The Extended MACC (EMAC) Method
The Extended MACC (EMAC) method, proposed by Ponz-Tienda et al. (2016), also allows the direct and continuous ranking of both positive and negative cost measures, favouring those options with the lower cost and greater GHG reduction potential and giving priority to measures with negative total cost (ABm — ACm < 0) over greater reduction potential. The EMACm indicator exposed in Eq. 4 relates the inverse of the net present value of every measure (Costm = ABm — ACm), with the GHG abatement potential (AEm).
For positive cost measures, EMAC operates as the traditional MACC index, and for measures with negative costs, EMAC method prefers measures with greater cost effectiveness in the positive range (same as traditional MACC) and prefers measures with greater abatement potential and greater cost reduction on the negative side.
The Environmentalist (ENV) and the Greedy (GRE) Methods
The previously exposed methods rank abatement measures providing different ordered sets, some favouring measures with high environmental impacts, others favouring measures with high economical profit. These two new ranking methods (Ponz-Tienda et al. 2016) are “referential benchmarks” to establish the limit bounds under “environmentalist” or economical “greedy” attributes. In this way, the environmentalist (ENV) method ranks the abatement measures considering only the GHG abatement potential (Eq. 5), hence, it is the “environmentalist” ranking bound. On the other hand, the greedy (GRE) method (Eq. 6) orders the measures solely based on total cost of the measure (Costm), as the difference between ACm and ABm, hence, it is the “greedy” ranking bound.