A treaty banning all mining and mineral exploitation in the Antarctic finally comes into force on Wednesday more than six years after it was agreed at an international conference. The Antarctic Environmental Protocol outlaws mining for 50 years, establishes strict limitations on pollution and waste disposal, and stipulates measures to protect flora and fauna. James Schofield reports:

The treaty is intended to save an area twice the size of Australia for the advancement of science and the welfare of its wildlife. Antarctica covers one- tenth of the world's land surface.

It's the largest area on Earth ever to receive protection from industrial development. But securing international agreement to the treaty has taken rather longer than expected.

Signed in Madrid six years ago, the Environmental Protocol has become effective only now, after ratification by Japan - the last of the 26 nations involved in the conference to do so.

While the protocol preserves the ban on mining and mineral exploitation and other restrictions for 50 years, it is generally considered unlikely the agreement will be overturned even at the end of that period.

The environmental lobby group Greenpeace described it as a milestone for global protection and a hopeful day for the planet. The treaty prohibits any activity relating to mineral resources in Antarctica other than research - but it's meant to be flexible as well.