Adaptation Pathways Planner 2D: Sea-Level Rise & Tipping Points

Coastal climate adaptation is rarely a single fixed design — it is a sequence of strategies switched over decades as the hazard outgrows each one's capacity. This 2D chart implements the same Dynamic Adaptive Policy Pathways (DAPP) model as the 3D version: a sea-level-rise hazard curve H(t) = R·t + A·t² climbs against your currently chosen defense's design capacity, and when it crosses that ceiling — an Adaptation Tipping Point — you must switch to the next pathway (Seawall → Beach Nourishment & Dunes → Hybrid Green-Gray Infrastructure → Managed Retreat), each higher-capacity but costlier to adopt. Drag the chart to pan through time and scroll to zoom; a lane-ladder strip below shows every pathway's headroom at a glance.