The climate crisis drove weeks of high temperatures in the west African region responsible for about 70% of global cacao production, hitting harvests and probably causing further record chocolate prices, researchers have said.
Farmers in the region have struggled with heat, disease and unusual rainfall in recent years, which have contributed to falling production.
The study, by the independent research group Climate Central, found the trend was particularly marked in Ivory Coast and Ghana, the two biggest cacao producers.
Using data from 44 cacao-producing areas in west Africa and computer models, the researchers compared today’s temperatures with a counterfactual of a world not affected by global heating.
The researchers looked at the likelihood of these regions facing temperatures in excess of 32˚C (89.6˚F) – above levels considered optimum for cacao trees.
The report calculated that over the last decade, global heating had added an extra three weeks of temperatures exceeding 32˚C in Ivory Coast and Ghana during the main growing season between October and March.
Last year, the hottest year globally on record, they found global heating drove temperatures above 32˚C on at least 42 days across two thirds of the areas analysed.
Many other factors were potentially harming cacao trees and boosting prices, they noted, including mealybug infestations, rainfall patterns, smuggling and illegal mining.
Narcisa Pricope, a professor at Mississippi State University, said the crop faced an “existential threat” largely because of increasingly dry conditions in cacao-producing regions.
Pricope was part of recent research from the United Nations Convention to Combat Desertification that found more than three-quarters of the Earth’s landmass had become drier over the past 30 years.
The emissions of greenhouse gases were the biggest cause of this aridity, she said, but practices that degraded soils and nature also played an important role.
“Collective action against aridity isn’t just about saving chocolate – it’s about preserving the planet’s capacity to sustain life,” she said.