How the human species treats the planet over the next one hundred years will determine the future of all life on Earth. We stand to lose up to 50% per cent of species on the planet if we continue using global resources at the current rate. At this crucial point in human history we can still choose whether future generations inhabit a healthy, diverse planet, or a seriously impoverished one. In the final film of this trilogy, David Attenborough looks for hope and solutions.