Spatiotemporal assessment of heat risk for high-density urban areas: a case study in Dublin, Ireland

2021 ◽  
Author(s):  
Barry O'Dwyer ◽  
Roberta Paranunzio ◽  
Edward Dwyer
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Urban Areas ◽  
Spatial Planning ◽  
Radiative Forcing ◽  
Climate Index ◽  
Spatially Explicit ◽  
Urban Heat ◽  
Heat Risk ◽  
Projected Changes

<p>Ireland’s climate is changing and these changes are projected to intensify into the future posing an increasing risk to Ireland’s environment, society and economy. For Ireland and its urban areas in particular, projected changes in the frequency and intensity of heatwaves is considered a moderate but real risk. For example, it is considered likely that Ireland’s capital city Dublin will experience increases in the frequency and intensity of heatwaves under projected climate change. Moreover Ireland’s population is ageing faster than other parts of Europe and becoming increasingly vulnerable to heat stress.</p><p>To date, little attention has focussed on heat-related risks for Ireland’s urban areas, focussing primarily on risks associated with sea level rise and changing patterns of precipitation. Through this work, we provide an innovative approach that allows for the integrated assessment of current and future heat risk for the Greater Dublin Area.  Employing a range of modelling approaches, landcover projections have been developed and future changes in urban heat projected, and spatiotemporal variations in level of exposure to heat stress have been calculated using the Universal Thermal Climate Index (UTCI) for current and future periods (2020s – 2050s) under a range of radiative forcing scenarios (RCP4.5 and 8.5).  These assessments are combined with vulnerability information (socio-economic data) to obtain spatially-explicit indexes of heat risk and for different scenarios (RCPs). As a result of projected changes in landcover and temperatures, our assessments show that the level of exposure to extreme heat stress will increase in the coming decades and this is particularly the case for the RCP 8.5 scenario. In combination with assessments of vulnerability, this study identifies significant spatial clusters in the denser urban core of the city and peri-urban areas that are considered to be at relatively high levels of heat risk.</p><p>Spatial planning and land use planning are emerging as policy areas that can have significant influence on adaptation to and mitigation of climate change. Through spatial planning, the ways in which cities are designed in order to minimise risks can be re-evaluated and the complexity and uncertainty of climate change tackled.  This study provides spatially explicit information at a fine scale on the evolution of exposure and vulnerability related to thermal heat stress that will support stakeholders to implement strategies and policies aimed at mitigating and adapting to ongoing and future urban heat risk.  </p><div> </div>

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 Future Changes in Human-Biometeorological Index Classes in Three Regions of Luxembourg, Western-Central Europe

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Stress ◽  
Thermal Comfort ◽  
Central Europe ◽  
Spatial Resolution ◽  
Climate Index ◽  
Human Thermal Comfort ◽  
Air Temperatures ◽  
The Impact

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.

scholarly journals Climate-change risk analysis for global urban forests

2021 ◽  
Author(s):  
Manuel Esperon-Rodriguez ◽  
John B Baumgartner ◽  
Linda J Beaumont ◽  
Jonathan Lenoir ◽  
David A Nipperess ◽  
...  
Keyword(s):  
Climate Change ◽  
At Risk ◽  
Urban Areas ◽  
Safety Margin ◽  
Urban Forests ◽  
Economic Benefits ◽  
Mean Annual Temperature ◽  
Vulnerability To Climate Change ◽  
Projected Changes ◽  
Impacts Of Climate Change

