An Earth Day ad released by the Californians for Population Stability focuses on population growth through immigration as a leading cause for the overcrowding, water shortage and traffic in the state.
But how accurate is this? Are large amounts of people in urban areas significantly affecting the planet in bad way? And how can we know the impact of one group of the population?
Dr. Ellen Percy Kraly is a professor at Colgate University who looks at population and the environment and joined us to talk about the many ways that people influence the earth.