http://JUDIS.NIC.IN SUPREME COURT OF INDIA stated in A.P. Pollution Control Board’s case (supra) cannot be applied. In that decision it was noticed that inadequacies of science had led to the precautionary principle leading to the principle of burden of proof in environmental cases where burden as to the absence of injurious effect of the actions proposed is placed on those who want to change the present state of affairs. After detailed consideration of this decision, it is held in Narmada Bachao Andolan’s case (supra) :"It appears to us that the ’precautionary principle’ and the corresponding burden of proof on the person who wants to change the status quo will ordinarily apply in a case of polluting or other project or industry where the extent of damage likely to be inflicted is not know. When there is a state of uncertainty due to lack of data or material about the extent of damage or pollution likely to be caused then, in order to maintain the ecology balance, the burden of proof that the said balance will be maintained must necessarily be on the industry or the unit which is likely to cause pollution. On the other hand where the effect on ecology or environmental of setting up of an industry is know, what has to be seen is that if the environment is likely to suffer, then what mitigative steps can be taken to offset the same. Merely because there will be a change is no reason to presume that there will be an ecological disaster. It is when the effect of the project is known that the principle of sustainable development would come into play which will ensure that mitigative steps are and can be taken to preserve the ecological balance. Sustainable development means what type or extent of development can take place which can be sustained by nature/ecology with or without mitigation. In the present case, we are not concerned with the polluting industry which is being established. What is being constructed is a large dam. The dam is neither a nuclear establishment nor a polluting industry. The construction of a dam undoubtedly would result in a change of environment but it will not be correct to presume that the construction of a large dam like the Sardar Sarovar will result in an ecological disaster. India has an experience of over 40 years in the construction of dams. The experience does not show that construction of a large dam is not cost-effective or leads to ecological or environmental degradation. On the contrary there has been ecological upgradation with the construction of large dams. What is the impact on environment with the construction of a dam is well known in India and, therefore, the decision in A.P. Pollution Control Board case will have no application in the present case." [at pp. 727-728] Aspects Related to Conditional Clearance Before adverting to other issues, certain aspects pertaining to the preservation of ecology and development have to be noticed. In Vellore Citizens Welfare Forum v. Union of India, [1996] 5 SCC 647, and in M C Mehta v. Union of India, [2002] 4 SCC 356, it was observed that the balance between environmental protection and developmental activities could only be maintained by strictly following the principle of’ sustainable development.’ This is a development strategy that caters the needs of the present without negotiating the ability of upcoming generations to satisfy their needs. The strict observance of sustainable development will put us on a path that ensures development while protecting the environment, a path that works for all peoples and for all generations. It is a guarantee to the present and a bequeath to the future. All environmental related developmental activities should benefit more people while maintaining the environmental balance. This could be ensured only by the strict adherence of sustainable development without which life of coming generations will be in jeopardy. In a catena of cases we have reiterated that right to clean environment is a guaranteed fundamental right. May be in different context, the right to development is also declared as a component of Article 21 in cases like Samata v. State of Andhra Pradesh, [1997] 8 SCC 191, and in Madhu Kishore v. State of Bihar, [1996] 5 SCC 125. Page 7 of 37