Reframing strategic, managed retreat for transformative climate adaptation.

Human societies will transform to address climate change and other stressors. How they choose to transform will depend on what societal values they prioritize. Managed retreat can play a powerful role in expanding the range of possible futures that transformation could achieve and in articulating the values that shape those futures. Consideration of retreat raises tensions about what losses are unacceptable and what aspects of societies are maintained, purposefully altered, or allowed to change unaided. Here we integrate research on retreat, transformational adaptation, climate damages and losses, and design and decision support to chart a roadmap for strategic, managed retreat. At its core, this roadmap requires a fundamental reconceptualization of what it means for retreat to be strategic and managed. The questions raised are relevant to adaptation science and societies far beyond the remit of retreat.