Tier 1 Default emission factor (IPCC 1996 guidelines)
AD = country data or international driver
EF =IPCC default value
Tier 2 Country-specific emission factor
AD = country data
EF= country specific
Tier 3 Specific emission factor (fuel and technology used) Specific methodology used
AD= country data disaggregate by types
EF = country specific disaggregate by activity data types
Specific model use