An article in Science argues we can’t accept agriculture in its present form.

J. P. Reganold et al.

Agriculture in the United States and many other countries is at a critical juncture. Public investments and policy reforms will inform landscape management practices to be used by farmers and ranchers for sustaining food and ecosystem security. Although U.S. farms have provided growing supplies of food and other products, they have also been major contributors to global greenhouse gases, biodiversity loss, natural resource degradation, and public health problems (1). Farm productivity and economic viability are vulnerable to resource scarcities, climate change, and market volatility (2). Concerns about long-term sustainability have promoted interest in new forms of agriculture that (i) enhance the natural resource base and environment, (ii) make farming financially viable, and (iii) contribute to the well-being of farmers, farm workers, and rural communities, while still (iv) providing abundant, affordable food, feed, fiber, and fuel.
http://www.sciencemag.org/cgi/content/summary/332/6030/670