Participatory workshops will be undertaken with a range of land use and food system stakeholders, including farmers, retailers, water companies, local planning representatives, and policy makers to develop a consensus derived systems map of NbS in the UK. Following the initial workshop, the systems map will be shared with national stakeholders from other regions to evaluate its representativeness. From there, the systems map will be used to generate the underlying model architecture, e.g. the stocks and slows of the system dynamics.

A singular System Dynamics (SD) model will be designed with five sub-systems; A – Land-Use decision making, B – Trade (macro-economics), C – Supply chains (regional economics), D – Policy, and E – Climate scenarios. Sub-model A on Land-use decision making will be run in CRAFTY GB, whilst sub-models B, C, and D will be designed as SD sub-units. All four sub-models will use parameter estimates from new survey data and literature values. Sub-model E will be run on the Met Office JULES land surface model, which will generate spatially explicit maps, resolved at 1km, of climate impacts on terrestrial systems, which can be used as inputs into the SD model. Different parameter combinations within these sub-models will allow us to test the barriers to and enablers of NbS in multifunctional landscapes and to assess the resilience of NbS under different warming scenarios.

The first critical step in the SD modelling process is to evaluate the systems structure. Using Approximate Bayesian Computation allows us to define posterior distributions for free model parameters (those that are challenging to quantify) and compare subsequent model outputs against historical records. Evaluating goodness of fit with historical trends will allow testing of hypotheses regarding the drivers of NbS uptake and impacts developed through WPs 1, 2 and 3.

Step 2 will contrast system sensitivities for different NbS options providing insight into the actions needed to scale up NbS as well as the impacts of different uptake rates on carbon sequestration, biodiversity net gain, land use, and food security.

Step 3 will test the resilience of NbS under different warming scenarios to 2050, including a business-as-usual scenario. Integrating model outputs from the Met Office JULES Global Land 7.0 configurations, we will test the long-term impacts of NbS within multifunctional landscapes, particularly in response to drought and flood risks. The results of step 3 will feed into WP4 and WP5 to demonstrate the potential of NbS in delivering resilient multifunctional landscapes, and in communicating the measures required to scale up NbS in regional climate adaptation plans, as well as the implications of NbS uptake on the UK food system.

Other deliverables include open-source code, a front-facing app to run the model off server, academic publication, awebinars for academic and policy audiences on model findings.