Climate resilience remains a crucial goal for the built environment. Our ancestors successfully inhabited some of the Earth's harshest climates, from the Arctic to deserts. If they could overcome such challenges, why should our high-tech society fail?

In a white paper, the 4TU Domain Acceleration Team (DAT) on Climate Adaptation and Mitigation, composed of members from four technical universities in the Netherlands, examines why modern societies struggle to achieve climate adaptation and mitigation targets.

While mitigation efforts, such as reducing CO2 emissions, have clear, universally agreed-upon goals, adaptation efforts tend to be local and lack established targets and benchmarks, making progress challenging to track.

Climate mitigation and adaptation measures in the built environment are interdependent, requiring careful coordination to avoid inefficiencies or counterproductive outcomes. For instance, the energy transition (climate mitigation) demands major infrastructure changes, while climate adaptation requires significant urban modifications and underground work. These efforts must align to ensure resilient and future-proof inhabitancy of urban areas; without integration, some measures may hinder or negate the benefits of others.

A key challenge is the lack of cross-sector collaboration. Different sectors—energy, climate, mobility—operate under distinct frameworks, policies, and timelines, complicating the implementation of solutions. The shortage of skilled professionals in the Netherlands limits the capacity for cross-sector collaboration, as many lack expertise to navigate both climate and energy sectors, as well as spatial planning policy.

Similarly, while spatial analysis tools such as Klimaateffectatlas and Toolbox Klimaatadaptatie exist, they typically focus on individual challenges like mitigation or adaptation. There is a critical need for also integrating tools that assess the spatial implications of policy goals across sectors, and temporal scales.

The white paper addresses these challenges and explores potential cross-disciplinary synergies, aiming to drive innovative solutions for future climate resilience, where climate adaptation and mitigation always go hand in hand.

Accessibility is a key concept in transport and land use policies, and infrastructure-based measures are one important category of accessibility measures. Recently, there has been a significant increase in the attention paid in both academic literature and policy documents to the robustness of the transport system. However, there is not a mature body of literature on the infrastructure-based accessibility measures expressing this concept. This paper proposes a family of accessibility measures to express the robustness of the transport system. These have in common that they express the number of travel options between a given origin and destination, or to conduct activities. The family of measures is conceptualized by using the multi-state supernetwork approach. With respect to the travel options, we discuss (1) the overlap of travel routes, and (2) the choices of travel modes (e.g. car versus train; multimodal). With respect to the activities, we discuss (1) the choice of OD pairs as opposed to activity-travel patterns, and (2) fixed versus flexible activity locations and fixed versus flexible order of activities. We illustrate the travel options and robustness in a multi-modal transport system between the city centers of the Hague-Rotterdam-Dordrecht corridor (The Netherlands).