Preface

Our planet Earth is the carrier and source for human survival. Currently, human are undertaking the struggle for protecting the Earth for their own survival. In the middle of the twentieth century, people felt anxious about the breakout of nuclear war. Since 1980s, however, the attention of the whole world has been transferred to the abnormal climatic changes, which led to starvation, and to the major pollution accidents occurred continually. This status is just the consequence made by natural retaliation upon human being owing to human's excessively drawing from the nature. From this reality, human have clearly recognized the significance: protection of the Earth is equal to protecting human's own survival.