Greenhouse Gas (GHG) Accounting can in itself be seen as a method, although no single standardised approach exists. While some state that it is the equivalent of a carbon footprint analysis, others acknowledge that it is not necessarily the same. For this report, a distinction is made between the two, where carbon footprint analysis is the assessment of total GHG produced, whereas GHG accounting is merely the inventorying of GHG emissions. The inventorying can be done according to a smaller, case study specific scope and can also include carbon sinks in the analysis, as opposed to only the emitting sources.

For the case studies of cities, some base their research on a simplified adaptation of the IPCC top-down method (Kennedy et al. 2010), while others apply a bottom-up method (Baldasano, Soriano, and Boada 1999).