Development of estimating method of global carbon, nitrogen, and phosphorus flows caused by human activity

In this study, we developed a method of estimating global carbon, nitrogen, and phosphorus flows caused by human activity. To describe these flows, we propose Global Carbon, Nitrogen, and Phosphorus Account Tables (GCNPAT). In order to estimate these flows, we used input-output tables, trade statistics and various industrial production statistics as the input data. In addition, we developed a calculation method based on material balance approach, coupled with a concept of “material density”. The material density is defined as the weight of the material included in commodities of one monetary unit. This calculation method is to estimate consistent values with related statistics of sector's and countries' productions and also trade flows. We estimated the year 2001 tables to demonstrate our method. The results showed that humankind took 13,392 Tg of carbon, 248 Tg of nitrogen, and 29.2 Tg of phosphorus from the environment in 2001.