The OECD methodology takes the emission data from the national greenhouse gas inventories submitted under the United Nations Framework Convention on Climate Change (UNFCCC) as a starting point. The emission data in the inventories are allocated to ISIC rev. 4 industries and households using the correspondence table proposed by Eurostat.

When the correspondence table requires the allocation of an inventory item to more than one industry, the OECD opted for using an allocation method based on output data since output closely correlates with emissions. Specifically, the allocation from one inventory to more-than-one industry is made according to the output share of each industry relative to the total output of those industries involved in the split.

Data refer to total emissions of carbon dioxide (CO₂ emissions from energy use and industrial processes), methane (CH₄ emissions from solid waste, livestock, mining of hard coal and lignite, rice paddies, agriculture and leaks from natural gas pipelines) and nitrous oxide (N₂O emissions) for greenhouse gas (GHG) emissions.

More detailed information available in the working paper "Towards global SEEA Air Emission Accounts".

2) Households
Households' activities are broken down using the COICOP classification (http://unstats.un.org/unsd/cr/registry/regcst.asp?Cl=5)