字幕表 動画を再生する 英語字幕をプリント >> BRUCE PENGRA: Well another one of the really big stories of environmental change is the deforestation in the Amazon. An interesting part of the story starts at the river a long ways to the north actually. If we zoom in here along the Amazon way up here in what looks like virgin forest still -- and a lot of it is -- you can see a road that leads from the Amazon here and along through more or less untouched rainforest for hundreds and hundreds of miles. And as you get south far enough you start to see clearing along the road where farmers are starting to clear the forests and farm. The road facilitates the farming, the road facilitates the population coming out there. And then all along that road the land is cleared and when there isn't any land next to the road another road is cut, often in another direction and people start clearing that. And progressively you get this fishbone pattern that expands and expands and grows together into things that look more like this. And the forest is just a handful of little scraps anymore that are scattered throughout between farm fields where it's either a low spot that swept or for some other reason isn't ideal to farm. Amazon basin deforestation is along an arc and the states of Rondonia, Mato Grosso, and Para and from 1999 to 2012 it's quite striking. This whole area here in Eastern Para state if you go back to 1999 the vast majority of it is intact forest and you can just see the herringbone roads come out through the forest and then roads come out from those and the land clearing and the forest disappearing. And it's made all the more obvious with these two protected areas here which don't disappear... makes it really quite compelling to see. As you look at this, these are... a lot of people called Amazon the lungs of the world. It's a little bit at a time when you're on the ground and you clear an area for soybeans and you can feed some people. But when you look at it in the bigger picture again as Landsat allows you to do you can see that it's not something we can do forever.