"In light of all these hurdles, as I see it, the challenge is to double world food output by 2050 using less land, far less water and fewer nutrients – all in the teeth of increasing rates of drought. And we need to do it sustainably."

"I believe we are quite capable of solving these issues through good science and good policy. In the first instance, we need to massively increase global public investment in agricultural research and development. Then we need to make sure the fruits of that research reach farmers everywhere. I also think that commercial wild harvests, such as fishing and forestry, should be phased out in favour of sustainable farming that dovetails with the local environment."