Explosive growth in the global demand for meat and seafood is changing the nature of food production and putting increasing pressure on natural resources throughout the world. Crop and livestock production operations are growing in intensity and scale, changing their location as a function of population growth and environmental regulation, and increasingly sourcing their inputs (such as feed) and sending their finished products abroad. These changes have important implications for environmental resources (e.g. water, nitrogen, and land), implications which are often hidden by the complex nature of global trade.