Globalization has become one of the major and significant studies in international relations. It creates lots of effects to people in economy or other dimensions. However, the most serious and undesirable circumstance is that our ecological environment is changing on a large scale under the development of contemporary globalization. From the outcomes of various scientific researches and observations, the environmental degradation is becoming severe and, in the meanwhile, bringing the threats and challenges to human beings. This article tries to find out that, in the context of globalization, the factors that result in our environmental change, the adverse effects with the environmental degradation, international responses, and future challenges. In addition, this article attempts to remind people of the importance of environmental protection as well as our sustainable development on the earth.