The precautionary principle - recently added to the French constitution and part of the draft Constitution of the European Union - aims to protect the public from the risks associated with scientific and technological advance by allowing governments to ban any activity deemed to involve risks, even if those risks are unproven. In reality, the precautionary principle itself poses enormous risks of losing the advantages of projects that are banned, of preventing the development of the means by which risk may be ameliorated and of threatening the private property rights that provide the most effective environmental safeguard.