Global land use dynamics in agriculture and forestry under socioeconomic and climate change scenarios

As global demand for natural resources continues to grow, the land system is experiencing increasing pressure to provide food, materials, and energy. Achieving sustainable land management is a common goal for landowners and policymakers to ensure we can meet society's present and future needs. Given the uncertainties surrounding the world's socioeconomic and climate trajectory, it is essential to consider a variety of potential scenarios for how the land system might develop. Existing research on future land use change suffers from a lack of diversity in the models and scenarios explored, leading to gaps in our understanding of the impacts of land use policies. This thesis examines global land use dynamics, focusing on how long-term changes in demand for agricultural and forestry products will impact global land use patterns. It addresses existing research gaps by providing novel, spatially detailed global land use change scenarios using the Land System Modular Model (LandSyMM). This global land use modelling framework simulates the demand for agricultural and forestry commodities, land use change, and international trade, using realistic, biophysically derived crop and forest yield responses. The first part of this research investigates the response of global forest management to changes in wood demand. Forests are a prominent component of the Earth’s land cover and are valued for their diverse ecosystem services. Global demand for wood is projected to increase in all scenarios explored here, driven by population and economic growth. Results reveal that forest management will likely intensify in the following decades in most wood-producing regions, thus putting additional pressure on forest ecosystems. Reducing the impact of human land use on natural ecosystems is an integral part of policies aimed at mitigating climate change and preserving biodiversity. Subsequently, the thesis assesses the potential to reduce the global agricultural land footprint by comparing the land use requirements of bioenergy, photovoltaics, and agrivoltaics. Results show that substituting energy crops for photovoltaic panels reduces cropland expansion, fertiliser use, and irrigation water withdrawal. By combining solar energy generation with crop production (agrivoltaics), a higher land use efficiency is achieved, leading to further reductions in cropland expansion and loss of natural land cover. In all scenarios explored here, land use outcomes are strongly influenced by international trade, which is increasingly important in shaping global land use patterns. Using the United Kingdom as a case study, the final research chapter of this thesis investigates the importance of trade for global land use patterns by quantifying the global land footprint of the UK’s food and feed imports. Results reveal the global interconnectedness of the food and land system, thus highlighting the environmental consequences for exporting countries. This thesis illustrates some of the key factors that shape global land use in the context of changing demand for natural resources.