scholarly journals The impact of climate change will hit urban dwellers first – Can green infrastructure save us?

2019 ◽  
Author(s):  
Rüdiger Grote
Keyword(s):  
Climate Change ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Heat Waves ◽  
Green Roofs ◽  
Well Being ◽  
Island Effect ◽  
Large Numbers ◽  
Urban Heat ◽  
The Impact

Two phenomena that can cause large numbers of premature human deaths have gained attention in the last years: heat waves and air pollution. These two effects have two things in common: They are closely related to climate change and they are particularly intense in urban areas. Urban areas are particular susceptible to these impacts because they can store lots of heat and have little opportunity for cooling off (also known as the urban heat island effect). In order to mitigate these impacts and to establish an environment that protects human health and improve well-being, implementation of green infrastructure – trees, green walls, and green roofs – is commonly proposed as a remedy. More trees, hedges and lawns are intuitively welcome by people living in cities for their beautifying effects, but to which degree can such greening actually counterbalance the expected effects of climate change? In this review I would like to investigate what science can offer to answer this question.

Forecast-based operation of smart blue-green roofs to reduce the impacts of extreme weather in cities

2021 ◽  
Author(s):  
Tim Busker ◽  
Toon Haer ◽  
Jeroen Aerts ◽  
Hans de Moel ◽  
Bart van den Hurk ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Waves ◽  
Irrigation System ◽  
Green Roofs ◽  
Water Levels ◽  
Added Value ◽  
Environmental Research ◽  
Urban Heat ◽  
The Impact ◽  
The City

<p>Research shows that climate change will increase the intensity and frequency of extreme summer precipitation events as well as heatwaves, over the coming decades (IPCC, 2014; Russo et al., 2015). Moreover, the impact of heat waves will likely increase in cities due to the urban heat island (UHI) effect (Li & Bou-Zeid, 2013). Green infrastructure (e.g. parks, green roofs, etc.) is generally seen as an effective adaptation measure to address these challenges. The city of Amsterdam has started a project (RESILIO, https://resilio.amsterdam/en/smart-blue-green-roofs) to investigate a new innovation in this field: smart blue-green roofs. These roofs have the advantage over green roofs in that they have an extra water retention layer underneath the green layer, which can be used to buffer peak rainfall or as a capillary irrigation system for the plant layer in hot and dry summer days. The smart valve on the roof can be opened when extreme precipitation is predicted to capture extreme rainfall, but it is yet unknown if this forecast-based drainage provides added value to optimize the operation of the valve.</p><p>Therefore, this study evaluates the performance of European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble precipitation forecasts to trigger drainage from blue-green roofs. A conceptual hydrological model of a blue-green roof in Amsterdam is set up to simulate its operation for the last 5 years. Three drainage strategies can be triggered according to different probabilities of precipitation (30<sup>th</sup>, 60<sup>th</sup> and 90<sup>th</sup> percentile) based on ECMWF data. Each strategy is evaluated on how it leads to (1) minimize the overflow during peak rainfall into the city drainage system, and (2) to maintain high water levels during hot summer days to boost evaporative cooling. Preliminary results show that some early drainage strategies result in capturing 50-100% of rainfall (>10mm/hr), while enough water is available on most hot summer days (T>25℃) to ensure atmospheric cooling through plant transpiration. This implies that relatively low-resolution (18km) precipitation forecasts from ECMWF are valuable for anticipatory water management on a very local scale. These results also show the high potential of blue-green roofs for urban climate adaptation, and the need for anticipatory management of these nature-based solutions. The next research steps will include a city-scale roof suitability analysis that will reveal the value of this solution when implemented at most flat roofs in the city of Amsterdam.</p><p>IPCC. (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.</p><p>Li, D., & Bou-Zeid, E. (2013). Synergistic interactions between urban heat islands and heat waves: The impact in cities is larger than the sum of its parts. Journal of Applied Meteorology and Climatology. https://doi.org/10.1175/JAMC-D-13-02.1</p><p>Russo, S., Sillmann, J., & Fischer, E. M. (2015). Top ten European heatwaves since 1950 and their occurrence in the coming decades. Environmental Research Letters. https://doi.org/10.1088/1748-9326/10/12/124003</p>

scholarly journals Experimental Winter Monitoring of a Light-Weight Green Roof Assembly for Building Retrofit

2021 ◽  
Vol 13 (9) ◽  
pp. 4604
Author(s):  
Fabiana Frota de Albuquerque Landi ◽  
Claudia Fabiani ◽  
Anna Laura Pisello
Keyword(s):  
Urban Areas ◽  
Green Roof ◽  
Green Roofs ◽  
Cold Season ◽  
Positive Energy ◽  
Light Weight ◽  
Building Retrofit ◽  
Island Effect ◽  
Urban Heat ◽  
The Impact

