OverseerFM estimates greenhouse gas (GHG) emissions for the farm. These are presented as individual emissions per source (e.g. enteric methane per enterprise, N2O from N fertiliser) and emissions per enterprise or area.
Because Overseer is a farm scale model, the modelling accounts for all direct and embodied GHG emissions up to the point that the product is ready to leave the farm for processing. This includes embodied emissions of feeds and fertiliser brought into the farm and the emissions of the activities undertaken on farm.
The paper GREENHOUSE GAS FOOTPRINTING USING OVERSEER® – ‘THE WHOLE PICTURE’ David Wheeler, S Ledgard and M Boyes (2011) describes the methods used to allocate total farm GHG emissions to a product footprint and to calculate the farm emissions on an area basis.
Updated emissions factors were released in Overseer Version 6.3.3 and can be found from Page 6 of the release notes.