Per a recent NY Times article: "Coffee yields have plummeted in Columbia and in many of Latin America’s other premier coffee regions as a result of rising temperatures and more intense and unpredictable rains, phenomena that many scientists link partly to global warming."
See the NY Times article for more information.
Details include: "In 2006, Colombia produced more than 12 million 132-pound bags of coffee, and set a goal of 17 million for 2014. Last year the yield was 9 million bags.
Brands like Maxwell, Yuban and Folgers have increased the retail prices of many grinds by 25 percent or more since the middle of last year in light of tight supply and higher wholesale prices.
Profits of high-end coffee chains like Starbucks and Green Mountain have been eroded. Coffee futures of Arabica, the high-end bean that comes predominantly from Latin America, have risen more than 85 percent since last June, to $2.95 a pound, partly over concerns about supply, extreme weather and future quality, said George Kopp, an analyst at the International Futures Group in Chicago."