Green roofs are a recurrent solution for improving environmental quality in buildings. Such systems can, among other things, reduce the urban heat island effect, improve indoor thermal comfort and visual quality, and reduce energy consumption in buildings, therefore promoting human comfort. This work presents the winter monitoring of a light-weight green roof assembly with the potential to be implemented in extensive urban areas. The green roof monitoring was compared to those of previous bituminous and cool-coating applications. Results show that the system was able to decrease heat losses maintaining a positive energy flow from solar radiation gains and a more constant indoor temperature. In a well-insulated construction, the impact during the cold season was discreet. However, compared to the reference building, a slightly lower indoor air temperature (about 1 °C) was registered.

A review of the adaptation and mitigation of global climate change using sustainable drainage in cities

2010 ◽  
Vol 1 (3) ◽  
pp. 165-180 ◽  
Author(s):  
S. M. Charlesworth
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Urban Areas ◽  
Global Climate ◽  
Green Roofs ◽  
Well Being ◽  
Island Effect ◽  
Engineered Structures ◽  
Quality Water ◽  
The Uk

Sustainable drainage (SUDS) is well known for its equal emphasis on water quality, water quantity, amenity and biodiversity. What is now beginning to be realised is that this approach can also help mitigate the impacts of global climate change (GCC) and provide assistance to city dwellers in adapting to the changes which have already occurred. By using case studies from around the world, this paper illustrates how vegetated SUDS devices can sequester and store carbon, cool urban areas and increase perceptions of health and well-being in the populace. Both vegetated and hard-engineered structures can evaporate water contained within them and are thus being used in cities to cool the overlying air. Also shown is the extent to which SUDS devices such as green roofs and wet pavements are being used to mitigate the urban heat island effect, which, while not caused by climate change, exacerbates its impacts. Of the houses needed by 2040 in the UK, 80% already exist. In order to take advantage of the ability of SUDS to tackle some of the impacts of GCC, the emphasis must be placed on retrofitting technologies to existing buildings and this review proposes a simple hierarchy of suitable measures based on the density and land-use of the built-up area.

scholarly journals The potential of blue-Green infrastructure as a climate change adaptation strategy: a systematic literature review

2021 ◽  
Author(s):  
Tamer Almaaitah ◽  
Madison Appleby ◽  
Howard Rosenblat ◽  
Jennifer Drake ◽  
Darko Joksimovic
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Stormwater Management ◽  
Computer Modelling ◽  
Green Roofs ◽  
Future Research ◽  
Heat Island ◽  
Urban Heat

Abstract Blue-Green Infrastructure (BGI) consists of natural and semi-natural systems implemented to mitigate climate change impacts in urban areas, including elevated air temperatures and flooding. This study is a state-of-the-art review that presents recent research on BGI by identifying and critically evaluating published studies that considered urban heat island mitigation and stormwater management as potential benefits. Thirty-two records were included in the review, with the majority of studies published after 2015. Findings indicate that BGI effectively controls urban runoff and mitigates urban heat, with the literature being slightly more focused on stormwater management than urban heat island mitigation. Among BGI, the studies on blue- and blue-green roofs focused on one benefit at a time (i.e. thermal or hydrologic performance) and did not consider promoting multiple benefits simultaneously. Two-thirds of the selected studies were performed on a large urban scale, with computer modelling and sensor monitoring being the predominant assessment methods. Compared with typical Green Infrastructure (GI), and from a design perspective, many crucial questions on BGI performance, particularly on smaller urban scales, remain unanswered. Future research will have to continue to explore the performance of BGI, considering the identified gaps.

scholarly journals Urban Heat Island in Wuhan and Its Relationship With Nearby Water Bodies

2020 ◽  
Vol 185 ◽  
pp. 02008
Author(s):  
Claire Xu
Keyword(s):  
Urban Heat Island ◽  
Land Surface ◽  
Urban Areas ◽  
Energy Use ◽  
Heat Waves ◽  
Water Bodies ◽  
Heat Island ◽  
Island Effect ◽  
Urban Heat ◽  
The Impact

With predictions of global warming to continue into the near future, heat waves are likely to increase both in frequency and severity. Combined with the fast-developing urban areas and sky-rocketing populations in some regions, urban heat island effect becomes increasingly prominent. This trend has caused numerous problems in energy use, human health, and environmental stress. The purpose of the study in this article is to examine the effects of UHI and its impact on nearby water bodies. Through a series of data, which is collected by using Geospatial visualization tool, the study analyzes the extent to which UHI raises the water temperature in Wuhan, China, and compares lakes in different region of Wuhan to explore the impact of modified land surface and human activities. Given the exacerbation of the urban climatic crisis, the study also presents several potential solutions to a sustainable future in urban areas.