Urban forests (i.e. all vegetation present in urban areas), provide environmental and socio-economic benefits to more than half of the global population. Projected climate change threatens these benefits to society. Here, we assess vulnerability to climate change of 16,006 plant species present in the urban forests of 1,010 cities within 93 countries, using three vulnerability metrics: exposure, safety margin and risk. Exposure expresses the magnitude of projected changes in climate in a given area, safety margin measures species' sensitivity to climate change, and risk is the difference between exposure and safety margin. We identified 9,676 (60.5%) and 8,344 (52.1%) species exceeding their current climatic tolerance (i.e. safety margin) for mean annual temperature (MAT) and annual precipitation (AP), respectively. By 2050, 13,479 (84.2%) and 9,960 (62.2%) species are predicted to be at risk from projected changes in MAT and AP, respectively, with risk increasing in cities at lower latitudes. Our results can aid evaluation of the impacts of climate change on urban forests and identify the species most at risk. Considering future climates when selecting species for urban plantings will enhance the long-term societal benefits provided by urban forests, including their contribution to mitigating the magnitude and impacts of climate change.

scholarly journals Climate Change and Thermal Comfort in Top Tourist Destinations—The Case of Santorini (Greece)

2021 ◽  
Vol 13 (16) ◽  
pp. 9107
Author(s):  
George Katavoutas ◽  
Dimitra Founda ◽  
Gianna Kitsara ◽  
Christos Giannakopoulos
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Environment ◽  
Stress Conditions ◽  
Climate Index ◽  
Mitigation Scenario ◽  
Future Projections ◽  
Tourist Destinations ◽  
The Future ◽  
The Mediterranean

The Mediterranean area is one of the most visited tourist destinations of the world, but it has also been recognized as one of the most vulnerable to climate change areas worldwide with respect to increased thermal risk. The study focuses on a top worldwide tourist destination of the Mediterranean, Santorini Island in Greece, and aims to assess the past, present and future thermal environment in the island based on the advanced Universal Thermal Climate Index (UTCI). The study utilizes historical observations capturing past (late 19th to early 20th century) and more recent (1982–2019) time periods, while future projections are realized based on four regional climate models (RCMs) under the weak mitigation scenario (RCP4.5) and the non-mitigation scenario with high emissions (RCP8.5). The frequency of cold stress conditions at midday decreases during winter and early spring months by up to 19.8% (January) in the recent period compared to the historical one, while heat stress conditions increase in summer by up to 22.4% (August). Future projections suggest progressive shifts of the UTCI towards higher values in the future and an increase in the exposure time under heat stress depending on the RCM and adopted scenario. The increase in moderate and strong heat stress conditions is mainly expected during the summer months (June, July, August); nevertheless, a noticeable increase is also foreseen in September and May. The highest occurrences of favorable (no thermal stress) conditions are also projected to shift by one month, from June to May and from September to October, in the future.

scholarly journals Pet Welfare in Municipal Adaptation Plans: Case of Poland

2021 ◽  
Vol 30 (3) ◽  
pp. 95-107
Author(s):  
Anna Haładyj ◽  
Katarzyna Kułak-Krzysiak
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Comfort ◽  
Urban Heat Islands ◽  
Adaptation Measures ◽  
Main Hypothesis ◽  
Heat Islands ◽  
Starting Point ◽  
Legal Nature ◽  
Urban Heat

The aim of the article was to explore pet welfare in Municipal Adaptation Plans (MAPs), based on a literature review and case studies of 40 MAPs accepted in Poland as part of the “Let’s Feel the Climate” project, supported by the Polish Ministry of Environment in 2017–2019. The study summarizes the concept of climate change and the importance of adaptation measures with particular emphasis on urban heat islands and heat stress, acknowledged by climate change literature, and outlines pet welfare in the context of thermal comfort and threats caused by heat stress. Because the authors subsequently presented an empirical study of the 40 accepted MAPs, they also discussed the role and legal nature of MAPs. The main hypothesis of this survey of Polish MAPs was that pet welfare in the context of their thermal comfort is an example of the adaptive measures clearly stipulated in Polish MAPs, which was examined after presenting the MAPs’ findings. The starting point was the assumption that the welfare of pets should also be assessed from the perspective of their thermal comfort – a new element of broadly understood animal welfare. This is due to the fact that pets are exposed to the risk of heat stress resulting from urban heat islands and, just like people, have to endure the inconvenience of extreme weather phenomena, which is impossible without the support of amenities such as drinkers or water shelters and the development of green and blue infrastructure.

