Millions of farmers grow robusta coffee around the world, supplying nearly 40% of the world’s coffee – second only to the arabica bean.
As part of the ‘De Risk South East Asia’ collaboration project with the World Meteorological Organisation and the International Centre for Tropical Agriculture, USQ researchers are looking at ways to increase the resilience of agricultural producers in the region, including the impact of climate change on coffee growers.
Dr Jarrod Kath from USQ’s Centre for Applied Climate Sciences said the project used a decade of yield observations from nearly 800 robusta coffee farms across South East Asia in conjunction with rain and temperate data to find the perfect temperature range for peak production.
“Robusta is a common crop in South East Asia due to its heat tolerance and has always been considered to be the most resistant coffee crop to grow for tolerance against the elements” he said.
“When we started studying the data, we found that the crop actually performs best at an average temperature of 20.5 degrees Celsius, which is much lower than the assumed optimal range of 22-28 degrees Celsius.
“We could then see a pattern emerging, showing that for every one degree increase above 20.5 degrees, there was a corresponding decline in yield of around 14 per cent. This suggests that robusta coffee is far more sensitive to temperature than previously thought, and so possibly far more susceptible to the impacts of climate change.”
Dr Kath said the findings have significant ramifications for coffee production as temperatures increase under climate change, that will have flow on effects to the livelihoods of millions of farmers around the world.
“The socio-economic consequences in South East Asia could be substantial as temperatures continue to rise,” he said.
“Vietnam is the second largest coffee producer in the world. Millions of people in Vietnam, including many vulnerable farmers, derive a large part of their income from coffee, and a lot of that coffee ends up in our instant coffee here in Australia.
“The results definitely suggest that globally there needs to be some thought given to how best manage the impacts of hotter temperatures on coffee production into the future.”