Please help me to understand the following definition of "Precautionary Principle"

for "precautionary princple", it gives the following definition.

where there are threats or serious or irreversible damage, lack of full scientific cerntainty shall not be used as a reason for postponing cost-effective measures to prevent envrionment degration.

I am having difficulty to understand this defintion. What does it mean??

Say I plan to build a pipe-line. If I am not certain about the envrionmental impact the pipe-line will bring to the community (or I can't provide full scientific certainty that it is not harmfull), then according to the "precautionary princple", I can go ahead and build it?

Solution 1:

The 1998 Wingspread Statement on the Precautionary Principle summarizes the principle this way:

When an activity raises threats of harm to the environment or human health, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.

All statements of the Precautionary Principle contain a version of this formula:

When the health of humans and the environment is at stake, it may not be necessary to wait for scientific certainty to take protective action.

So, if you want to build the pipeline, it is your duty to prove that it is safe, not our duty to prove it is a risk.

Read more here and also on Wikipedia