Excessive rainfall threatens global cocoa yields

A study published in the journal PNAS by researchers from Harvard University and Ghana indicates that excessive rainfall, rather than just drought or heat, poses a major threat to global cocoa harvests. The research highlights that intense rainfall during sensitive stages, such as flowering and early pod development, can ruin crops and promote fungal diseases.

By analyzing twenty years of data from the Ghana Cocoa Board, researchers found that the combination of excessive rain during the April-June wet season followed by extreme drought explains approximately two-thirds of year-to-year yield fluctuations in Ghana. Similar trends were observed in major producing regions including Ecuador and Indonesia.

These climate-driven fluctuations have contributed to significant volatility in global cocoa prices, which tripled in 2024 due to weather extremes in Côte d’Ivoire and Ghana. Scientists are calling for more precise forecasting systems to help the nearly six million smallholder farmers worldwide prepare for large-scale climate events like El Niño.