We're never happy with what we have. But excessive consumption is damaging our planet. Could greed lead to the collapse of the climate as well as our society?

From Buddhists and bankers to Eskimos and psychologists, we explore the phenomenon of greed with people from all walks of life. How can it be defined? What makes us greedy? And what are the repercussions?

People like to have a lot of stuff because it gives them the feeling of living forever," says American social psychologist Sheldon Solomon. He thinks we have to come to terms with our own mortality before we can break the cycle.

Are there other ways to feel happy and content? Can we simply stop being greedy by changing the way we think?