Automated detection of urban heat islands based on satellite imagery, digital surface models, and a low-cost sensor network                                     

2021 ◽  
Author(s):  
Sebastian Schlögl ◽  
Nico Bader ◽  
Julien Gérard Anet ◽  
Martin Frey ◽  
Curdin Spirig ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Rural Areas ◽  
Urban Areas ◽  
Low Cost ◽  
Urban Heat Islands ◽  
Heat Islands ◽  
Micro Scale ◽  
Air Temperatures ◽  
Urban Heat

<p>Today, more than half of the world’s population lives in urban areas and the proportion is projected to increase further in the near future. The increased number of heatwaves worldwide caused by the anthropogenic climate change may lead to heat stress and significant economic and ecological damages. Therefore, the growth of urban areas in combination with climate change can increase future mortality rates in cities, given that cities are more vulnerable to heatwaves due to the greater heat storage capacity of artificial surfaces towards higher longwave radiation fluxes.</p><p>To detect urban heat islands and resolve the micro-scale air temperature field in an urban environment, a low-cost air temperature network, including 450 sensors, was installed in the Swiss cities of Zurich and Basel in 2019 and 2020. These air temperature data, complemented with further official measurement stations, force a statistical air temperature downscaling model for urban environments, which is used operationally to calculate hourly micro-scale air temperatures in 10 m horizontal resolution. In addition to air temperature measurements from the low-cost sensor network, the model is further forced by albedo, NDVI, and NDBI values generated from the polar-orbiting satellite Sentinel-2, land surface temperatures estimated from Landsat-8, and high-resolution digital surface and elevation models.</p><p>Urban heat islands (UHI) are processed averaging hourly air temperatures over an entire year for each grid point, and comparing this average to the overall average in rural areas. UHI effects can then be correlated to high-resolution local climate zone maps and other local factors.</p><p>Between 60-80 % of the urban area is modeled with an accuracy below 1 K for an hourly time step indicating that the approach may work well in different cities. However, the outcome may depend on the complexity of the cities. The model error decreases rapidly by increasing the number of spatially distributed sensor data used to train the model, from 0 to 70 sensors, and then plateaus with further increases. An accuracy below 1 K can be expected for more than 50 air temperature measurements within the investigated cities and the surrounding rural areas. </p><p>A strong statistical air temperature model coupled with atmospheric boundary layer models (e.g. PALM-4U, MUKLIMO, FITNAH) will aid to generate highly resolved urban heat island prediction maps that help decision-makers to identify local heat islands easier. This will ensure that financial resources will be invested as efficiently as possible in mitigation actions.</p>

scholarly journals Guidance to Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island

2021 ◽  
Author(s):  
K. Heinke Schluenzen ◽  
Sue Grimmond ◽  
Alexander Baklanov
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Global Climate ◽  
Heat Island ◽  
Canopy Layer ◽  
Second Person ◽  
Urban Heat ◽  
The Many ◽  
Definition Of

<p>Today, every second person lives in a city, and urbanization is continuously increasing. For 2050, it is to be expected that 2 out of 3 people will live in a city and thus the vast majority of the world's population will be affected not only by global climate change but also by locally induced climatic changes. The canopy layer urban heat island (CL-UHI) is one of the most well-known meteorological characteristics of urban areas found in cities small and large around the world. Its characteristics differ between cities, across a city and with time. The climate change induced warming cities experience is additionally impacted by the CL-UHI.</p><p>Despite the city-scale importance of CL-UHI, the WMO has not had any specific guidance on this. In response to the request of the 18th World Meteorological Congress (Resolutions 32 and 61) experts from WMO GAW (Global Atmosphere Watch) Urban Research Meteorology and Environment (GURME) initiated in 2020 preparation of a guidance on measuring, modelling and monitoring the CL-UHI. The guidance is a community-based development with 30 contributors providing expertise in all different aspects of CL-UHI. This includes a clear definition of what a CL-UHI is and clarifications of what it is not, how it develops (e.g. meteorological and morphological influences), methods to assess CL-UHI intensities (measurements,  modelling approaches) as well as when its assessment  (applications) is needed and how it can be reduced (or when it is beneficial).</p><p>The presentation will specifically focus on the key questions addressed in the guidance: what a CL-UHI is and what it is not, where CL-UHI values are relevant for and the many challenges that exist in simulating the CL-UHI with different models.</p>

scholarly journals Global long-term mapping of surface temperature shows intensified intra-city urban heat island extremes

