Uncertainty and shifting baselines
The uncertainty surrounding climate change impacts, including the
frequency and intensity of extreme events and the long-term
repercussions of climate change effects, has to be considered when
designing evaluation frameworks for adaptation projects. Adaptation
takes place against a backdrop of evolving climate hazards, which may
become more frequent and severe, resulting in climate-related losses, or
become less pronounced over the timescale of a project. The impacts of
adaptation projects must be assessed against changing hazard profiles,
meaning that it is not necessarily sufficient to compare losses or
damages before and after adaptation interventions. Where trends in
climate hazards occur over periods during which assessment of project
impacts are taking place, indicators of loss or damage must be
‘normalized’ to account for changing hazards. Evaluation methodologies
based on the before-after approach assume stability in the underlying
conditions of the baseline. However, in relation to adaption project
implemented against the backdrop of changing climatic conditions, the
baseline shifts in uncertain and emerging ways and the validity of the
comparison of the post-intervention effect to the pre-intervention
baseline does not present a clear indication of the effect of the
adaptation project.