What happens to civilizations when the food runs out? This happened in ancient Rome and to the Mayans, but can we take lessons from the past in order to have a more secure future?
A new book, "Empires of Food: Feast, Famine, and the Rise and Fall of Civilizations," looks at how food empires fail: when crops don't grow, the soil dries up, the climate shifts, and the population keeps growing and consuming more food than it can produce.
We're joined by the book's author to discuss this topic. Evan Fraser is a professor of geography who specializes in agriculture, and Andrew Rimas is a journalist and the managing editor of the Improper Bostonian.