Simulating Impacts of Extreme Weather Events on Urban Transport Infrastructure in the UK

Urban areas face many risks from future climate change and their infrastructure will be placed under more pressure due to changes in climate extremes. Using the Tyndall Centre Urban Integrated Assessment Framework, this paper describes a methodology used to assess the impacts of future climate extremes on transport infrastructure in London. Utilising high-resolution projections for future climate in the UK, alongside stochastic weather generators for downscaling, urban temperature and flooding models are used to provide information on the likelihood of future extremes. These are then coupled with spatial network models of urban transport infrastructure and, using thresholds to define the point at which systems cease to function normally, disruption to the networks can be simulated. Results are shown for both extreme heat and urban surface water flooding events and the impacts on the travelling population, in terms of both disruption time and monetary cost

Strengthening the role of civil society in water sector governance towards climate change adaptation in African cities – Durban, Maputo, Nairobi

Water resources management is one of the most important climate change-related issues on international, national and urban public policy agendas. Income inequality in South Africa, Mozambique, and Kenya is among the largest in the world; in all three countries, equity struggles related to water are growing in social, political and ecological significance, which is both a symptom and a cause of urban vulnerabilities related to climate change. Democratic mediation of these conflicts, and sustainable long-term management of water resources in the face of climate change, requires public participation. But those most affected by water issues such as scarcity and flooding are also those least likely to be able to participate in governance and policy institutions. In particular, members of economically disadvantaged groups – especially women, in general – tend to be gravely impacted by poor water management, but also face great difficulties in participating effectively in governance bodies. This project responded to that particular need, and has developed practical strategies for strengthening urban governments in planning investments in climate change adaptation. The project linked university researchers with community-based NGOs conducting environmental education and organizing participatory workshops in low-income urban areas with pressing climate change and water-related problems; built on proven methods of community-university collaboration to strengthen urban watershed governance; increased equity in public participation processes related to urban climate change adaptation; and fostered progressive local, national and international policy development on climate change-related water management – while training students, university researchers, NGO staff members, and community participants. The major research outcome of the project is its contribution to understanding effective ways of strengthening local governments, NGOs and civil society organizations involved in environmental education and organizing for improved public participation in watershed governance and climate change adaptation in African urban areas.This research was supported by the International Development Research Centre, grant number IDRC GRANT NO. 106002-00

No. 08: Climate Change and Food Security in Southern African Cities

The current urban transition in the Global South is at the heart of discussions about the relationship between climate change and food security. This paper explores the links between climate change and food security within the context of the urban transition taking place in Southern Africa. Climate change is expected to negatively accentuate existing levels of urban food insecurity and these adverse impacts are likely to fall disproportionately on the poor. Researchers, planners and policymakers in Southern African cities are starting to explore how changes in weather associated with climate change are likely to affect urban lifestyles and systems. In order to do this, it is important to understand how climate science knowledge is used at the level of the city and how the impacts of climate change might affect city functioning at the metropolitan and household scales. One of the critical areas that has not been addressed in any detail is the extent to which climate change will affect the food security of the city and its inhabitants, especially within the context of high levels of poverty and widespread food and nutrition insecurity. This paper argues that it is important to understand the linkages between climate change and food security in Southern African cities to begin to design and implement pro-poor planning and programming

Influence of street setbacks on solar reflection and air cooling by reflective streets in urban canyons

The ability of a climate model to accurately simulate the urban cooling effect of raising street albedo may be hampered by unrealistic representations of street geometry in the urban canyon. Even if the climate model is coupled to an urban canyon model (UCM), it is hard to define detailed urban geometries in UCMs. In this study, we relate simulated surface air temperature change to canyon albedo change. Using this relationship, we calculate scaling factors to adjust previously obtained surface air temperature changes that were simulated using generic canyon geometries. The adjusted temperature changes are obtained using a proposed multi-reflection urban canyon albedo model (UCAM), avoiding the need to rerun computationally expensive climate models. The adjusted temperature changes represent those that would be obtained from simulating with city-specific (local) geometries. Local urban geometries are estimated from details of the city's building stock and the city's street design guidelines. As a case study, we calculated average citywide seasonal scaling factors for realistic canyon geometries in Sacramento, California based on street design guidelines and building stock. The average scaling factors are multipliers used to adjust air temperature changes previously simulated by a Weather Research and Forecasting model coupled to an urban canyon model in which streets extended from wall to wall (omitting setbacks, such as sidewalks and yards). Sacramento's scaling factors ranged from 2.70 (summer) to 3.89 (winter), demonstrating the need to consider the actual urban geometry in urban climate studies

