Peter Alexander

My work focuses on the social, economic and ecological interactions within the food and land use systems, typically applying data and computationally intensive techniques, such as agent-based modelling.  The work considers interactions between climate change adaptation and mitigation, as well as how the globalisation of the food system creates teleconnections between actions in one location having consequences in others.  A particular interest is how shocks—ranging from climate extremes and market or input-price volatility to policy disruption and geopolitical instability—propagate through international trade, shaping vulnerabilities and displacing environmental pressures across regions. How land use and food system changes interact with dietary choices and human health, e.g. patterns of food consumption influencing environmental outcomes and environmental changes impacting nutrition and health, are also considered in my research. My research also quantifies how these food-system changes affect biodiversity and ecosystem functioning, including through habitat change and trade-driven displacement of impacts.

I am a Lead Author for the IPBES Spatial Planning and Ecological Connectivity Assessment, which began in 2025 and is due to be published in 2027. I was a Lead Author for the 2022 IPCC (WGII) report assessing the Impacts, Adaptation and Vulnerability to climate change, and am now a coordinating lead author (CLA) on UNEP’s 7th Global Environmental Outlook (GEO-7) for the Food System Transformation Pathways chapter. I'm also a member of World Climate Research Programme (WCRP) Safe Landing Pathways working group, and Defra’s ELM Climate Change Expert Panel.

Changes in climate (including increasing variability and extremes), population growth, and socio-economic conditions mean that the global land use system will need to adapt to provide the world with food, timber, and other resources. The extent and location of agriculture and forestry will shift, farmers will change the kinds of crops they grow, and new fertiliser and irrigation patterns will emerge. These land use changes may conflict with plans to achieve carbon sequestration in terrestrial ecosystems as a climate change mitigation measure, and are likely to further increase pressure on biodiversity.

To better understand this web of interconnections I have been leading, in collaboration with others, the development of the Land System Modular Model (LandSyMM).  This includes more detailed yield data and responses to intensity of production (e.g. fertiliser and irrigation use) and a greater spatial specificity than previously possible in other approaches, as well as representing change dynamics in food demand and international trade.  This model has already been used to quantify the impacts of alternative future pathways on ecosystem service indicators such as the land carbon balance, runoff, and nitrogen pollution, and explore the impact of future changes in diet on habitat availability in biodiversity hotspots, as well as the reverse—looking at the food security implications of different land conservation scenarios.

Google Scholar

Land Use Lab research group