Down to Earth

As environmental analyst Lester Brown releases a new edition of his landmark blueprint for avoiding climate catastrophe –Plan B 4.0: Mobilizing to Save Civilization, he talks to Peter Day for this week's Global Business.

As we watch the Earth's climate changing at a pace that outstrips worst case scenarios from leading scientists, he says, we find ourselves in a race between political and natural tipping points on water depletion and climate change.

He tells Peter Day about his fears but also the signs he sees of opportunity.