scholarly journals Surface temperature analysis of conventional roof and different use forms of the green roof

2019 ◽  
Vol 28 (4) ◽  
pp. 632-640
Author(s):  
Anna Baryła ◽  
Agnieszka Bus ◽  
Agnieszka Karczmarczyk ◽  
Joanna Witkowska-Dobrev
Keyword(s):  
Green Infrastructure ◽  
Urban Areas ◽  
Imaging System ◽  
Plant Cover ◽  
Effective Means ◽  
Green Roof ◽  
Green Roofs ◽  
Temperature Changes ◽  
Urban Heat ◽  
Thermal Imaging System

Increasing urban populations raises a number of problems and risks that are strengthened by observed and projected climate change. An increase in green areas (so-called green infrastructure) has turned out to be an effective means of lowering temperature in the city. Green roofs can be one of the possible measures leading to achieving this aim. The aim of the study was the analysis of temperature changes of different roof surfaces (conventional roof, board, intensive roof substrate without plant cover, substrate covered with plants (shrubs). Studies on comparing the temperature between a conventional roof and green roofs were carried out in the period from April to September 2015 on the roof of the building of the Faculty of Modern Languages, University of Warsaw. The measurement was performed using the FLIR SC620 thermal imaging system. As a result of the tests, it was found that in the summer months the differences between the temperature of the green roof and the conventional roof amounted to a maximum of 31.3°C. The obtained results showed that the roof with vegetation can signifi cantly contribute to the mitigation of the urban heat island phenomenon in urban areas during summer periods.

Can climate adaptation solutions fix the urban heat island? An assessment of the thermal conditions during heat waves in Vienna impacted by climate change and urban development scenarios for the mid-21st-century

2020 ◽  
Author(s):  
Paul Hamer ◽  
Heidelinde Trimmel ◽  
Philipp Weihs ◽  
Stéphanie Faroux ◽  
Herbert Formayer ◽  
...  
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Heat Wave ◽  
Air Temperature ◽  
Urban Areas ◽  
Climate Adaptation ◽  
Heat Waves ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat

<p>Climate change threatens to exacerbate existing problems in urban areas arising from the urban heat island. Furthermore, expansion of urban areas and rising urban populations will increase the numbers of people exposed to hazards in these vulnerable areas. We therefore urgently need study of these environments and in-depth assessment of potential climate adaptation measures.</p><p>We present a study of heat wave impacts across the urban landscape of Vienna for different future development pathways and for both present and future climatic conditions. We have created two different urban development scenarios that estimate potential urban sprawl and optimized development concerning future building construction in Vienna and have built a digital representation of each within the Town Energy Balance (TEB) urban surface model. In addition, we select two heat waves of similar frequency of return representative for present and future conditions (following the RCP8.5 scenario) of the mid 21<sup>st</sup> century and use the Weather Research and Forecasting Model (WRF) to simulate both heat wave events. We then couple the two representations urban Vienna in TEB with the WRF heat wave simulations to estimate air temperature, surface temperatures and human thermal comfort during the heat waves. We then identify and apply a set of adaptation measures within TEB to try to identify potential solutions to the problems associated with the urban heat island.</p><p>Global and regional climate change under the RCP8.5 scenario causes the future heat wave to be more severe showing an increase of daily maximum air temperature in Vienna by 7 K; the daily minimum air temperature will increase by 2-4 K. We find that changes caused by urban growth or densification mainly affect air temperature and human thermal comfort local to where new urbanisation takes place and does not occur significantly in the existing central districts.</p><p>Exploring adaptation solutions, we find that a combination of near zero-energy standards and increasing albedo of building materials on the city scale accomplishes a maximum reduction of urban canyon temperature of 0.9 K for the minima and 0.2 K for the maxima. Local scale changes of different adaption measures show that insulation of buildings alone increases the maximum wall surface temperatures by more than 10 K or the maximum mean radiant temperature (MRT) in the canyon by 5 K.  Therefore, additional adaptation to reduce MRT within the urban canyons like tree shade are needed to complement the proposed measures.</p><p>This study concludes that the rising air temperatures expected by climate change puts an unprecedented heat burden on Viennese inhabitants, which cannot easily be reduced by measures concerning buildings within the city itself. Additionally, measures such as planting trees to provide shade, regional water sensitive planning and global reduction of greenhouse gas emissions in order to reduce temperature extremes are required.</p><p>We are now actively seeking to apply this set of tools to a wider set of cases in order to try to find effective solutions to projected warming resulting from climate change in urban areas.</p>

scholarly journals Is Smart Growth a smart adaptation strategy?: Examining Ontario's proposed growth under climate change

