Periodic Reporting for period 2 - PROTECT (PROjecTing sEa-level rise : from iCe sheets to local implicaTions)
Reporting period: 2022-03-01 to 2023-08-31
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 (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 to: (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 SLR 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 2300 and beyond, the timescale relevant to the long-term viability of coastal cities, small islands and low-lying states.
PROTECT adopts 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 (WP2) and the generation of SLR projections meeting specific stakeholder needs (WP7). In parallel, four work packages (WPs 3, 4, 5, 6) address critical science questions related to the land-ice mass loss affecting estimates of global SLR. This will then enable the ‘Full-Track’ to be completed, which will repeat the methodological advances of the Fast-Track but using the SLR estimates arising from the four research WPs.
PROTECT aims to: (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 SLR 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 2300 and beyond, the timescale relevant to the long-term viability of coastal cities, small islands and low-lying states.
PROTECT adopts 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 (WP2) and the generation of SLR projections meeting specific stakeholder needs (WP7). In parallel, four work packages (WPs 3, 4, 5, 6) address critical science questions related to the land-ice mass loss affecting estimates of global SLR. This will then enable the ‘Full-Track’ to be completed, which will repeat the methodological advances of the Fast-Track but using the SLR estimates arising from the four research WPs.
Significant progresses towards our objectives have been made:
1 - Significantly improving our understanding and model representation of ice-sheet processes
This objective is primarily supported by WP3, which aims to study the main processes affecting the mass balance of the polar ice sheets to provide recommendations for conducting the ensemble of simulations that will feed our SLR projections. Reports have been made on MICI (Marine Ice Cliff Instability), calving, friction laws and sub-shelf melting parameterizations as well as reports on improved representation of contemporary Greenland and Antarctic firn layers through better modelling of firn processes and surface climate and mass balance. This work continued during RP2 by reviewing and proposing new sub-shelf melt parametrizations for stand-alone ice sheet models (PROTECT paper #49) and improving the prediction of transient Greenland and Antarctic firn layers (#63). EO activities, in addition to establishing polar ice sheet mass balances, provide information on processes within the firn and contribute to improving the physics and callibration of our models. The first model intercomparison exercise dedicated to iceberg calving has been launched and the results from the wider international community are starting to arrive and be analysed. Continuing to improve the representation of processes in polar ice sheet models will be pursued, through the scientific publication of the results obtained, the implementation in the NEMO ocean model of sub-ice-shelf ocean boundary layer parameterisation, the continuation of the calvingMIP intercomparison exercise.
2 - Providing a step change in modelling the interactions and feedbacks between atmosphere, ocean, and ice sheets
The forcing of the ocean and atmosphere on the polar ice sheets is at the origin of their current mass loss and contribution to SLR. Improving the representation of interactions and feedbacks is a priority for the international community and PROTECT (development of new parameterisations of basal melting under ice shelves for stand-alone ice sheet models (#49)), the influence of the atmosphere on the ice sheet has been at the heart of our efforts (development of the CISSEMBEL model protocol to provide a model for both fast downscaling and coupling atmosphere and ice).
3 - Improving the robustness of SLR projections, with a propagation of uncertainties from global to regional scales
We are developing state-of-the-art emulation techniques to describe multi-model, multi-perturbed parameter ensembles of land ice projections for individual ice sheet basins and glacier regions, which propagate as many uncertainties as feasible from global SLR to regional SLR projections and allow sensitivity analyses for low/high-end projections. Calibration of the simulations with observations are also part of our methodology, already employed and showing an improved robustness of the projections (#71). The methodological bases started to be published (#61), and are progressively incorporated into the FACTS sea level framework, to allow use by other studies and IPCC assessments. The necessary ingredients for this emulation have been gradually put in place, from surface mass balance projections for both Antarctica and Greenland, the projection of the evolution of the Greenland ice sheet, the development and application of a calibration-validation framework for glaciers, the uncertainty assessment of debris cover parametrisations in glacier models, and the long-term projections of the Antarctic ice sheet to SLR until 2500 and beyond. Efforts must continue, particularly with the multi-model projections of glaciers and the Antarctic ice sheet up to 2150. The work in progress is already featured in high-impact journals (#36, #43, #53, #55).
4 - Assessing the societal implications of high-end ice-sheet SLR over decades to centuries
Innovative methodological foundations have been put in place, and a first policy brief raising the need to anticipate adaptation to 2 m SLR has been issued. We have contributed to the publication of important results in high-impact journals (#58, #67) and the projections currently being made will be fully exploited by the end of the project.
