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).