Effects of international trade of food and feed and human diet shifts on food security and environmental safety: integrating scales

Abstract

*International trade of food and feed (expressed as protein content) has increased eightfold during the last 50 years. Nowadays a small number of countries are feeding the rest of the world. Population growth but also a change to higher animal-protein diets are important drivers of the observed changes. *The increasing disconnection between crops (land) and livestock is producing a decrease in nutrient use efficiency at the global scale and a rise in pollution issues. *In Spain, a transition from the so-called Mediterranean diet to a diet with very high share of animal protein that is similar to North American and North European diets, that are much unhealthier, is the main driver of a dramatic increase in the nitrogen (N) pollution. The huge production of animal products is fuelled by feed imports that today equal national crop production. *Despite Spain produces commodities for export, the net balance of N2O emissions of the agricultural system in 2009 indicated that the emissions associated to the production of imported food and feed are higher. A large part of the net N2O emissions associated with imported agricultural commodities is coming from non-Annex B countries and therefore substantial emission leakage is occurring. *Making the most sustainable use of crop by-products is not necessarily incentivised by policies on agricultural commodity markets, which may have a remarkable and undesired effect on the carbon footprint of livestock products (e.g. milk). *Localization of vegetal and animal production, the reduction of food waste, as well as control of diet, are key factors for world food security and environmental safety. *Less intensive farming could be viable if nutrient losses along the food chain are sharply decreased and human diet shifts are also occurring. Linking appropriately policies that deal with food, agriculture, waste, health, climate change, biodiversity and energy are needed to effectively reduce greenhouse gas (GHG) emissions globally.