Value of decomposition figures in emission reduction policy analysis at international level - Report of a traineeship at RIVM

The case study concerns the reduction of NO_x emissions from combustion plants in industries in the Netherlands and Belgium in the 1985-1999 period. NO_x emission reduction policies have been studied and linked with the effect of NO_x emission abatement that is the technique effect in the decomposition analysis. Policy instrument characteristics have been used to describe the likely effect of studied instruments.

The case study shows that observed changes in the NO_x-technique effect in the Netherlands could be closely linked to specific policy events, such as the introduction and stepwise further improvement of the Dutch Decree on emission limits for large combustion plants (BEES). Hardly any technique effect was observed in Belgium in the period 1985-1999. On the condition that monitoring results of Belgium are reliable, this implies that no clear technical improvement in emission abatement of NOx has occurred in this period in industrial combustion plants in Belgium. This may be explained by the less ambitious emission regulation in Belgium i.e. emission standards are less stringent and the scope of action of the national regulation is more confined (less installations are regulated).

One of the most important conclusions of the case study is that decomposition analysis can play an important role in policy analysis. On the one hand, decomposition figures may confirm expected changes in emissions, and in doing so, underpin the results of policy analysis. On the other hand, changes observed in decomposition figures may indicate changes in policies, and in doing so, direct policy analysis. Finally, it may be concluded from the case study that the use of decomposition figures alone already gives a fair idea about the overall effectiveness of NO_x emission reduction policies in different countries. A broad-based and in-depth study as performed in this study produces more detailed knowledge but also requires much more effort. This time-consuming aspect has to be taken into account when considering and planning these kind of studies.