PhD thesis Judith Claassen
'Multi-Hazard Entanglement - Unravelling Historical and Stochastic Multi-Hazard Events’
Natural hazards such as cyclones, floods, droughts, and wildfires often occur in combination, where one event can trigger or intensify another. Traditional risk assessments typically consider these hazards in isolation, which can lead to an underestimation of their overall impact. This thesis addresses the need for a more holistic understanding of multi-hazard events and their interdependencies. It introduces the MYRIAD-Hazard Event Sets Algorithm (MYRIAD-HESA), which combines individual hazard datasets into coherent multi-hazard event sets based on their spatial and temporal overlap. Using this approach, a global database of eleven hazard types was developed for the period 2004–2017, enabling the identification of regional hotspots and common hazard combinations. To better capture statistical dependencies between hazards, the thesis also presents VineCopulas, a Python package for modelling complex relationships between variables such as temperature, wind speed, and precipitation. Building on this, the MYRIAD-Stochastic Vine-copula Model (MYRIAD-SIM) was developed as a stochastic weather generator capable of simulating long-term, spatially coherent weather data. Applications to European case studies demonstrate how this model can estimate the frequency of high-impact multi-hazard events. This thesis contributes to the advancement of multi-hazard risk assessments by offering open-source tools and datasets. These tools, datasets, and findings support researchers and practitioners in making more informed multi-hazard risk management decisions, improving disaster preparedness and resilience.
PhD thesis Hanna Mathilda Dijkstra
‘ Ripples to Waves: How Business Models and Entrepreneurs are Propelling the Transition Towards a Sustainable Plastic System’
Plastic pollution is a growing global challenge, requiring fundamental changes in production, consumption, and waste management systems. This thesis explores how entrepreneurs and innovative business models contribute to the transition towards a more sustainable plastic system. The research shows that a wide range of sustainable business models are emerging, particularly among small enterprises working on plastic and marine pollution. These ventures use diverse strategies to reduce environmental impacts, but face challenges such as unclear market structures, limited support, and gaps in areas like microplastic management. Through interviews and surveys, the thesis identifies different business model types and highlights how entrepreneurs actively shape the systems in which they operate. Those who see their work as contributing to broader system change are more likely to engage in transformative activities. Overall, the findings emphasise that sustainable ventures play a key role in driving systemic change. Strengthening their impact requires innovative revenue models, a focus on higher-value circular strategies, and a broader systems perspective to accelerate the transition towards a sustainable plastic economy.
PhD thesis Thijs Endendijk
‘Homes under Water: From Physical to Financial Flood Risk for Real Estate’
Climate change is increasing flood risks, posing growing threats to the real estate sector through physical damage, business disruption, and financial instability. This thesis examines how flooding impacts real estate from physical to financial dimensions and identifies strategies to improve resilience. Using post-disaster data from the 2021 Dutch floods, the research shows that flood damage mitigation measures - such as barriers and water-resistant construction - can reduce damage by 30–40%, while also revealing that existing damage models may underestimate risk. Beyond direct impacts, flooding causes significant indirect losses, including prolonged business interruption and supply chain disruptions. To assess financial implications, the thesis introduces the Dynamic Integrated Flood Real Estate Impacts (DIFREI) model, linking flood risk to real estate market dynamics. While investors appear relatively resilient, homeowners in high-risk areas may face substantial property devaluation, with potential increases in mortgage risk under worsening climate conditions. The findings highlight the importance of adaptation, improved risk communication, and stronger collaboration between insurers, governments, and financial institutions. Measures such as climate risk labelling, adaptive building standards, and tailored financial instruments are key to enhancing resilience in the real estate sector.
PhD thesis Lukas Hermwille
‘Guiding the Transformation: The Role of Global Climate Governance as a Facilitator of the Transition of Unsustainable Socio-technical Systems’
Climate change is a transformation challenge. It requires the transformation of a patchwork of independent socio-technical systems. These complex systems have their own specific challenges and path dependencies. Lukas Hermwille introduces a perspective on socio-technical complexity to the study of global climate governance and asks what governance arrangements on the international level, in particular the United Nations Framework Convention of Climate Change (UNFCCC) and its Paris Agreement, can offer to facilitate and foster the required transformational change. His work shows the importance of the discursive power of global climate governance, shifting the expectations and visions of the future of key actors and, as a corollary, changing their investment decisions of today towards a more sustainable future.