If we want to understand the present state of the world, we could possibly start by looking at it from outer space: we would see a small, blue and green planet. Seven billion people currently inhabit this planet, and if you were to get close enough to see the lights at night, you would realize to what extent these people are concentrated in major urban agglomerations, mostly along the coast of its seven seas.
Today, with a world population reaching levels never seen before, population projections suggesting considerable growth going forward, and greater prosperity for an ever-larger share of this population, the question of resources quite naturally comes up.
Indeed, if everyone on the planet were to adopt an average U.S. lifestyle, and if we are unable to change the way we currently use our resources, we will need the equivalent of four Earths. It thus becomes imperative to address questions of