Cumulative effects in SEA of spatial plans - evidence from Italy and England

Addressing cumulative effects (CE) has been widely recognized as a key purpose of strategic environmental assessment (SEA). In EU member states, the assessment of CE in SEA is prescribed by the SEA Directive. This paper investigates whether and how CE are currently treated in SEA of Italian and English spatial plans. This is based on the results of (1) a questionnaire survey and (2) a systematic review of SEA reports of local and regional Italian and English spatial plans. It is found that, opposite to what even some experts think, while CE remain unsatisfactorily addressed, there is ample space for improving current practice. In this context, better scoping, future-oriented approaches to SEA and more effective tiering are identified as key elements that can enable more effective CE assessment.