In 2014, the FAO published the report ‘Food wastage footprint: full cost accounting’. In close cooperation with the Swiss Agricultural Research Institute FIBL, a methodology was developed as to how one can calculate the external costs of food production.
It must be noted that the total cost of wasted food will differ for different product groups. Since the ratio of different product groups will differ for consumed food and wasted food, extrapolation of the global cost of waste to the global cost of food production will increase the margin of error.
However a more recent FAO report, "Natural Capital Impacts in Agriculture" from 2015, confirmed the number for environmental damage, evaluating the environmental costs of global agriculture to be over USD $ 2330 billion (USD $ 2.33 trillion) per year, which is near enough the earlier estimated USD $ 2100 billion.
These costs are not paid for at the grocery checkout counter, yet consumers today and future generations tomorrow will bear the brunt of this huge financial burden through taxes and healthcare costs.
Website FAO: www.fao.org
FAO report "Food wastage footprint: full cost accounting - 2014"
FAO report "Natural Capital Impacts in Agriculture - 2015"