big industrial farmers are not going to stop until the ogallala aquifer is pumping air. [digital bleeps pulse] [digital bleeps fade] [percussive music builds] [chiwetel] brazil. the front line between nature and modern civilization. many believe that this is where the future of the world's climate will be decided. a frontier [gun clicks] where the idea of climate change ceases to be an abstraction. already, brazil is the world's ninth biggest economy. but economic development has come at a high price. the amazon is the biggest rainforest in the world. but in brazil, illegal logging has already reduced its size by almost a fifth. while the country's population doubled to over 200 million since 1970 the rainforest lost an area the size of texas. it is already possible to envisage an amazon without a rainforest. [speaking brazilian portuguese] there's more fresh water in brazil than anywhere on earth. but its biggest cities are being hit by drought. [crowd chants] water demonstrations in the streets, a sense that something in the climate is going wrong. and the growing awar

and it's being watered from the ogallala aquifer. as we speak. ogallala, of course, is our aquifer. and there was a time when water was just something we turned on the tap and we didn't even think about where it came from. drilled the wells around here, the attitude was there's enough water to last forever. 'cause it seemed like it when it was 200 feet deep and not that many people were pumping and, you know, "it'll last forever." they got plenty. this is a very large farm that i'm from. and my work really is to be ceo over about a dozen other guys that are specialists in their area. half the united states were farmers not all that long ago. farmer used to mean somebody who tilled the soil. and to me now a farmer is somebody is an economist. someone who makes a lot of decisions, someone who's specialized, and someone who is world-based rather than small-based. at 30,000, right now i'm farming close to 10% of the county. farming's gone from private to corporations. farming's gone from local, to regional, to national, to worldwide. we're in a worldwide market, worldwide supplies, worl