By Brandon Keim Wired June 11, 2013 A disease called coffee rust has reached epidemic proportions in Central America, threatening the livelihoods of hundreds of thousands of farmers and the morning pick-me-up of millions of coffee drinkers. Caused by a leaf-blighting fungus, possibly exacerbated by growing practices and climate change, the disease leaves coffee plants spindly and barren, their precious fruits unripened. “Where people have been using heirloom varietals for a century, you just have trees without leaves,” said David Griswold, president of Sustainable Harvest Coffee Importers . “We’re already into the flowering cycle now, then it takes nine months to incubate the beans. You can see from the flowering what the losses will be. It’s just twigs. It’s as though you’re walking through a forest of twigs.” The effects haven’t been felt yet among coffee drinkers in developed countries, but history gives a sense of the problem’s potential magnitude. Englan...