How Do You Spot a Trend? An Examination of Recent Phosphate Rock Production

Abstract

This work examines recent historical phosphate rock production and determines possible identifiable trends. The difficulties of identifying trends from short time-series are described. Statistical analysis alone cannot be definitive in identifying a trend. These results, however, can be supported by information about sources of increasing global demand. A bilinear model was developed that indicates global per-capita phosphate rock production was essentially steady from 1993 to 2006 at an average annual 22.58 kilograms per capita. Since 2007 there has been strong growth at an average annual rate of 5.1 percent per year. This, combined with a population growth rate of 1.14 percent per year, yields a growth rate in the total phosphate rock production of 6.3 percent per year. Even if further growth in per-capita production is linear at current rates and not exponential, total global phosphate rock production would have to increase by a factor of 3.6 to satisfy the demand by the year 2050. Whether such an increase would be expected to continue to this extent or not, this increase should provide motivation to begin the implementation of significant conservation measures. Underlying drivers of per-capita demand suggest that strong growth is likely to continue.