Q.What is the 'Precautionary Principle' in environmental policy?

The Precautionary Principle says that uncertainty about the exact scale of environmental harm is not a valid reason to delay reasonable preventive action, particularly where the harm could be irreversible. …

The Precautionary Principle states that where an activity raises a credible threat of serious or irreversible environmental damage, the lack of full scientific certainty about the precise extent or mechanism of that harm should not be used as a reason to postpone taking reasonable, cost-effective measures to prevent it.

The principle exists because some forms of environmental harm — the extinction of a species, the crossing of a climate tipping point, the contamination of a groundwater aquifer — cannot be reversed once they occur, and waiting for conclusive scientific proof before acting may mean acting only after the damage is already done and irreparable. The principle therefore shifts the practical burden toward earlier, precautionary action in the face of a plausible (even if not fully proven) risk of serious …

Students sometimes confuse the Precautionary Principle with the Polluter Pays Principle — the Precautionary Principle is about acting BEFORE harm is fully proven or has occurred, while the Polluter Pays Principle is about …