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

URBAN INDIA AND CLIMATE CHANGE: MITIGATION STRATEGIES TOWARDS INCLUSIVE GROWTH

Climate change has been emerged as a major challenge for the sustainable human settlement. The recent studies have established scientific evidences for climate change. This paper presents impacts of climate change in the urban India, which has about 30 percent of population and expected to grow over 800 million by next 50 years. Citizens are already facing adverse impact of climate change, which is evenly spread throughout the country and mostly to vulnerable citizens. India’s expenditure on adaptation measures was exceeded 2.6 percent of the GDP in 2006-07 shows the magnitude of monetary loss by climate change. Due to complexity of issues, systematic strategies are needed for adaptation and mitigation. In the light of ‘National Action Plan on Climate Change’ two urban sectors viz. urban transportation and municipal solid waste management are assessed and suggestions have been made for mitigation strategies. This study is broadly based on published researches and documents. Findings reveal that yet the climate change is not taken seriously by policy makers, hence blue print for mitigation haven’t placed. Findings suggest systematic mitigation measures for sustainable development which will lead to inclusive growth too. The need for collaborative planning among various stakeholders is emphasized.Climate change, urban India, mitigation, urban transportation, municipal waste management.

Planning for climate change by Queensland coastal councils

The Queensland Coastal Plan requires councils to prepare coastal hazard adaptation plans for those parts of their urban areas at risk from a projected sea level rise of 80cm by 2100. This paper reviews adaptation actions in climate change strategies prepared by four urban Queensland coastal councils (e.g. Cairns, Gold Coast, Redland, and Sunshine Coast), and one community-based climate adaptation action plan for Bribie Island in Moreton Bay. The actions in these climate change plans are analysed for their adaptive response categories: Emphasising Nature, Emphasising Development and Managed Nature (Vasey-Ellis, 2009), along with Council Governance of climate change, and Emphasising Communities. Climate change planning and infrastructure responses by Queensland coastal councils mainly focus on protecting coastal development from erosion and other climate hazards, and building community resilience, supplemented by ‘soft’ environmental actions protecting nature. While some climate plans included actions for shoreline erosion, coastal inundation, and storm surges, only one addressed sea level rise impacts on buildings and heritage (i.e. Redland)

Management of an Urban Stormwater System Using Projected Future Scenarios of Climate Models: A Watershed-Based Modeling Approach

Anticipating a proper management needs for urban stormwater due to climate change is becoming a critical concern to water resources managers. In an effort to identify best management practices and understand the probable future climate scenarios, this study used high-resolution climate model data in conjunction with advanced statistical methods and computer simulation. Climate model data from the North American Regional Climate Change Assessment Program (NARCCAP) were used to calculate the design storm depths for the Gowan Watershed of Las Vegas Valley, Nevada. The Storm Water Management Model (SWMM), developed by the Environmental Protection Agency (EPA), was used for hydrological modeling. Two low-impact development techniques – Permeable Pavement and Green Roof – were implemented in the EPA SWMM hydrological modeling to attenuate excess surface runoff that was induced by climate change. The method adopted in this study was effective in mitigating the challenges in managing changes in urban stormwater amounts due to climate change

Including the urban heat island in spatial heat health risk assessment strategies: a case study for Birmingham, UK

Background Heatwaves present a significant health risk and the hazard is likely to escalate with the increased future temperatures presently predicted by climate change models. The impact of heatwaves is often felt strongest in towns and cities where populations are concentrated and where the climate is often unintentionally modified to produce an urban heat island effect; where urban areas can be significantly warmer than surrounding rural areas. The purpose of this interdisciplinary study is to integrate remotely sensed urban heat island data alongside commercial social segmentation data via a spatial risk assessment methodology in order to highlight potential heat health risk areas and build the foundations for a climate change risk assessment. This paper uses the city of Birmingham, UK as a case study area. Results When looking at vulnerable sections of the population, the analysis identifies a concentration of "very high" risk areas within the city centre, and a number of pockets of "high risk" areas scattered throughout the conurbation. Further analysis looks at household level data which yields a complicated picture with a considerable range of vulnerabilities at a neighbourhood scale. Conclusions The results illustrate that a concentration of "very high" risk people live within the urban heat island, and this should be taken into account by urban planners and city centre environmental managers when considering climate change adaptation strategies or heatwave alert schemes. The methodology has been designed to be transparent and to make use of powerful and readily available datasets so that it can be easily replicated in other urban areas