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Convert methane (CH4) and nitrous oxide (N2O) emissions to CO2-equivalents (CO2eq) using Global Warming Potentials (GWP) factors

Source: R/core_model_aggregation.R
calc_co2eq.Rd

Calculates CO2-equivalent (CO2eq) emissions for CH4 and N2O based on 100-year Global Warming Potentials (GWP) reported in IPCC assessment reports.

Usage

calc_co2eq(gas, value_allocated, global_warming_potential_set)

Arguments

gas

Character. Gas type for each observation. Supported values:

  • "CH4": methane (CH4)

  • "N2O": nitrous oxide (N2O)

  • "CO2": carbon dioxide (CO2)

value_allocated

Numeric. Allocated emissions for each commodity–emission combination (kg gas).

global_warming_potential_set

Character. Settings for the 100-year Global Warming Potential (GWP-100) conversion factors used to express CH4 and N2O emissions as CO2eq. Must be one of:

  • "AR6": IPCC Sixth Assessment Report (IPCC, 2021) — CH4 = 27, N2O = 273

  • "AR5_excluding_carbon_feedback": IPCC Fifth Assessment Report (excluding climate–carbon feedbacks) (IPCC, 2013) — CH4 = 28, N2O = 265

  • "AR5_including_carbon_feedback": IPCC Fifth Assessment Report (including climate–carbon feedbacks) (IPCC, 2013) — CH4 = 34, N2O = 298

  • "AR4": IPCC Fourth Assessment Report (IPCC, 2007) — CH4 = 25, N2O = 298

Value

List with elements:

value_co2eq

Numeric vector. Emissions expressed as CO2-equivalents (kg CO2eq).

gwp

Numeric vector. Global Warming Potential factor applied to each observation (kg CO2eq/kg gas).

Details

CO2-equivalent emissions are calculated as:

$$value\_co2eq = value\_allocated \times gwp$$

where gwp is the gas-specific 100-year Global Warming Potential factor from the selected IPCC assessment report.

This function is part of the run_aggregation_module().

References

IPCC (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.

IPCC (2013). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

IPCC (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.

See also

run_aggregation_module(),