This video from Farming First, a national coalition of sustainable agriculture organizations might seem overly simplistic, but watch it all the way through, the statistics about farming inefficiency and agricultural green house gases are issues that the global agricultural sector need to address.
Please enjoy and share this video, and consider the role that local farms near your home play in solving these crises, and also the role that small independent farms in the developing world play. When you have the choice between organic or fair trade coffee, chocolate, bananas, and other tropical products, consider that the extra cost is an investment in the farming techniques discussed in this video!
Also remember that if you had a yard, you can become a smale scale, sustainable agricultural producer. Here's the guide to being a climate friendly gardener: http://www.ucsusa.org/assets/documents/food_and_agriculture/climate-friendly-gardener.pdf start closing the food supply gap with yourself!
All the best,