2021 ◽  
Author(s):  
Lorenzo Mentaschi ◽  
Gregory Duveiller ◽  
Grazia Zulian ◽  
Christina Corbane ◽  
Martino Pesaresi ◽  
...  
Keyword(s):  
Heat Stress ◽  
Surface Temperature ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Human Impacts ◽  
Warm Season ◽  
Mitigation Strategies ◽  
Heat Island ◽  
Urban Heat

Abstract Surface temperatures are generally higher in cities than in rural surroundings. This phenomenon, known as surface urban heat island (SUHI), increases the risk of heat-related human illnesses and mortality. Past global studies analysed this phenomenon aggregated at city scale or over seasonal and annual time periods, while human impacts strongly depend on shorter term heat stress experienced locally. Here we develop a global long-term high-resolution dataset of daytime SUHI as urban-rural surface temperature differences. Our results show that across urban areas worldwide over the period 2003-2020, 3-day SUHI extremes are on average more than twice as high as the warm-season median SUHI, with local exceedances up to 10 K. Over this period, SUHI extremes have increased more rapidly than warm-season medians, and averaged worldwide are now 1.04 K or 31% higher compared to 2003. This can be linked with increasing urbanisation, more frequent heatwaves, and greening of the earth, processes that are all expected to continue in the coming decades. Within many cities there are hotspots where extreme SUHI intensity is 10 to 15 K higher compared to relatively cooler city parts. Given the limited human adaptability to heat stress, our results advocate for mitigation strategies targeted at reducing SUHI extremes in the most vulnerable and exposed city neighbourhoods.

scholarly journals Future Climate Change Impact on Urban Heat Island in Two Mediterranean Cities Based on High-Resolution Regional Climate Simulations

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 884
Author(s):  
Stavros Ch. Keppas ◽  
Sofia Papadogiannaki ◽  
Daphne Parliari ◽  
Serafim Kontos ◽  
Anastasia Poupkou ◽  
...  
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Climate Change Impact ◽  
Urban Areas ◽  
Weather Prediction ◽  
Future Climate ◽  
Future Climate Change ◽  
Heat Island ◽  
Urban Heat ◽  
Change Impact

The Mediterranean is recognized among the most responsive regions to climate change, with annual temperatures projected to increase by 1–5 °C until 2100. Large cities may experience an additional stress discomfort due to the Urban Heat Island (UHI) effect. In the present study, the WRF-ARW numerical weather prediction model was used to investigate the climate change impact on UHI for two Mediterranean cities, Rome and Thessaloniki. For this purpose, three 5-year time-slice simulations were conducted (2006–2010, 2046–2050, 2096–2100) under the Representative Concentration Pathway (RCP) 8.5 emission scenario, with a spatial resolution of 2 km. In order to comprehensively investigate the urban microclimate, we analyze future simulation data across sections crossing urban/non-urban areas, and after grouping them into three classes depending on the location of the grid cells. The urban areas of both cities present increased average minimum temperature (Tmin) in winter/summer compared to other rural areas, with an UHI of ~+1.5–3 °C on average at night/early morning. Considering UHI under future climate change, we found no significant variations (~±0.2 °C). Finally, we found that the numbers of days with Tmin ≥ 20 °C will mostly increase in urban coastal areas until 2100, while the largest increase of minimum Discomfort Index (DImin) is expected in urban low-ground areas.

Sign in / Sign up

Export Citation Format

Share Document