 One of the reasons for hope is the resilience of nature. So once you give the land a chance and you stop exploiting it and destroying it, then it's amazing how nature can take over that land once again and make it beautiful. But sometimes the land has been destroyed for too long, and in that case we have to plant trees. Gombi was part of the equatorial forest belt in 1960 when I began. By 1990 it was a little island of forest surrounded by completely bales. People struggling to survive. I knew then that if we didn't do something to help the people find ways of living without destroying the environment we couldn't even try to save the chimpanzees. But that's when I got involved with improving the lives of people, restoring the forests, and that spread to other African countries and then became a global mission. Re-greening the land means saving tropical forests, restoring forests where it's possible, and planting trees. And planting trees is something everybody can do, and that's why this trillion tree challenge is so important. We need to protect the existing forests. We need to try and restore the forest and the land around the forest that hasn't been degraded for too long, where the seeds and the roots in the ground can sprout up and once again reclaim that land and make it an amazing forest ecosystem. And then it's no good just popping the tree in the ground. You've got to look after it. So these programs work best when they're within a community where the community understands the importance of the trees and we look after the trees. What's important for people to realize, this is not a way of giving license to those people who are burning fossil fuel, to go on burning fossil fuel thinking, well as long as we plant trees it's okay, it's not okay. A single human being makes some impact on the world every single day. Those of us living in the more wealthy communities can choose the kind of difference we make. What do we buy? Where does it come from? How is it made? Did it harm the environment? Did it lead to cruelty to animals? Is it cheap because of child slave labor somewhere in the world? And so the problem is that before we can have the individual making these wise decisions which will lead to a better world there's a cumulative effort of millions and billions of people making ethical choices.