Climate change has been wrongly blamed for devastating coffee plantations, a study has found.
Coffee leaf rust (CLR) caused coffee production in Colombia to fall by 40 per cent between 2008 and 2011. The decline was linked to the worst epidemic for several decades. A number of other coffee-producing countries in Central America and the Caribbean were also affected and hundreds of thousands of people lost their livelihoods.
The fungus appears as powdery orange spores that cause the leaves to fall off. It also reduces bean quality and makes the bushes vulnerable to other diseases. In badly affected areas, new bushes must be planted.
Some scientists linked the spread of the fungus to climate change because it thrives in higher temperatures and the moisture caused by increased rainfall.
The International Coffee Organisation, an intergovernmental body of coffee exporting and importing countries, said in 2014: “Due to changing climatic patterns, the fungus is expanding to higher altitudes where coffee is grown.”
Scientists at the University of Exeter took a different view. Their paper, published in the Royal Society journal Philosophical Transactions B, concluded: “We find no evidence for an overall trend in disease risk in coffee-growing regions of Colombia from 1990 to 2015, therefore, while weather conditions were more conducive to disease outbreaks from 2008 to 2011, we reject the climate change hypothesis.”