Olivier Sassi

IMACLIM-R: a modelling framework to simulate sustainable development pathways

To assess the sustainability of future development pathways requires models to compute long-run Economy-Energy-Environment scenarios. This paper presents the IMACLIM-R framework, aimed at investigating climate, energy and development inter-related issues. The model was built in an attempt to address three methodological challenges: to incoporate knowledge from economics and engineering sciences, to support the dialogue with and between stakeholders, to produce scenarios with a strong consistency, concerning especially the interplay between development patterns, technology and growth. These goals led to the development of a recursive structure articulating a static general equilibrium framework including innovative features and sectorspecific dynamic modules now concerning energy, transportation and industry. This paper provides the general rationale of the model and the description of all its components.

The costs of climate policies in a second best world with labour market imperfections

This article explores the critical role of labour market imperfections in climate stabilization cost formation, using a dynamic recursive energy—economy model that represents a second-best world with market imperfections and short-run adjustment constraints along a long-term growth path. The degree of rigidity of the labour markets is a central parameter, and a systematic sensitivity analysis of the model results confirms this. When labour markets are represented as highly flexible, the model results are in the usual range of the existing literature; that is, less than 2% GDP losses in 2030 for a stabilization target at 550 ppm CO2 equivalent. However, when labour market rigidities are accounted for, mitigation costs increase dramatically. Accompanying measures are identified, namely labour subsidies, which guarantee against the risk of large stabilization costs in the case of high rigidities of the labour markets. This complements the usual view that mitigation is a long-term matter that depends on technology, innovation, investment and behavioural change. The results support the view that mitigation is also a shorter-term issue and a matter of transition with regard to the labour market.

How CO2 Capture and Storage Can Mitigate Carbon Leakage

Most CO2 abatement policies reduce the demand for fossil fuels and therefore their price in international markets. If these policies are not global, this price decrease raises emissions in countries without CO2 abatement policies, generating “carbon leakage”. On the other hand, if the countries which abate CO2 emissions are net fossil fuel importers, they benefit from this price decrease, which reduces the abatement cost. In contrast, CO2 capture and storage (CCS) does not reduce fossil fuel demand, therefore it generates neither this type of leakage nor this negative feedback on abatement costs. We quantify these effects with the global hybrid general equilibrium model Imaclim-R and show that they are quantitatively important. Indeed, for a given unilateral abatement in OECD countries, leakage is more than halved in a scenario with CCS included among the abatement options, compared to a scenario prohibiting CCS. We show that the main reason for this difference in leakage is the above-mentioned international fossil fuel price feedback. This article does not intend to assess the desirability of CCS, which has many other pros and cons. It just identifies a consequence of CCS that should be taken into account, together with many others, when deciding to what extent CCS should be developed.