• Desirable output

As a desirable output, we used the generation of electricity, measured in TWh, distinguishing whether the generation sources were based on fossil sources—oil, gas and coal—or non-fossil sources—nuclear, geothermal, solar, wind, biomass and waves—to capture the assumption of weak disposability between CO2 emissions and electricity generation through fossil sources. This strategy was used by Cherchye et al. [16] and Walheer [31] to isolate the emissions of three polluting gases, but the latter used electricity generation as a necessary input to produce CO2 emissions and GDP.
