Heat risk assessment for the Brussels capital region under different urban planning and greenhouse gas emission scenarios

Urban residents are exposed to higher levels of heat stress in comparison to the rural population. As this phenomenon could be enhanced by both global greenhouse gas emissions (GHG) and urban expansion, urban planners and policymakers should integrate both in their assessment. One way to consider these two concepts is by using urban climate models at a high resolution. In this study, the influence of urban expansion and GHG emission scenarios is evaluated at 100 m spatial resolution for the city of Brussels (Belgium) in the near (2031-2050) and far (2081-2100) future. Two possible urban planning scenarios (translated into local climate zones, LCZs) in combination with two representative concentration pathways (RCPs 4.5 and 8.5) have been implemented in the urban climate model UrbClim. The projections show that the influence of GHG emissions trumps urban planning measures in each period. In the near future, no large differences are seen between the RCP scenarios; in the far future, 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 type, heat stress is projected to increase by 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 notably for the North Western part of the Brussels Capital Region. 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 cities

Criterion for explosive percolation transitions on complex networks

In a recent Letter, Friedman and Landsberg discussed the underlying mechanism of explosive phase transitions on complex networks [Phys. Rev. Lett. 103, 255701 (2009)]. This Brief Report presents a modest, though more insightful extension of their arguments. We discuss the implications of their results on the cluster-size distribution and deduce that, under general conditions, the percolation transition will be explosive if the mean number of nodes per cluster diverges in the thermodynamic limit and prior to the transition threshold. In other words, if, upon increase of the network size n the amount of clusters in the network does not grow proportionally to n, the percolation transition is explosive. Simulations and analytical calculations on various models support our findings

Lessons Learned from Applying Adaptation Pathways in Heatwave Risk Management in Antwerp and Key Challenges for Further Development

Heat exposure is a well-known health hazard, which causes several problems ranging from thermal discomfort or productivity reduction to the aggravation of existing illnesses and death. Climate projections foresee an increase in the frequency and intensity of heat-related impacts on human health. To reduce these climate risks, governments need a better understanding of not only the scale and the factors affecting those risks, but also how to prepare and protect the city and citizens against these risks and prevent them through effective policy making. Therefore, climate adaptation decisions need to be made in complex systems with manifold uncertainties. In response to these deep uncertainties, different planning approaches have been developed to assist policymakers in decision making. This paper is focused on one of the dynamic adaptive policy planning approaches: the adaptation pathway. This approach allows designing alternative feasible plans that are flexible and can respond when new information appears or when conditions in the environment change. This paper presents a structured methodology for designing adaptation pathways. The work describes a high-level adaptation pathway covering heatwave impacts on productivity and health at city level in Antwerp to ensure the city adapts to future conditions. Lastly, a summary is provided of the lessons learned and the challenges of this approach are discussed.This work was supported by the European Community’s Seventh Framework Programme (grant agreement no. 308497), Project RAMSES “Reconciling Adaptation, Mitigation and Sustainable Development for Cities” (2012–2017). In addition, this study has received partial funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 653522 (RESIN−Climate Resilient Cities and Infrastructures project)

Advantages of using a fast urban boundary layer model as compared to a full mesoscale model to simulate the urban heat island of Barcelona

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A new method to assess fine-scale outdoor thermal comfort for urban agglomerations

In urban areas, high air temperatures and heat stress levels greatly affect human thermal comfort and public health, with climate change further increasing the mortality risks. This study presents a high resolution (100 m) modelling method, including detailed offline radiation calculations, that is able to efficiently calculate outdoor heat stress for entire urban agglomerations for a time period spanning several months. A dedicated measurement campaign was set up to evaluate model performance, yielding satisfactory results. As an example, the modelling tool was used to assess the effectiveness of green areas and water surfaces to cool air temperatures and wet bulb globe temperatures during a typical hot day in the city of Ghent (Belgium), since the use of vegetation and water bodies are shown to be promising in mitigating the adverse effects of urban heat islands and improving thermal comfort. The results show that air temperature reduction is most profound over water surfaces during the afternoon, while open rural areas are coolest during the night. Radiation shading from trees, and to a lesser extent, from buildings, is found to be most effective in reducing wet bulb globe temperatures and improving thermal comfort during the warmest moments of the day

