And when you get large numbers of people living in land that is not that fertile, particularly when you cut down trees, and you leave the soil open to the wind for erosion, as desperate populations cut down more and more trees, so that they can try and grow food for themselves and their families, what's going to happen? Something's got to give.
有大量的人 生活在不那么肥沃的土地上 尤其当你把树砍倒 使得土壤裸露，任风侵蚀 同时处于绝望的人砍倒越来越多的树 以便为他们自己和家人努力培育粮食 这样会发生什么？有些东西会开始牺牲让步