Periodic Reporting for period 1 - PROTECT (PROjecTing sEa-level rise : from iCe sheets to local implicaTions) Reporting period: 2020-09-01 to 2022-02-28 Summary of the context and overall objectives of the project The overarching scientific objective of PROTECT is 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 on a wide range of timescales. One of the specificities of the project is the strong collaboration between coastal planning stakeholders and sea-level scientists (ranging from glaciologists to coastal impact specialists) to identify relevant risks and opportunities from global to local scales and enhance European competitiveness in the provision of climate services and support coastal adaptation planning and mitigation measures.PROTECT aims at reaching the following overall goals: (a) assess the contemporary mass balance of ice sheets and glaciers, quantify the relative importance of anthropogenic forcing and internal climate variability to ice sheet and glacier changes, and use remote-sensing observations to evaluate and improve the models used for ice sheet and glacier projects; (b) use the improved understanding of short-term variability in glacier and ice-sheet mass balance to make projections until 2050, the time scale of relevance to many of today’s coastal management decision; (c) use a range of newly-developed, coupled climate-ice sheet models to project sea-level rise as a result of glacier and ice sheet mass change until 2100, the IPCC timescale that is relevant for long-term infrastructure planning; (d) assess the irreversibility of glacier and ice-sheet mass loss and the associated sea-level rise commitment to 2500 and beyond, the timescale relevant to the long-term viability of coastal cities, small islands and low-lying states.PROTECT adopts a structure that is designed to address those challenges, based on a ‘twin-track’ approach. A ‘Fast-Track’ uses existing Antarctic, Greenland and glacier SLR estimates to provide an initial iteration of the stakeholder co-design of project methodology (work package 2) and the generation of sea-level rise projections meeting specific stakeholder needs (work package 7). In parallel, four work packages (work packages 3, 4, 5, 6) address critical science questions related to the land-ice mass loss affecting estimates of global sea-level rise. This will then enable the ‘Full-Track’ to be completed, which will repeat the methodological advances of the Fast-Track but using the sea-level rise estimates arising from the four research work packages. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far The project activities over the first reporting period allowed the consortium to complete the Fast-Track process and make significant progress towards our objectives:- Objective 1 ‘Significantly improving our understanding and model representation of ice-sheet processes’ This objective is primarily supported by WP3 which, from the start of the project, has focused on the study of the main processes affecting the mass balance of the polar ice sheets. Recommendations on the modelling approaches to be used preferentially were provided to the whole consortium.- Objective 2 ‘Providing a step change in modelling the interactions and feedbacks between atmosphere, ocean, and ice sheetsThe ocean forcing on polar ice sheets is essential to the observed retreat of Greenland and Antarctica, and PROTECT first activities contributed to improve its representation in numerical models. First, by providing a Python package containing the main existing basal melt parameterisations developed so far and implemented in circum-Antarctic ocean simulations that resolve ice shelf cavities. Recommendations for their use have been made available to the entire consortium. On the basis of this synthesis, the development of new parameterisations is underway for both stand-alone ice sheet models and coupled ocean-ice sheet models.- Objective 3 ‘Improving the robustness of the resulting sea-level rise projections, with a clear propagation of uncertainties from global to regional scales’ Activities associated with the Fast-Track have been completed during the first reporting period, contributing to reach this objective by: (a) interacting with sea-level practitioners and stakeholders to align the relevance of our projections with their needs has been launched through two workshops with stakeholders), (b) Global and regional Fast-Track projections up to 2500 have been delivered, (c) Recommendations for the multi-model experimental design to be used for the upcoming sea-level rise projections has been achieved.- Objective 4 ‘Assessing the societal implications of high-end ice-sheet sea-level rise over decades to centuries’In PROTECT, projections of the land ice contribution to sea level rise will be made by emulating the ice sheet and glacier models. Indeed, uncertainty quantification for computer models using emulation can provide all the generic sea level products identified by PROTECT in co-design with stakeholders: probabilistic predictions and scenarios, high-end and low-end scenarios, learning scenarios. Methodologies to produce global assessments of sea-level rise risks and impacts on decadal to multi-centennial time scales are also being currently developed in WP7. In other words, the Fast-Track allowed us to prepare all the ingredients required to reach this objective and have now to be applied during the Full-Track.- Objective 5 ‘Developing and mentoring the next generation of sea-level scientists’Twenty Early Career Scientists (ECS) are currently hired by PROTECT. Two of them are elected Scientific Steering Committee (SSC) representatives with a yearly mandate, and take part in SSC meetings. Seven meetings have been organised where the ECS discussed with established researchers to learn from their experiences. Other informal meetings are organised within the ECS group on a regular basis to exchange on topics of common interest. Synergies have been developed with other young scientists from PROTECT partners institutions who are welcome to attend the ECS meetings and discussions. At this stage, most of our exploitable results have been made available through peer-reviewed scientific publications. During the first reporting period, 30 articles have been published, 28 are open source. When not open source pre-print of the articles are available online. A comprehensive list of our publications is available on the PROTECT website. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) The activities led during the first reporting period enabled us to complete the Fast-Track process and we are now entering the Full-Track, which will build on the approach taken so far. By developing during the Fast-Track beyond the state of the art methodologies, co-designed with stakeholders, which will allow to establish sea-level rise projections in line with the needs of sea-level practitioners, PROTECT has paved the way to support European Union and global policy decisions in terms of sustainable development of coastal zones. PROTECT logo for publication