Rice cultivation is deeply rooted in the Vietnamese culture. And so is the habit to burn the rice plant waste after every harvest. In Vietnam about 20 million tons of rice straw go up in smoke each year. That’s bad news for the environment, because the burning releases toxic greenhouse gases, but it’s also unhealthy for the Vietnamese because every harvest season they breathe in that smoke. Trang Tran, a social entrepreneur from Vietnam, is hard at work offering Vietnamese farmers an alternative to burning their straw: she’s teaching them to use the straw as a nourishing base for mushroom cultivation. If the farmers succeed in growing mushrooms several times a year in their straw, they can sell those to Tran’s company, thus doubling their income.