正如人们所熟知,环境的持续恶化及其对地球生命的危害已经成为21世纪亟待解决的最重要问题。事实上,它可能是人类有史以来所面临的最严重挑战。一如人们逐渐认识到的,环境问题总是以各种各样相互关联的形式出现,比如危及人类食物、水源和空气的污染;臭氧层空洞以及灭绝和濒危物 As is well known, the continuing deterioration of the environment and its damage to the life of the planet have become the most important issues to be resolved in the 21st century. In fact, it may be the most serious challenge humanity has ever faced. As one has come to realize, environmental problems are always manifest in a variety of interrelated forms, such as endangering the human food, water and air pollution; the ozone layer and the extinction and endangered