VIENNA (Thomson Reuters Foundation) - Banana trees that fit in a test tube. Burgers made without a cow in sight. Fish farmed in the desert. Robots picking fruit. Welcome to the brave new world of food, where scientists are battling a global time-bomb of climate change, water scarcity, population growth and soaring obesity rates to find new ways to feed the future. With one in nine people already short of enough food to lead a healthy, active life, supporters pushing for a Second Green Revolution argue without major changes hunger will become one of the biggest threats to national security...