Coffee is in trouble. Even before the United States imposed tariffs of 50 percent on Brazil and 20 percent on Vietnam—which together produce more than half of the world’s coffee beans—other challenges, including climate-change-related fires, flooding, and droughts, had already forced up coffee prices globally. Today, all told, coffee in the U.S. is nearly 40 percent more expensive than it was a year ago. Futures for arabica coffee—the beans most people in the world drink—have increased by almost a dollar since July. And prices may well go up further: