Spatial characterisation of heat risk in the Brussels Capital Region, Belgium

Urban residents are exposed to higher levels of heat stress in comparison to the rural population. For the city of Brussels, we explore the influence of urban planning and global greenhouse gas emissions (GHG) for the near (2031-2050) and far (2081-2100) future. We implemented two urban planning expansion scenarios (translated into Local Climate Zones, LCZ) and two Representative Concentration Pathways (RCPs 4.5 and 8.5). The projections show that the influence of GHG emissions trumps urban planning measures in each of the two periods. In the near future, no large differences are noted between the RCP scenarios. In the far future on the contrary, both heat stress and risk values are twice as large for RCP 8.5 compared to RCP 4.5. Depending on the GHG scenario and the LCZ, heat stress is projected to increase with a factor of 10 by 2090 compared to the present-day climate and urban planning conditions. The imprint of vulnerability and exposure is clearly visible in the heat risk assessment, leading to very high levels of heat risk most notable for the northwestern part of the Brussels Capital Region (BCR). The results demonstrate the need for mitigation and adaptation plans at different policy levels that strive for lower GHG emissions and the development of sustainable urban areas safeguarding livability in future cities.