Contrasting Adaptation Measures: Developing Plans for Urban Greening Against Heat in the Interface between Climate Modelling and Stakeholder Participation

The Lisbon Metropolitan Area (AML), located in the Mediterranean region, is particularly vulnerable to climate hazards, such as extreme temperatures. In particular, the concentration of population in this urban area has largely increased the exposure to the urban heat island effect (UHI) and heatwaves are posing substantial challenges to human health, infrastructures and energy systems, and human and land productivity. At the same time, adaptation planning at local scales and higher resolutions lacks wide and publicly available climate data to ensure an evidence-based approach. Similarly, the efficiency of measures of greening the urban fabric to respond to heat extremes lacks a sufficient quantification, resulting in possible mismatches between policy imperatives, climate change and the results of adaptation actions.
We investigate how the development of urban greening plans by urban planners and region- and city-scale stakeholders can assist in the decrease of heat stress for the metropolitan area and in two selected neighbourhoods in the municipalities of Lisbon and Almada. Using the climate model UrbClim to project urban heat stress at a 100- and 1-meter resolution, we identify particular areas of concern. Together with stakeholders and urban planners we connected the results of the heat stress modelling with existing policies and plans, as well as with planning and design principles for urban resilience to heat.
Through establishing a set of policy statements for the degree and configuration of greening measures, we model the efficiency of different adaptation actions according to global climate scenarios. The interoperability between climate modelling, urban planning and stakeholder participation, that is, the linkage between land-use/land-cover, urban planning and design principles and climate modelling, allows planners and stakeholders to explore different degrees (and specific designs) of greening measures and match them against the scenarios whose impacts they want to prioritize.