A study published Monday in the journal Philosophical Transactions of the Royal Society B debunked reports that climate change is responsible for a plant fungus that devastated coffee crops in Colombia.
“Media reports have linked coffee leaf rust — also known as CLR or roya — with climate change, but the new research finds ‘no evidence’ for this,” an article published Monday in the Science Magazine stated.
The study titled, “Modelling coffee leaf rust risk in Colombia with climate reanalysis data,” stated: “We focus particularly on Colombia, one of the world's largest coffee producers with around one million hectares under cultivation, primarily of the high-value species. CLR is endemic to the centre of origin of coffee in Ethiopia, but has spread to all coffee-growing regions, reaching Brazil by 1970, and Colombia by 1983.
“Since then, CLR damage has varied among countries and from year to year. Mean annual production in Colombia is around 60 000 tonnes, which declined by around 40% from 2008 to 2011, increasing again thereafter,” the study stated.
Researchers tested the hypotheses “that (i) the weather was responsible for a recent outbreak of CLR in Colombia and (ii) that climate change increased the probability of weather conditions favourable to CLR.”
“While CLR infection risk was elevated in 2008–2011 in coffee-growing regions of Colombia, we found no compelling evidence for a large increase in predicted infection risk over the period in which the CLR outbreak is reported to have been most severe, and no long-term trend in risk from 1990 to 2015,” the study concluded.
“Therefore, we conclude that while weather conditions in 2008–2011 may have slightly increased the predicted risk of CLR infection, long-term climate change is unlikely to have increased disease risk,” it added.
“We found a decline in mean daily LWD from around 2012–2015 and a resulting decline in daily CLR risk, suggesting that weather conditions have become less favourable for CLR in recent years. It is possible that this drying helped to bring the epidemic to a close,” the study found.