GHG emission intensity parameters

Table of contents

This document describes the emission intensity coefficients that are used in models that include generation of Greenhouse Gases (GHGs) from production processes (each of the inputs as well as the processes associated with output) and from consumption by households and government.

GHGs in G-Cubed

Four different greenhouse gases are accommodated by the versions of G-Cubed models that provide a full articulation of GHGs. These are:

  • Carbon dioxide (CO2)
  • Methane (CH4)
  • Nitrous oxide (N2O)
  • Fluorinated gases (F-gases)

The various gases are introduced into the model in CO2-equivalent terms. The CO2-equivalent emissions are calculated by multiplying the emissions of each gas by its Global Warming Potential (GWP) factor. The GWP factors are taken from the IPCC’s Sixth Assessment Report (AR6).

Emission drivers

Emissions of each of the four gases are associated with:

  • Household consumption
  • Government spending
  • Production by firms

The emissions associated with production by firms are further disaggregated into emissions that scale with:

  • the value of other intermediate goods in the production process
  • the value of labor in the production process
  • the value of capital in the production process
  • the value of output generated by the production process

Emission intensities

Scaling factors are required to determine the gas emissions generated by each of these economic activities. These scaling factors are referred to as emission intensities.

For each of the four gases:

  • For households, each region has an emission intensity for each of the goods consumed.
  • For government spending, each region has an emission intensity for each of the goods that the government purchases.
  • For each sector in each region there is an emission intensity for:
    • each of the intermediate goods that are produced
    • the labor used in production
    • the capital used in production
    • the output generated by the production process

These emission intensities are calibrated using the information about emissions and economic activity in the base year of the database. In turn, those intensities reflect the intensities embodied in the GTAP data in the GTAP reference year.

Sector input emission intensities

  • sector_input_emission_intensity(gases,goods_oc,sec_std,regions) captures the emission intensity for each type of gas by the sector for the given good when used as a factor of production. Note that it excludes durable manufacturing goods because they are not variable factors of production.

  • parameter sector_labor_emission_intensity(gases,sec_std,regions) captures the emission intensity for each type of gas by the sector for the labor used in production.

  • parameter sector_capital_emission_intensity(gases,sec_std,regions) captures the emission intensity for each type of gas by the sector for the capital used in production.

  • parameter sector_output_emission_intensity(gases,sec_std,regions) captures the emission intensity for each type of gas by the sector and associated with its output but not already accounted for by association with factors of production (inputs).

  • household_emission_intensity(gases,goods_oc,regions) captures the household consumption emission intensity for each type of gas and each type of good consumed (excludes non-durables).

  • government_emission_intensity(gases,goods_oc,regions) captures the government consumption emission intensity for each type of gas and each type of good consumed (excludes non-durables).