Increasing population combined with increasing standard of living and industrialization has resulted in use of natural resources of Earth at a rate faster than the ability of nature to renew or regenerated the resources so used up. Similarly the environment including air, water and land is being polluted at a rate much higher than the capacity of environment to cleanse itself. Thus the total way of life as it exists to day has become unsustainable.
This means that if we continue to deplete our natural resources and pollute our environment in the same way as at present, then a time will come when the Earth will no longer be able to provide the resources and environment essential for our present life style.Sustainable development refers to development of new technology and ways of living that can be sustained for ever.
Till about beginning of 20th century the problem of sustainable development did not receive much attention because of two reasons. First, the the adverse impact of human activities on the availability of natural resources and on environment was not understood that well. Second, the very high levels of standards of living and industrial activities witnessed today were not foreseen at that time.
As a result, in the past, we have made very indiscriminate use of our resources in our path of industrial development. But now, at the beginning of 21st century a critical stage has been reached, calling for urgent and drastic action to first stop further damage, and then reverse some of the damage already done.
We need to tackle issues such as global warming, finding alternative to non renewable energy sources such as petroleum and coal, finding way of eliminating pollution of land and water by non-biodegradable waste, protecting our flora and fauna, eliminating use of substances harmful to health in industries and products, and protecting further damage to our flora and fauna.