This paper published in PNAS - Proceedings of the National Academy of Sciences of the United States of America - looks at the environmental costs of food production and in particular livestock based food production.  The paper is based on annual 2000–2010 data for land, irrigation water, and fertilizer from the USDA, the Department of the Interior, and the Department of Energy.

This study looks at the double challenge of increasing food security while addressing environmental problems caused by agriculture. It identifies a set of key actions in three broad areas that hold the greatest potential for achieving these efficiency and sustainability goals.

This study calculates and maps humanity’s green, blue and grey water footprint at a high spatial resolution.