Below is a great TED talk that brings some awareness to what seems will be the most pressing issue of our time (in 10-30 years) as it is the prime contributor to our rapid resource depletion and increased risk of cataclysmic climate change.
I feel that economics is best for sorting out this problem. How best to get others to eat less in the more developed nations when high food costs prohibit people’s decision to over-consume. The same could be said of high costs of oil and decreased driving habits. Many pricing distortions that the modern economies experience directly impact the relatively cheap pricing of food; specifically water, fuel, and choice of production. (corn subsidies)
Although as much as economics has a benefit, there is a cost. Producers will be focused on maximizing gains by irrationally increasing output. (a la tragedy of the commons) This will drive already poorly productive agricultural producers to expand their output into valuable biodiversity resources such as the rain-forest.
The best solution IMO, would be to end the developed worlds price distortions in combination with aggressive conservation policies for the developing world that would limit our total % of land used for agriculture and offer appropriate support to help current fertile land gains to reach 90-100% of its maximum productive capacity.
The two should limit over-consumption while also promoting increased productivity.