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Globally, the rapid retreat of coastal cliffs poses a profound risk to property, transport infrastructure, and public safety. To quantify and compare cliff top and cliff face retreat and identify erosion processes, this study combines historical (1842–2000) maps and orthophotos with contemporary UAV surveys (2019–2023) to quantify cliff top and cliff face retreat along a 240 m wide coastal drumlin in Galway Bay, Ireland. Retreat rates for the cliff top and cliff face were calculated using 2D mapping and 3D modelling, respectively. Critically, the choice of method has a significant impact on calculated rates of cliff top retreat, with output from the 2D mapping approach (0.14 +/− 0.02 m yr−1) being double that of the 3D modelling approach (0.08 +/− 0.02 m year−1). The aperiodic development of a talus cone, which temporarily protects the cliff from storm waves, also influences estimates of cliff retreat. The repeat cycles of talus slope formation and removal in this high wave energy environment suggest that the drumlin scarp transitions between a periodically transport-limited and supply-limited system over short- and long-time periods, respectively, on the continuum of cliff types. These results warrant further research to identify and quantify the rates, patterns, drivers (marine and subaerial processes), and timing of cliff retreat in response to climate change. [ABSTRACT FROM AUTHOR]

One area where climate adaptation policies are proving difficult to design and implement is at the coast. On one hand, some of the most severe impacts of climate change are being recorded at the coast – especially through erosion and flooding – whilst on the other hand, these areas represent complex land-sea planning and policy interfaces. This paper analyses the coherency of policies along Ireland's coast from a climate adaptation perspective. Results suggest that many policies are developed in an ad-hoc fashion around the needs of single sectors. Improved policy coherence at all levels of governance is required to address this. [ABSTRACT FROM AUTHOR]