Tyrannosaurus rex, an animal to spark the imagination for all of us. What kind of an animal was it? What did it look like? How did it live? Now, scie… - David Attenborough

I can't pretend that I got involved with filming the natural world fifty years ago because I had some great banner to carry about conservation - not at all, I always had a huge pleasure in just watching the natural world and seeing what happens. - I made those films because it was a hugely enjoyable thing to do. But as I went on making them it became more and more apparent that the creatures that were giving me so much joy were under threat. The fun is in delighting in the animals but if you do that you owe them something so you have an obligation to speak out and to do what you can to protect them. m3s08-m4s05

Three and a half million years separate the individual who left these footprints in the sands of Africa from the one who left them on the moon. A mere blink in the eye of evolution. Using his burgeoning intelligence, this most successful of all mammals has exploited the environment to produce food for an ever-increasing population. In spite of disasters when civilisations have over-reached themselves, that process has continued, indeed accelerated, even today. Now mankind is looking for food, not just on this planet but on others. Perhaps the time has now come to put that process into reverse. Instead of controlling the environment for the benefit of the population, perhaps it's time we control the population to allow the survival of the environment.

Our imprint is now truly global. Our impact now truly profound. Our blind assault on the planet has finally come to alter the very fundamentals of the living world.