European land use and land cover futures: a global computable general equilibrium assessment with sub-national detail and a climate application

Abstract

Land constitutes a fundamental foundation for human life and well-being. Beyond providing agricultural land, habitats, and spaces for retreat and recreation, it plays a crucial role in sustaining biodiversity and functioning ecosystems, and it is a key component of the climate system. Today, humanity already uses more than 70% of the global ice-free land surface, making land use and land cover one of the most significant anthropogenic influences on the Earth system. <br/> While humanity has long benefited from changes in land use and land cover, these are now increasingly associated with significant environmental pressures, including land degradation, nutrient run-off, biodiversity loss, and the release of greenhouse gas emissions. In the context of growing land demand and increasingly globalised supply chains, a key challenge for society is therefore to manage land in a way that simultaneously meets social, economic, and environmental objectives. <br/> To address uncertainties in future land use and land cover developments, land and climate research examines various socio-economic development scenarios. Within these scenarios, key drivers of land use and land cover change are quantified based on consistent, predefined narratives. This enables a systematic analysis of potential future developments and their socio-economic and environmental impacts. <br/> The main contribution of this dissertation lies in the development of a new methodological approach for generating land use and land cover scenarios. This approach is based on the computable general equilibrium modelling platform CGEBox and quantifies the five so-called Shared Socio-Economic Pathways up to 2050. Compared to existing approaches, it improves both the transparency and the flexibility of scenario development. Furthermore, the new quantifications combine global economic consistency with a high level of regional and sectoral detail and enhance the representation of socio-economic processes. <br/> As part of this work, the new land use and land cover projections are further used in a climate application to analyse land-atmosphere feedbacks resulting from land cover changes. By integrating socio-economic modelling, spatial downscaling, and physically consistent regional climate simulations, a new conceptual framework enables a coherent analysis of these effects across different scales. <br/> Overall, this dissertation contributes to an improved understanding of how socio-economic uncertainties translate into regional land use and land cover dynamics and associated climate impacts. These insights support economically grounded land use and land cover planning, as well as the design and assessment of land-based adaptation and mitigation measures, and policy-relevant decision-making.