The overarching scientific objective of PROTECT was to assess and project changes in the land-based cryosphere with quantified uncertainties to produce robust global, regional, and local projections of sea-level rise across diverse timescales. A distinctive feature of the project was strong collaboration between coastal planning stakeholders and sea-level scientists (from glaciologists to coastal impact specialists), aimed at identifying key risks and opportunities from global to local scales, boosting European competitiveness in climate services, and supporting coastal adaptation and mitigation planning.
PROTECT aimed to: (a) assess the current mass balance of ice sheets and glaciers, quantify the roles of anthropogenic forcing and internal climate variability in their changes, and use remote-sensing observations to evaluate and improve projection models; (b) apply improved understanding of short-term variability to make projections to 2050, relevant to today’s coastal management; (c) use newly developed, coupled climate–ice sheet models to project sea-level rise from glacier and ice sheet changes to 2150, aligned with IPCC planning horizons; and (d) assess the irreversibility of mass loss and associated sea-level rise commitment through 2300 and beyond, critical to the viability of coastal cities, small islands, and low-lying states.
PROTECT adopted a ‘twin-track’ approach. The ‘Fast-Track’ used existing Antarctic, Greenland, and glacier SLR estimates to initiate stakeholder co-design of methodology (WP2) and generate early projections tailored to stakeholder needs (WP7). In parallel, four research packages (WPs 3–6) addressed critical scientific questions related to land-ice mass loss affecting global SLR estimates. These advances informed the ‘Full-Track’, which used the same co-designed methodology but with updated SLR estimates from new scientific developments.
PROTECT advanced the state of the art in several key areas of sea-level science. The project introduced improved representations of cryospheric processes—ice shelf damage, calving, firn evolution, and sub-shelf melting—within ice-sheet models, integrating them into ensemble frameworks. It also enabled coupled interactions between atmosphere, ocean, and ice sheets, with model couplings and parameterisations adapted to European systems. These innovations improved the realism and relevance of projections by quantifying uncertainties out to 2300. Crucially, PROTECT complemented technical progress with strong stakeholder engagement and policy-relevant outputs, ensuring science directly supported coastal adaptation and placing PROTECT at the forefront of probabilistic, stakeholder-oriented SLR research. This was reinforced by policy briefs, an open-access SLR webtool, educational resources and games, and a public-facing art exhibition—all designed to enhance awareness, usability, and impact. Societal outcomes include improved public understanding of sea-level risks, better-informed decision frameworks, and stronger paths toward sustainable coastal resilience.