5 - Developing and mentoring the next generation of sea-level scientists
Two ECSs representatives take part to the scientific steering committee, events are organised by and for ECSs, in particular by enabling senior researchers to enlighten ECSs on their career path. The career development of the ECSs who have contributed to PROTECT is encouraged and monitored. Those efforts will be pursued until the end of PROTECT.
1 - Significantly improving our understanding and model representation of ice-sheet processes
This objective is primarily supported by WP3, which aims to study the main processes affecting the mass balance of the polar ice sheets to provide recommendations for conducting the ensemble of simulations that will feed our SLR projections. Reports have been made on MICI (Marine Ice Cliff Instability), calving, friction laws and sub-shelf melting parameterizations as well as reports on improved representation of contemporary Greenland and Antarctic firn layers through better modelling of firn processes and surface climate and mass balance. This work continued during RP2 by reviewing and proposing new sub-shelf melt parametrizations for stand-alone ice sheet models (PROTECT paper #49) and improving the prediction of transient Greenland and Antarctic firn layers (#63). EO activities, in addition to establishing polar ice sheet mass balances, provide information on processes within the firn and contribute to improving the physics and callibration of our models. The first model intercomparison exercise dedicated to iceberg calving has been launched and the results from the wider international community are starting to arrive and be analysed. Continuing to improve the representation of processes in polar ice sheet models will be pursued, through the scientific publication of the results obtained, the implementation in the NEMO ocean model of sub-ice-shelf ocean boundary layer parameterisation, the continuation of the calvingMIP intercomparison exercise.
2 - Providing a step change in modelling the interactions and feedbacks between atmosphere, ocean, and ice sheets
The forcing of the ocean and atmosphere on the polar ice sheets is at the origin of their current mass loss and contribution to SLR. Improving the representation of interactions and feedbacks is a priority for the international community and PROTECT (development of new parameterisations of basal melting under ice shelves for stand-alone ice sheet models (#49)), the influence of the atmosphere on the ice sheet has been at the heart of our efforts (development of the CISSEMBEL model protocol to provide a model for both fast downscaling and coupling atmosphere and ice).
3 - Improving the robustness of SLR projections, with a propagation of uncertainties from global to regional scales
We are developing state-of-the-art emulation techniques to describe multi-model, multi-perturbed parameter ensembles of land ice projections for individual ice sheet basins and glacier regions, which propagate as many uncertainties as feasible from global SLR to regional SLR projections and allow sensitivity analyses for low/high-end projections. Calibration of the simulations with observations are also part of our methodology, already employed and showing an improved robustness of the projections (#71). The methodological bases started to be published (#61), and are progressively incorporated into the FACTS sea level framework, to allow use by other studies and IPCC assessments. The necessary ingredients for this emulation have been gradually put in place, from surface mass balance projections for both Antarctica and Greenland, the projection of the evolution of the Greenland ice sheet, the development and application of a calibration-validation framework for glaciers, the uncertainty assessment of debris cover parametrisations in glacier models, and the long-term projections of the Antarctic ice sheet to SLR until 2500 and beyond. Efforts must continue, particularly with the multi-model projections of glaciers and the Antarctic ice sheet up to 2150. The work in progress is already featured in high-impact journals (#36, #43, #53, #55).
4 - Assessing the societal implications of high-end ice-sheet SLR over decades to centuries
Innovative methodological foundations have been put in place, and a first policy brief raising the need to anticipate adaptation to 2 m SLR has been issued. We have contributed to the publication of important results in high-impact journals (#58, #67) and the projections currently being made will be fully exploited by the end of the project.
5 - Developing and mentoring the next generation of sea-level scientists
Two ECSs representatives take part to the scientific steering committee, events are organised by and for ECSs, in particular by enabling senior researchers to enlighten ECSs on their career path. The career development of the ECSs who have contributed to PROTECT is encouraged and monitored. Those efforts will be pursued until the end of PROTECT.
The Fast-Track process has been completed and we entered the Full-Track, which is built 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 SLR projections in line with the needs of sea-level practitioners, PROTECT has paved the way to support EU and global policy decisions in terms of sustainable development of coastal zones. As an illustration, a policy-Brief raising the need to anticipate adaptation to 2 m sea-level rise has been issued (see #73).