Transformational adaptation (TA) to climate risks has gained broad interest. While existing case studies and frameworks discuss key dimensions and elements that constitute TA to distinguish it from ‘business as usual’ or ‘incremental’ adaptation, a universally accepted definition of the concept remains elusive. Here we used a three-round Delphi study with experts from across the globe, to ascertain the level of agreement on key elements of TA, and to assess differences across expert types, geographical focus and administrative levels. We find broad agreement on 13 elements that are important in a definition of TA: root causes, climate resilience, time-horizon, diversity of knowledge, depth of change, distributive justice, context specificity, multiscale, restructuring, persistence, maladaptation, avoiding lock-ins and systemic change. However, notable differences exist in what expert subgroups value as important elements. Clarifying what TA entails is crucial for developing effective policies and strategies, ensuring meaningful progress in addressing climate change.
Biesbroek et al. (2026) studied this question.