Now we know that desertification is caused by livestock, mostly cattle, sheep and goats, overgrazing the plants, leaving the soil bare and giving off methane.
现在我们知道沙漠化是由家畜 多数是牛、绵羊和山羊等 过度放牧，吃光了植被， 使得土壤表面裸露出来并释放甲烷。