By Sarah Knapton – Re-Blogged From The Telegraph
Fears that climate change is triggering a coffee killing fungus which could wipe out plantations are unfounded, a new study suggests.
Last month a report by The Climate Institute warned that an increase in wet and warm conditions was driving the spread of coffee leaf rust which attacks crops, causing plants to wither and stop producing beans.
The experts warned that by 2080, coffee could become extinct if temperatures continue to rise.But a new study by the University of Exeter suggests that plantations are suffering due to a much more prosaic reason. Lack of funds.
They studied coffee plantations in Columbia where production fell by about 40 per cent between 2008 and 2011 because of severe outbreak of coffee rust
However Dr Dan Bebber, lead author, said that the crisis had been driven by the ‘perfect storm’ of weather coupled with a decrease in fertiliser use due to price rises during the 2008 financial crisis.
“Farmers weren’t treating coffee bushes as they normally would, and this was probably one of the factors that led to the rise in coffee leaf rust,” said Dr Bebber.
“The climate at the time was conducive to coffee leaf rust but there had been earlier periods of similar conditions when there wasn’t an outbreak.”
The team found there was ‘no evidence’ to link the outbreak of coffee leaf rust with climate change.
The 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.”
Dr Bebber and co-authors Sarah Gurr and Angela Delgado Castillo found that Colombian coffee yields had been highly variable over time due to varying weather, the effects of disease, management and socio-economic factors.
The team said more research was needed to fully understand the causes of the 2008-11 coffee leaf rust outbreak which caused hundreds of thousands of people to lose their jobs in coffee farms in Central America.
Temperature and leaf wetness are the most important determinants of infection risk for fungal plant diseases.
However there are other risks to coffee plantations if climate change continues unabated. A pest known as the coffee berry borer which is usually found in plantations below 1,500 metres above sea level is spreading upwards harming previously safe plantations.
On Mount Kilimanjaro in Tanzania the borer is now found nearly 300 metres higher than it was last century.
Around 120 million people in more than 70 countries across the globe depend on the coffee industry.