In the past 10 years, the intensity of human activities has increased unprecedentedly. 2 1 At the beginning of the century, human activities once again set foot on the surface of Mars. In 2002, the global gross national product reached $24 trillion. The world economic development in 10 proves that all the development of intergenerational unfair resource utilization is at the expense of environmental damage. The original global environmental problems such as global warming, forest destruction, land desertification, soil erosion, marine pollution, pesticide pollution, water shortage and serious impact on biodiversity have not been alleviated, but have become more acute in some countries and regions. It is still the purpose of this book to improve the environmental awareness of human beings in an all-round way, especially the environmental awareness of future decision makers. Twenty years of teaching practice shows that this book meets the teaching requirements, so that the print run is increasing year by year. Therefore, the third edition of this book retains the original features of the 1 edition and the second edition, and at the same time adds new contents to adapt to the development of environmental science theory and practice. ..