The peak of her green interest was in the late 80s - a time of bubbling media coverage of acid rain, climate, waste and rainforest destruction.

BBC: Margaret Thatcher: How PM legitimised green concerns

Robin Lock is curator of the Eden project, a recreation of a rainforest in the West of England and has worked in rain forests around the world.

BBC: Congo rebel soldiers

With more than 20 feet of rain a year, these forests are as wet - and correspondingly lush - as a tropical rainforest.

BBC: Hiking through a microcosm of Earth