2004 ◽  
Vol 71 (424-426) ◽  
pp. 57-62
Author(s):  
Brad Bass
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Urban Areas ◽  
Green Roof ◽  
Smart Growth ◽  
Green Roofs ◽  
Adaptation Strategy ◽  
University Of Toronto ◽  
Conducting Research ◽  
The Impact

The author is a member of Environment Canada's Adaptation and Impact Research Group, located in the Centre for Environment at the University of Toronto. His primary research interests include the use of ecological technologies in adapting urban areas to atmospheric change, the impacts of climate change on the energy sector, and the characteristics of adaptable systems. His current work on ecological technologies includes green roofs, vertical gardens and living machines. Dr Bass has been involved in two major projects, in Ottawa and Toronto, to evaluate the impact of green roofs on the urban heat island, energy consumption, stormwater runoff and water quality. Currently, Dr Bass is conducting research on integrating green roof infrastructure with other vegetation strategies at a community scale, simulating the impact of a green roof on the energy consumption of individual buildings.

Analysis of heat wave features and urban heat island effect under climate change

2020 ◽  
Author(s):  
Ye Tian ◽  
Klaus Fraedrich ◽  
Feng Ma
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Air Temperature ◽  
Extreme Events ◽  
Climate Models ◽  
Heat Waves ◽  
Urban Heat Island Effect ◽  
Heat Island ◽  
Island Effect ◽  
Urban Heat

<p>Extreme events such as heat waves occurred in urban have a large influence on human life due to population density. For urban areas, the urban heat island effect could further exacerbate the heat stress of heat waves. Meanwhile, the global climate change over the last few decades has changed the pattern and spatial distribution of local-scale extreme events. Commonly used climate models could capture broad-scale spatial changes in climate phenomena, but representing extreme events on local scales requires data with finer resolution. Here we present a deep learning based downscaling method to capture the localized near surface temperature features from climate models in the Coupled Model Intercomparison Project 6 (CMIP6) framework. The downscaling is based on super-resolution image processing methods which could build relationships between coarse and fine resolution. This downscaling framework will then be applied to future emission scenarios over the period 2030 to 2100. The influence of future climate change on the occurrence of heat waves in urban and its interaction with urban heat island effect for ten most densely populated cities in China are studied. The heat waves are defined based on air temperature and the urban heat island is measured by the urban-rural difference in 2m-height air temperature. Improvements in data resolution enhanced the utility for assessing the surface air temperature record. Comparisons of urban heat waves from multiple climate models suggest that near-surface temperature trends and heat island effects are greatly affected by global warming. High resolution climate data offer the potential for further assessment of worldwide urban warming influences.</p>

Synergistic Interactions between Urban Heat Islands and Heat Waves: The Impact in Cities Is Larger than the Sum of Its Parts

2013 ◽  
Vol 52 (9) ◽  
pp. 2051-2064 ◽  
Author(s):  
Dan Li ◽  
Elie Bou-Zeid
Keyword(s):  
Urban Heat Island ◽  
Rural Areas ◽  
Urban Areas ◽  
Heat Waves ◽  
Mitigation Strategies ◽  
Urban Heat Islands ◽  
Heat Island ◽  
Heat Islands ◽  
Urban Heat ◽  
The Impact

AbstractCities are well known to be hotter than the rural areas that surround them; this phenomenon is called the urban heat island. Heat waves are excessively hot periods during which the air temperatures of both urban and rural areas increase significantly. However, whether urban and rural temperatures respond in the same way to heat waves remains a critical unanswered question. In this study, a combination of observational and modeling analyses indicates synergies between urban heat islands and heat waves. That is, not only do heat waves increase the ambient temperatures, but they also intensify the difference between urban and rural temperatures. As a result, the added heat stress in cities will be even higher than the sum of the background urban heat island effect and the heat wave effect. Results presented here also attribute this added impact of heat waves on urban areas to the lack of surface moisture in urban areas and the low wind speed associated with heat waves. Given that heat waves are projected to become more frequent and that urban populations are substantially increasing, these findings underline the serious heat-related health risks facing urban residents in the twenty-first century. Adaptation and mitigation strategies will require joint efforts to reinvent the city, allowing for more green spaces and lesser disruption of the natural water cycle.

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