The Role of Diet in Phosphorous Demand
A study conducted by researchers at McGill University, Canada, and published in the journal Environmental Research Letters, shows that changing diets have accounted for a 38% increase in the world’s per capita ‘phosphorous footprint’ between 1961 and 2007. Researchers analyzed annual country-specific diet composition data to calculate the amount of phosphorous applied to food crops. Their findings indicate that a sustainable supply of the essential mineral is in question.
Over the past 50 years, there have been major changes in human diets, including a global average increase in meat consumption and total calorie intake. We quantified how changes in annual per capita national average diets affected requirements for mined P between 1961 and 2007, starting with the per capita availability of a food crop or animal product and then determining the P needed to grow the product. The global per capita P footprint increased 38% over the 46 yr time period, but there was considerable variability among countries. Phosphorus footprints varied between 0.35 kg P capita−1 yr−1 and 7.64 kg P capita−1 yr−1. Temporal trends also differed among countries; for example, while China's P footprint increased almost 400% between 1961 and 2007, the footprints of other countries, such as Canada, decreased. Meat consumption was the most important factor affecting P footprints; it accounted for 72% of the global average P footprint. Our results show that dietary shifts are an important component of the human amplification of the global P cycle. These dietary trends present an important challenge for sustainable P management.
Citation as follows:
Metson, G.S., Bennett, E.M., Elser, J.J. (2012). “The role of diet in phosphorous demand.” Environmental Research Letters 7, 044043. DOI: 10.1088/1748-9326/7/3/044043.
While some of the food system challenges facing humanity are local, in an interconnected world, adopting a global perspective is essential. Many environmental issues, such as climate change, need supranational commitments and action to be addressed effectively. Due to ever increasing global trade flows, prices of commodities are connected through space; a drought in Romania may thus increase the price of wheat in Zimbabwe.