Wherever humans go, they leave trash behind. The average American throws away over 1,130 pounds of waste per year. On this week’s Please Explain, we continue our series How to Save the World, looking at how we dispose of garbage, how recycling and composting and smaller packaging can cut down on the amount of garbage people throw away around the world, and how garbage can be used as a renewable, green energy source. Joining us are Nickolas J. Themelis, Director, Earth Engineering Center, and professor in the School of Engineering at Columbia University, and Elizabeth Royte, author of Garbage Land and Bottlemania.