Cost of greenhouse gas mitigation - comparison between TIMER and WorldScan

Comparison between TIMER and WorldScan

The TIMER (Targets IMage Energy Regional) model is a bottom-up model with detailed information on the world energy system and specific mitigation technologies. WorldScan can be classified as a top-down Computable General Equilibrium (CGE) model of the world economy that focuses on the sources of growth and international trade. To be able to explain and interpret differences between the outcomes of these models and exploit their complementary insights, a comparison was made between them, for both the potential reductions and estimated mitigation costs for energy-related CO₂ emissions in various regions, for various levels of carbon tax.

The strengths of TIMER mainly concern the analysis of technology-specific development, including ‘learning by doing’ and physical constraints. By taking inertia in the energy system into account, TIMER has projected substantially smaller emission reductions for Russia and China than WorldScan, which indicates that WorldScan was too optimistic about the mitigation potential in countries that had recently expanded their energy production sector.

By taking into account the indirect effects of climate policies and their consequences for international trade, the strengths of WorldScan are mainly in the analysis of changes in the demand for goods and services, as a result of climate policies, and the redistribution of costs over sectors and regions. In particular, in regions with previously no taxation or with low tax rates, WorldScan estimated substantial emission reductions, achieved through changes in the volume and structure of production, which are not considered by TIMER.

Complementary models

In cost assessments of climate policies, results by WorldScan complement the analyses made by TIMER, in particular with respect to the regional distribution of those costs. This effect will be even greater in analyses on climate coalitions that do not include all countries in the world. Moreover, analyses by WorldScan require a complementary assessment by TIMER on the technological aspects of the changes in the energy system. Exploiting the complementary insights of both models will provide a set of models that is very well suitable to assess the various impacts of climate change policies.