Prior to conversion to agriculture, nearly all current croplands and a substantial amount of current pasturelands stored more carbon in their plants and soils than they do today. This implies a large “carbon opportunity cost” (COC) of agricultural production. The COC of agricultural land use is the total amount of carbon lost from plants and soils on land occupied by agriculture relative to native vegetation. Although the academic literature has analyzed COC on both a per-hectare basis and a per-unit-product basis, widespread use of the COC metric by companies and other entities has been limited by the lack of an easily accessible calculation tool. This freely accessible Microsoft Excel-based tool gathers spatial and statistical data on estimated native carbon stocks, agricultural carbon stocks, crop spatial distribution and yields, livestock feed efficiency and feed composition, and co-products into one place, automating the COC calculation. The tool includes default land occupation factors (yields) and COC factors per hectare and per tonne of product for nearly 90 common agricultural products across 10 regions and 5 countries. Users enter their own data on volumes of products produced or purchased (in kilograms), and the tool generates estimates of land occupation (in hectares) and COC (in carbon dioxide equivalent) for each product. Users may also refine the land occupation and COC estimates using their own data on carbon stocks and crop or livestock yields. This tool allows companies and other entities to calculate both land occupation and COC for reporting, target-setting, and decision-making purposes.

Update in June 2026

The Excel files were corrected on June 5, 2026, and include the following changes:

  • The global lookup values for “bioethanol from cereal straw,” which is not incorporated in this version of the tool, were deleted from line 1437 of the “Raw LO and COC data” tab from the calculation tool Excel file. 
  • The calculation parameters for “bioethanol from cereal straw,” which is not incorporated in this version of the tool, were deleted from lines 41-49 of the “Table A-13” tab from the Appendix Excel file.