1. Meaning: Sustainable development means that development should take place without damaging the environment, and that development in the present should not compromise with the needs of the future generations. 2. Resources are limited: Many resources such as crude oil, coal, minerals and ground water are non-renewable and exhaustible; at the present rate of consumption the world's crude oil reserves will last only a few decades, so their careful use is essential. 3. Example of ground water: Ground water is over-used in many parts of India - in agricultural regions like Punjab and western Uttar Pradesh, in the dry regions of Rajasthan and Maharashtra, and in many cities - and the water table has fallen alarmingly; if this continues, water for future generations will not be available. 4. Environmental degradation: Deforestation, air and water pollution, soil erosion and global warming caused by unplanned development threaten the life-support system of all living beings; e.g. the fall in the level of ground water and rising temperatures are affecting agriculture. 5. Consequences for the economy: Environmental degradation finally reduces the quality of life and the very possibility of further development, since resources are the basis of all production. 6. Conclusion: Since resources have to last for both the present and the future generations, and since environment is shared by all countries, sustainable development is essential for the survival and well-being of mankind.