As the climate changes and water becomes scarce in many parts of the world, growing enough food to feed the world's increasing population will be a challenge. Caleb Harper, a 2015 National Geographic emerging explorer, is working to solve this problem by using technology to reenvision the way we grow our food and move farms into the city. Imagine living in a world where food can be farmed from anywhere via a personal food computer, and your plants can send you a tweet when you're away to tell you how they're doing.