The Hemileia vastatrix fungus, “roya” or “coffee rust,” can be devastating when conditions are especially favorable for rapid growth. The coffee rust has increased in 2015 mainly due to climate change. The economic impact is over $2.5 billion per year, along with over 500,000 jobs lost in Costa Rica and across Central America, and an increase of illegal immigration to the USA.
"Coffee rust has increased in 2015 mainly due to climate change."
The economic impact: In Mexico and Central America coffee yields have dropped in production between 30 to 80%.
Instead of developing properly, the “cherries” which produce the coffee beans stop growing. If they’re already ripening, the rust turns them from scarlet to grey.
Coffee rust likes warm, wet conditions and flourishes in rain and heavy dew. Arabica plants are particularly vulnerable, which is disastrous for Central America, because Arabica accounts for almost all the production.
The past five years have been a struggle for many small farmers there. Rising temperatures resulting from climate change are fuelling the growth of rust. In the hills above 1,000 meters where coffee is traditionally grown, cold nights and drier weather used to be a defense against the disease, but now the temperatures don’t drop so far at night.
The Global Warming Effect
The dry season would normally kill off the fungus too, but it’s been extremely wet, for example, in 2011/12. A researcher, Jacques Avelino and his team, writes: “… in our opinion, meteorological anomalies were crucial to the epidemic’s development. The rainy season started earlier than normal in 2012 in Central America, probably inducing the onset of an early coffee rust epidemic.”
Farmers have stated that, in recent years, the weather has become hotter, wetter and less predictable. The Global Climate Risk Index names Honduras as one of the three countries most affected by extreme weather in recent years. Honduras declared coffee rust a national emergency in 2013. Coffee plots are only expected to start producing normally again in 2015/16.
More recently, chronic drought is causing havoc, according to Oxfam, as the rains fall later, forcing farmers to postpone their planting. A further problem is soil quality. Poorer farmers often cannot afford to make good the depletion of nutrients over time. Struggling plants, with weak immune systems, become more vulnerable to disease.
Organizations are stepping in to assist local farmers but these are symptomatic fixes that over time will be ineffective. The global solution is to collectively reduce green house gases and slow future climate change. The implications of this might be that coffee becomes a luxury item and not a stable.
Posted on: 2016-03-30 3:11 PM 
