prices tripled in 2024, leading to consumer impacts such as higher prices, smaller product sizes, or reformulated chocolate goods [2]. Economic analysis suggests that even substantial price increases for chocolate products will not translate into improved future conditions for cocoa farmers and harvesters, as the bill has historically been footed by smallholder farmers in West Africa [1]. The study found that intense rainfall during the wet season is strongly linked to cocoa yield losses in major producing regions, explaining approximately 68% of year-to-year yield variability in Ghana [4].
Future Outlook and Adaptation Strategies
A strong El Niño is currently developing, a climate pattern typically associated with heavy rainfall in coastal Ecuador and drier conditions in West Africa and Indonesia as of 13 September 2026 [2]. Research teams are currently developing predictive capabilities to forecast heavy rainfall months in advance to allow farmers to implement protective measures, such as enhancing canopy cover or retaining leaf litter to mitigate fungal infection spread from soil to cocoa pods [2]. In early 2026, Nestlé partnered with a German startup to produce ChoViva, a cocoa-free chocolate alternative made from sunflower seeds, aimed at creating a more resilient supply chain as climate volatility threatens traditional smallholder cocoa farming [1]. While climate change poses a long-term risk, current climate models lack the precision to accurately predict future rainfall climatology or patterns over West Africa [2]. The findings could help improve early warning systems for cocoa farmers, shifting attention away from average climate conditions and towards short, intense weather events [4]. However, limitations of the study include the use of district-level production data as a proxy for yield in Ghana and the influence of non-climatic pressures such as aging trees, mining, smuggling, and changing market prices [4].