Abstract
The global warming potential GWPgas(H) relates radiative forcing of a single pulse emission of a greenhouse gas, the absolute global warming potential AGWPgas(H), to the respective radiative forcing of carbon dioxide over a defined time horizon H. Mitigation measures targeting short-lived climate forcers (SLCFs) or reversible measures need to be applied permanently to be effective in the long run, but cost effectiveness for a permanent application of a measure differs from a single application. We propose a concept for an absolute global warming potential of permanent yearly pulses AGWP’gas(H), and several options for alternative indices to replace or complement the GWP: For the GWPgas(H/H) and the GWPcgas(H/H) we keep the AGWPCO2(H) in the denominator, which allows the direct comparison with conventional estimates, while for the GWP’gas(H) we define a new metric replacing the denominator by the AGWP’CO2(H). Different cost-effectiveness indicators can be defined respectively. We demonstrate the concept on the example of typical greenhouse gases emitted or removed by the agricultural sector: methane, nitrous oxide and carbon dioxide, fossil and stored as soil carbon. We show that, compared to GWP-based cost-effectiveness analysis, measures targeting soil carbon are discouraged relative to measures targeting methane, nitrous oxide and fossil carbon dioxide.
Do greenhouse gas mitigation cost-effectiveness rankings based on the global warming potential favor sub-optimal allocation of resources?
