Humanity is facing its greatest challenge. To produce 70% more food by 2050 without destroying the environment means doing much more with less. Partly due to the abundant food and record-low food prices achieved by the Green Revolution, overseas development assistance for agriculture dropped...

Mining of energy resources and minerals is clearly the running down of a large but finite, and non-renewable, resource. It is important also to recognise the nonrenewable aspects of food production: in particular, net consumption of nutrients and soil as well as the direct and embodied...