Exploring the limits and gaps of flood adaptation

Flood adaptation measures such as levees, food-proofng structures, nature-based solutions and food insurance are essential to cope with the growing food risk caused by climate change and urban development into food-prone areas. However, many communities in food zones are ill-protected because the implementation of adaptation measures is hindered by a variety of constraints to adaptation, including the cost, limitations on institutional capacity and societal inertia. When adaptation eforts fall short relative to a desired level due to a combination of constraints, it results in an ‘adaptation gap’. Here we present a risk-based framework to systematically examine the technical, social and behavioural constraints that contribute to adaptation gaps. We argue that, without overcoming these constraints, adaptation gaps will widen under climate change, exposing increasing populations to heightened food risk. This may then require more radical actions including relocation, as risks become intolerable. We argue that quantitative food risk assessments must consider constraints and adaptation gaps systematically, especially where they may lead to food adaptation limits. Without assessing these dynamic relationships, food managers may overestimate the efcacy of food adaptation measures and underestimate the unequal distribution of food risks.