Making Robust Decisions in the Face of Uncertainty: Using Climate ModelsTraditionally, adaptation planning has been achieved through so-called ‘top down’ or ‘scenario-led’ methods which focus on developing fine scale climate data from coarse scale Global Climate Models (GCMs). The resulting local-scale scenarios are fed into impact models or mapped against the locations of people or infrastructure assets to determine vulnerability.
Given these uncertainties, the focus should be on identifying and implementing adaptation actions which perform well both under current and possible future climatic conditions. A policy or project should have the effect of improving the ‘adaptive capacity’ or reducing the ‘sensitivity’ of residents and communities – this is the cornerstone of climate resilience. A ‘bottom up’ approach to adaptation planning is an effective way of planning projects in the Caribbean and elsewhere (Wilby and Dessai, 2010; Pielke et al., 2012). The method focuses initially on finding adaptation options which reduce vulnerability to past and present climate variability (as well as ‘non-climatic pressures’). It begins with an assessment of vulnerability to observed climate variability and change. Robust adaptation measures are then identified that would reduce vulnerability under current climate conditions, whilst being acceptable in other terms (e.g. technically, financially, economically, socially, environmentally). Climate models have a major role in decision making. If the lifetime of a project spans several decades, they can be used to establish upper and lower bounds for testing of possible adaptation options. The aim is to identify adaptation options which perform well (though not necessarily optimally) over a wide range of conditions experienced now and potentially in the future- a shift in emphasis from identifying optimal actions to finding robust ones. A further important principle for decision-making in the face of uncertainty is to apply ‘adaptive management’ i.e. a strategy which can evolve and adjust as circumstances change (e.g. Wilby, 2011). Further readingWilby, R. L. and Dessai, S. 2010. Robust adaptation to climate change. Weather, 65(7), pp. 180-185. |