The major causes of global environmental changes are various anthropogenic activities, not only those of present but also the integrated past activities. However, the interaction between man-environment system has not been understood sufficiently. The previous studies of monitoring of ongoing global environmental changes have paid little attention to socio-economic dimensions of anthropogenic activities which have induced various types of serious environmental changes. Land use forms a major element of terrestrial ecosystem modified by man and there is a growing concern in its disastrous change. In the above context, the emerging Remote Sensing and Geographic Information System help to strengthen the capacity of existing national and sub-regional institutions in the management and access to delivery of environment and natural resources information and data to support decision making process. Building effective bridges between scholars from various parts of the world is one of the most important tasks in this context. Increasing co-operation between researchers from advanced industrial nations and Third World countries is of particular importance. In order to achieve these goals, the International Geographical Union organized an International Seminar on Monitoring Geosystems - Perspectives for the 21st century, at University of Delhi during December 6-9, 1991. The contributed papers were modified and updated. The present volume includes 26 contributions dealing with concepts and methods, related to global environmental change.