Structure of the work

The PROTECT work plan adopts a work package structure that is specifically designed to address the challenges posed in the project call. WP-1 and WP-8 are overarching work packages, dedicated to project management and coordination of communication, dissemination and exploitation activities, respectively. The scientific core of PROTECT consists of six tightly linked WPs that address specific scientific questions. A key feature of the project design is a ‘twin-track’ approach (Figure 1). A ‘Fast-Track’ will use existing Antarctic, Greenland and glacier SLR estimates to provide an initial iteration of the stakeholder co-design of project methodology (WP-2) and the generation of SLR projections meeting specific stakeholder needs (WP-7). In parallel, four work packages (WP-3 to 6) will 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 work packages.

Figure 1: PROTECT work plan summary and relation between work packages. WP-2 co-designs and co-produces sea level projections and coastal climate services together with users and stakeholders, based on their needs. WP-3 improves understanding and modelling of critical ice sheet processes to improve SLR contributions from Antarctica (WP-4), Greenland (WP-5) and glaciers (WP-6). WP-7 converts global sea-level changes from melting of the continental cryosphere to regional and local sea-level projections and interprets these in terms of coastal impacts and adaptation needs. These are fed back to WP-2. This procedure will be iterated twice: the first time at an early stage of the project, to select the most appropriate modelling and uncertainty frameworks (Fast-Track, M1-M14), the second to refine the results with the new knowledge being produced during PROTECT (Full-Track, M15-M48). 

WP-2 (Co-design and co-production of sea level projections and coastal climate services) bridges the gap between the sea level projections provided by the scientific community and actual user needs. The latter depend strongly on the value of exposed assets, the desired level of risk aversion and the objectives of various stakeholders such as national governments, regional/local authorities, coastal conservation agencies and insurance/investment companies [Nicholls et al., 2014; Hinkel et al., 2019]. This WP will interact through dedicated workshops with global and local stakeholders, appropriately scheduled to allow an efficient early co-design and co-production of the products (Fast-Track) before full integration of PROTECT results within the produced SLR projections (Full-Track). WP-2 includes representative applications on targeted case studies that address vulnerable coastal ecosystems, communities and infrastructures in Europe (France and the Netherlands), Greenland and the Maldives.

WP-3 (Process understanding and model improvement) addresses physical processes that play a key role in the uncertainties surrounding rapidly accelerating ice-sheet mass loss and high-end SLR scenarios [e.g. Ritz et al., 2015, DeConto and Pollard, 2016]. These processes (e.g. ice shelf hydrofracturing, marine ice sheet instability, marine ice cliff instability, subglacial processes) all represent nonlinear interactions of the ice sheet surface and base with the atmosphere and ocean, and have the potential to strongly affect future ice sheet evolution. This WP will push forward our basic understanding of these interactions, to inform the other WPs on how to improve state-of-the-art modelling of ice sheets, and prepare the next generation of coupled atmosphere/ocean/ice sheet models.

WP-4 (Contribution of the Antarctic Ice Sheet to SLR)focuses on the AIS as a potential game-changer for future SLR. Through various instabilities and feedbacks, the AIS has a poorly-constrained potential for a multiple-metre contribution to SLR in the coming centuries [IPCC, 2013; DeConto and Pollard, 2016]. This WP uses the results of WP-3 in stand-alone ice sheet models as well as fully coupled ice sheet/ocean model systems to assess the sea-level commitment and reversibility of ice loss from the AIS on decadal (until 2050), centennial (until 2100) to millennial (beyond 2500) time scales. Specific attention will be given to the vulnerable Amundsen Sea sector, where ice shelf thinning through basal melt by the relatively warm ocean and the potential for marine ice sheet instability currently causes the largest mass loss from the AIS. The contemporary changes in this relatively densely observed region will better constrain the PROTECT ice sheet models before exploring the future evolution of the AIS.

WP-5 (Contribution of the Greenland Ice Sheet to SLR) addresses contemporary and future mass losses of the GrIS as a major source of SLR. The Arctic is experiencing the fastest cryospheric changes on Earth, as exemplified by the rapid retreat and thinning of its sea ice cover, the thawing of permafrost, the melting of glaciers (e.g. Alaska, Canadian Arctic) and mass loss of the GrIS. The latter is currently the largest single source of SLR, with mass losses steadily increasing over the last two decades but with very large interannual variability. Using stand-alone and coupled ice sheet/atmosphere/ocean models, this WP will assess the relative roles of natural vs. anthropogenic forcing of recent GrIS mass loss, so as to provide better constrained projections of its evolution on the time scales of interest (2050, 2100, 2500).

WP-6 (Contribution of glaciers to SLR) will improve estimates of the current and future rate of melting of glaciers. Their melting since the Little Ice Age (LIA) constitutes the largest cryospheric contribution to 20th century SLR and is expected to remain highly significant in the present century. Owing to their large number (estimated >200,000), specialized models and methods have been designed to hindcast and predict their evolution. By combining emerging EO and modelling techniques, this WP will introduce a new class of models that quantifies and predicts global glacier mass balance at the scale of individual glaciers, rather than grouped regionally as was common practice thus far. 

WP-7 (Regional sea-level change and implications) combines the results of WP-4, 5 and 6 and other sources of SLR (e.g. thermal expansion and changes in terrestrial water storage) into a sea-level model to produce mutually consistent scenarios (2050, 2100, 2500) of regional and local SLR. SLR is far from homogeneous over the globe, as it represents multiple processes acting at various space and time scales. In addition, WP-7 assesses coastal impacts and adaptation needs at the regional and global scale. The outcome of WP-7 will feed back into WP-2 to co-produce sea-level projections and climate services with stakeholders, using both the Fast-Track and Full-Track approaches (see Figure 1.2). The first feedback is planned in an early stage of the project, to design and test the most appropriate modelling and uncertainty frameworks (Fast-Track, M1-M14). The second feedback will refine these initial results with the new scientific knowledge produced during PROTECT (Full-Track, M15-M48).

To reach its objectives, PROTECT deploys a range of expertise and methodologies: (i) a transdisciplinary approach for co-design and co-construction of SLR scenarios, (ii) satellite Earth Observation of polar and mountainous regions, (iii) stand-alone and coupled numerical models of atmosphere, ocean, ice sheets and glaciers, and (iv) improved numerical and statistical approaches to compute probability distributions of sea-level changes and assess coastal impacts.