Projected heat-related mortality under climate change in the metropolitan area of Skopje

Abstract Background Excessive summer heat is a serious environmental health problem in Skopje, the capital and largest city of the former Yugoslav Republic of Macedonia. This paper attempts to forecast the impact of heat on mortality in Skopje in two future periods under climate change and compare it with a historical baseline period. Methods After ascertaining the relationship between daily mean ambient air temperature and daily mortality in Skopje, we modelled the evolution of ambient temperatures in the city under a Representative Concentration Pathway scenario (RCP8.5) and the evolution of the city population in two future time periods: 2026–2045 and 2081–2100, and in a past time period (1986–2005) to serve as baseline for comparison. We then calculated the projected average annual mortality attributable to heat in the absence of adaptation or acclimatization during those time windows, and evaluated the contribution of each source of uncertainty on the final impact. Results Our estimates suggest that, compared to the baseline period (1986–2005), heat-related mortality in Skopje would more than double in 2026–2045, and more than quadruple in 2081–2100. When considering the impact in 2081–2100, sampling variability around the heat–mortality relationship and climate model explained 40.3 and 46.6 % of total variability. Conclusion These results highlight the importance of a long-term perspective in the public health prevention of heat exposure, particularly in the context of a changing climate

Applications of Models and Tools for Mesoscale and Microscale Thermal Analysis in Mid-Latitude Climate Regions—A Review

Urban analysis at different spatial scales (micro- and mesoscale) of local climate conditions is required to test typical artificial urban boundaries and related climate hazards such as high temperatures in built environments. The multitude of finishing materials and sheltering objects within built environments produce distinct patterns of different climate conditions, particularly during the daytime. The combination of high temperatures and intense solar radiation strongly perturb the environment by increasing the thermal heat stress at the pedestrian level. Therefore, it is becoming common practice to use numerical models and tools that enable multiple design and planning alternatives to be quantitatively and qualitatively tested to inform urban planners and decision-makers. These models and tools can be used to compare the relationships between the micro-climatic environment, the subjective thermal assessment, and the social behaviour, which can reveal the attractiveness and effectiveness of new urban spaces and lead to more sustainable and liveable public spaces. This review article presents the applications of selected environmental numerical models and tools to predict human thermal stress at the mesoscale (e.g., satellite thermal images and UrbClim) and the microscale (e.g., mobile measurements, ENVI-met, and UrbClim HR) focusing on case study cities in mid-latitude climate regions framed in two European research projects.The work leading to these results has received funding from the European Community’s Seventh Framework Programme under Grant Agreement No. 308497, Project RAMSES—Reconciling Adaptation, Mitigation, and Sustainable Development for Cities (2012–2017) and from the European Union’s H2020 Research and Innovation Programme under Grant Agreement No. 73004 (PUCS/Climate-fit.city). The APC was funded by the Research Group of Building and Technology, De partment of Civil and Environmental Engineering, Norwegian University of Science and Technolog

FAIRMODE Intercomparison exercise - Dataset to assess the area of representativeness of Air Quality Monitoring Stations

A feasibility study for organizing an intercomparison exercise (IE) of the methods used for estimating of the area of representativeness of the Air Quality Monitoring Stations (SR) in Europe has been carried out. It showed that it should be possible to compare the extent of SR determined by the different methods. Moreover, at the FAIRMODE-Aveiro meeting in 2015, the participants agreed to carry out the intercomparison exercise assessing the SR estimates for PM10 and NO2 at one traffic station, and for PM10, NO2 and O3 at two urban background stations. This report presents a dataset suitable for the FAIRMODE IE of the area of representativeness of Air Quality Monitoring Stations in the urban area of Antwerp (Belgium) for the year 2012. Three monitoring stations, Borgerhout-Straatkant, Antwerpen-Linkeroever and Schoten, have been selected for the evaluation. The dataset includes the model results for interpolated annual means on a fine regular grid, hourly time series at a number of 341 virtual receptor points to which random noise have been added, data from measurements of the Antwerp automatic monitoring stations, individual sampling campaigns, emissions, traffic, population density, building information, gridded CORINE land cover data, a short summary of PM10 speciated data and daily time profiles for traffic.JRC.C.5-Air and Climat