Narrator: This is Science Today. In early 2012, the world population reached the seven billion mark and by the year 2045, it's estimated that number will rise to about nine billion. Integrative biologist Anthony Barnosky of the University of California, Berkeley warns that this population growth may drive Earth towards an irreversible tipping point.
Barnosky: That's going to put additional stresses on how we produce and distribute energy, how we produce and distribute food, how we invest or use up natural resources. Think of the wheat belt in the central United States shifting north into Canada. All of a sudden, what we have depended upon for our economic prosperity suddenly is either no longer there or on somebody else's land.
Narrator: Barnosky is part of the Berkeley Initiative for Global Change Biology, or the BiGCB, which is working to come up with better predictive models to deal with biosphere change. For Science Today, I'm Larissa Branin.