This publication, Our Fragile World: Challenges and Opportunities for Sustainable Development, presents perspectives of several important subjects that are covered in greater detail and depth in the Encyclopedia of Life Support Systems (EOLSS). The contributions to the two volumes provide an integrated presentation of knowledge and worldviews related to the state of: Earth's natural resources, social resources, institutional resources, and economic and financial resources. They present the vision and thinking of over 200 authors in support of efforts to solve the complex problems connected with sustainable development, and to secure perennial life support on "The Blue Planet'. These contributions are holistic, informative, forward looking, and will be of interest to a broad readership. This volume presents contributions with focus on the Natural and Social Dimensions of sustainable Development in to two sections: NATURAL SYSTEMS AND RESOURCES (Natural Systems and Climate Change ; - Natural Resources Management). - SOCIO-CULTURAL ISSUES (Human Security, Peace, and Socio-Cultural issues; Equity and Ethical issues).