The greenhouse gas metric works on a per-product basis, whereas in contrast the biodiversity metric is for whole-farm. A whole-farm assessment is a GHG emission inventory considering all aspects that may influence the overall footprint of a farm/business including arable land etc., while the current CFT does a product carbon footprint. E.g. forest areas belonging to the farm may have an impact on the company’s carbon footprint, but will not impact the product carbon footprint itself (also GHG Protocol standards differentiate between company and product footprints).
We recognise the potential benefits that exist from taking a whole farm perspective, but these are not readily modelled to allow simple user data entry. However, the Tool does already account for cover crops used in rotation, as well as factors such as land use change and trees on the land.