Decision support for international climate policy – The PRIMAP emission module

Abstract

Sound decisions in international climate policy depend on comprehensive and reliable emission data as well as accurate analysis and comparisons of policy proposals. In this context, the emission module of the Potsdam Real-time Integrated Model for the probabilistic Assessment of emission Paths (PRIMAP) has been developed. This article describes its design and functionality. The emission module allows for the flexible combination of data sources contained in its custom-built database into composite datasets, and the calculation of national, regional and global emission pathways following various emission allocation schemes. The resulting emission pathways can further be used to determine atmospheric CO 2 concentrations and temperature probability distributions using the PRIMAP climate module, which currently incorporates the reduced complexity climate and carbon-cycle model MAGICC. In addition to the calculation of emission pathways, the PRIMAP emission module supports analysis of policy options, like the quantification of different land use, land-use change and forestry (LULUCF) accounting provisions for Annex I countries. We discuss three applications of the PRIMAP emission module. In a bottom-up approach, we implement the pledges from the Copenhagen Accord, the announced developed country emission targets, in which provisions from LULUCF are taken into account. For the derivation of developing country emission pathways two different approaches are applied: capped per capita emissions and equal cumulative per capita emissions at average developed country levels. As a third example we implement a top-down approach, which equalises cumulative per capita emissions in a global emission pathway to achieve the 2 °C target with a likely (greater than 66%) probability.