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 decline has resulted in an increase in the price of cocoa, which is produced from the beans of the cacao tree and is the main ingredient in chocolate.
A new report found that “climate change, due primarily to burning oil, coal and methane gas, is causing hotter temperatures to become more frequent” in places such as the Ivory Coast, Ghana, Cameroon and Nigeria.
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 32C (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 32C 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 32C on at least 42 days across two thirds of the areas analysed.
Researchers said “excessive heat can contribute to a reduction in the quantity and quality of the harvest”.
Many other factors were potentially harming cacao trees and boosting prices, they noted, including mealybug infestations, rainfall patterns, smuggling and illegal mining.
Christian Aid published separate research this week on the vulnerability of chocolate and cacao farmers to weather changes driven by global heating.
The UK charity said conditions in west Africa had changed dramatically due to extreme rainfall and spoiled crops during the dry season in 2023 and the drought in 2024.
“Growing cocoa is a vital livelihood for many of the poorest people around the world and human-caused climate change is putting that under serious threat,” said Osai Ojigho, the director of Christian Aid’s policy and public campaigns.
Failed harvests had helped drive a significant rise in cocoa prices since late 2023 on the London and New York markets where the commodity is traded.
New York cocoa prices were more than $10,000 a tonne on Wednesday, below a peak of more than $12,500 in mid-December. New York prices have largely hovered between $2,000 and $3,000 a tonne for decades.
In January, the Swiss chocolate maker, Lindt & Sprüngli, said it would raise prices again this year to offset rising cocoa costs.
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.
