MOBIliser la DYnamique des stocks de Carbone dans les sols et la biomasse DYnamiC : intégrer les héritages du passé dans les solutions futures fondées sur la nature – MOBIDYC

Terrestrial ecosystems are increasingly called upon to meet the dual challenge of mitigating climate change by sequestering carbon (C), while supplying multiple renewable materials in a bio-economy. Because of the relative inertia of C pools in soils and biomass, the success or failure of meeting these challenges through Nature-Based Solutions (NBS) depends not only on future land-use and climatic conditions, but also on the legacy effects from past land-use. However, legacy effects remain largely overlooked, due to the lack of large-scale reliable, systemic modelling approaches, tightly integrating the long-term interactions between soil and biomass C dynamics and their multiple drivers.

MOBIDYC tackles these research-gaps through an innovative modelling approach to answer the following question: How will past land-use trajectories affect the potential impact of future NBS?

To answer this question, MOBIDYC will first calibrate and validate diachronically an accurate model of soil and biomass C dynamics at the territorial resolution, i.e., the level of NUTS 2 regions, in the European Union from 1961 to 2020. This pioneering work will be possible thanks to the new game-changing Land-Use and Coverage Area Survey released in 2022. Second, MOBIDYC will seek to quantify and understand the interrelations between shifts in soil and biomass use, and their immediate and time-lag legacy effects on the terrestrial C dynamic. To that end, MOBIDYC will create an innovating biogeochemical modelling framework to link provisioning and regulating ecosystem services, in connection to broader shifts in societal resource uses. Building on steps 1 and 2, MOBIDYC’s step 3 will explore the option space of NBS by 2050, including the levers of bioenergy use, forest recovery, diet, trade and agricultural practices, and quantifies their impacts to meet sustainability challenges. Overall, MOBIDYC will provide massive empirical and methodological advances to better weigh different NBS.