Measuring climate change adaptation policy output: Toward a two‐dimensional approach

As jurisdictions across the globe step up their efforts to adapt to climate change, it is important to assess progress by taking stock of and comparing adaptation policy. However, scholars and practitioners are struggling to conceptualize and measure adaptation policy. In this article, we propose a new two-dimensional framework to measure public adaptation policy output, namely, the Climate Adaptation Policy Index (CAPI). The index combines multiple indicators from two core interdependent dimensions, namely, an institutionalization dimension focusing on strategic plans and administrative capacities for adaptation; and a measures dimension capturing concrete adaptation measures in relevant action areas such as in green and open spaces, transport infrastructure, buildings, public education, and disaster management. Our approach is extensive but feasible and may be adjusted for use in different contexts and policy areas. We probe our approach at the local level using original survey data from a diverse sample of 211 municipalities located in the state of Hessen in central Germany. A factor analysis suggests that the two dimensions constitute a meaningful measurement of municipal adaptation policy output. A cluster analysis identifies five groups of municipalities representing different stages of adaptation policy progress in Hessen. Finally, a regression analysis examines potential determinants of local adaptation policy making such as the size and wealth of municipalities. The results highlight the potential of the CAPI for analyzing both the state and the making of municipal adaptation policy.