clipped from www.treehugger.com

In 2008, global food demand is testing the capacity of petroleum-dependent, export-focused commodity agriculture. This system has not served developed nations as food prices soar—inflamed by biofuel demand and fuel prices—and has especially hurt developing nations already struggling with food security issues. The modern-farming paradigm has also resulted in nutrient overload in our waterways from the use of synthetic nitrogen, degradation of our soils and animal health and welfare concerns. Most disturbing is modern agriculture's contribution to global warming.

New data from U.S. government research shows that with agriculture using chemical fertilizers and herbicides, the U.S. food system contributes nearly 20 percent of the nation’s carbon dioxide emissions. On a global scale, figures from the Intergovernmental Panel on Climate Change (IPCC) say that agricultural land use contributes 12 percent of global greenhouse gas emissions.