Agreed metrics

Mckay et al (2010) have differentiated between natural, constructed and proxy metrics. Natural metrics directly measure directly an objective and represent the common unit of measure of a given variable. Constructed metrics are developed to directly measure an objective when no natural metric exists. Proxy metrics are used to indirectly measure a given variable because of the relative ease of measurement and availability. Unlike in climate change mitigation, where carbon dioxide equivalence can be used as a common metric, adaptation lacks an agreed metric to determine whether the project objectives, which may be multiple, have been met. Stadelmann et al (2011) have attempted to condense the multiplicity of objectives and outcomes that characterise adaptation projects into two metrics: Saved Wealth and Save Health. Although this option may look appealing as the metrics identify centre on impact, they do not capture the diversity of objectives and outcomes of adaptation projects. Watkiss and Hunt (2011) have suggested the elaboration of a list of common metrics to measure the impact of adaptation measures, depending on the sector but standardized in order to make different interventions comparable. The proposed metrics are however very general and may not be suitable to the wide range of adaptation interventions. The lack of a single adaptation metric is ultimately connected to the choice of possible vulnerability indicators (e.g. qualitative, quantitative, sectoral, and binary) and how different indicators’ typologies can meaningfully coexist and be used to assess different projects.
To conclude, it should be noted that adaptation projects invariably include trade-offs and synergies with general sustainable development objectives, and priority should be given to no-regrets and low-regrets measures, preventing mal-adaptation and accounting for the environmental and social impact of the adaptation measures themselves. This calls for integrated assessments and evaluation frameworks that are able to encompass the multiple dimensions of adaptation projects and adequately analyse them (GEF 2008).