Long-term time scales and infrequent events

Significant time lags may exist between adaptation interventions and measurable outcomes and impacts. Particularly in the case of projects focusing on long-term time frames, their success will not be apparent for years after the end of the project lifetime. The evaluation of interventions designed to deliver long-term benefits must be based on the assessments of proxy measures which may be difficult to identify. For projects designed to reduce vulnerability to infrequent (extreme) events, the project can be evaluated only if the foreseen event occurs before evaluation of the project. If such an event does not occur, it may be difficult to determine if the project was properly implemented. Furthermore, climate variation is not the only long-term factor that should be taken into account as changes for example in socio-economic conditions, which affect adaptive capacity and the overall vulnerability level, are also relevant to the evaluation of adaption projects.