Economics- and physical-based metrics for comparing greenhouse gases

A range of alternatives to the Global Warming Potential (GWP) have been suggested in the scientific literature. One of the alternative metrics that has received attention is the cost-effective relative valuation of greenhouse gases, recently denoted Global Cost Potential (GCP). However, this metric is based on complex optimising integrated assessment models that are far from transparent to the general scientist or policymaker. Here we present a new analytic metric, the Cost-Effective Temperature Potential (CETP) which is based on an approximation of the GCP. This new metric is constructed in order to enhance general understanding of the GCP and elucidate the links between physical metrics and metrics that take economics into account. We show that this metric has got similarities with the purely physical metric, Global Temperature change Potential (GTP). However, in contrast with the GTP, the CETP takes the long-term temperature response into account.