Raphaël Trotignon

Combining cap-and-trade with offsets: lessons from the EU-ETS

Linking a cap-and-trade with an offset mechanism has many theoretical advantages: it reduces compliance costs, extends the price signal outside the cap-and-trade, and triggers technology transfer. However, it is feared that such linking will induce outsourcing of emissions reduction at a low price and undermine the price incentive in the cap-and-trade. The EU Emissions Trading Scheme (EU ETS) is the first full-scale example of a cap-and-trade system linked to project-based mechanisms such that offsets have effectively been used by industrial installations. This article is an ex post analysis of EU ETS data for the years 2008 and 2009, and the characteristics of the link and its efficiency are evaluated. Although offsets have been much used, their use is concentrated and not very intense or frequent, which allays the fear that offsets will flood the market. Although the majority of surrendered CERs effectively come from the largest and oldest projects, the credits surrendered are similar to those available on the market. Possible factors that contribute towards inefficiency are the rules for using offsets, transaction costs affecting the participation of small installations, awareness and openness to market-based instruments, and uncertainties regarding CERs offer and demand from other markets. However, the impact on EUA equilibrium price still needs to be quantified.