English Abstract Decomposition analysis is a method for dis-entangling
the different key-factors that determine temporal changes in emission
levels. It is a 'top-down' method starting from general available
statistical data. This report explores the role decomposition diagrams can
play in national and international policy analysis and evaluation. For this
purpose a case study has been performed. The case study concerns the
reduction of NOx emissions from combustion plants in industries in the
Netherlands and Belgium in the 1985-1999 period. NOx emission reduction
policies have been studied and linked with the effect of NOx 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 NOx-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 NOx 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.
