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.