Implications of the urban heat island and global climate change and nutritional status on the human thermal comfort in Mexico City

2021 ◽  
Author(s):  
Victor L Barradas ◽  
Monica Ballinas
Keyword(s):  
Climate Change ◽  
Nutritional Status ◽  
Thermal Comfort ◽  
Mexico City ◽  
Global Climate Change ◽  
Global Climate ◽  
Overweight And Obesity ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat

<p>The urban heat island (UHI) is mostly due to urbanization and it is considered as a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI in concert with the high temperatures caused by global climate change (CC) may profoundly affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. Obesity is a disease manifested by the accumulation of excess body fat with implications for the health of people, and Mexico ranks first in overweight and obesity, where 30% of the population has obesity and near 40% is overweight. The main objective of this investigation was to determine the changes in the degree of thermal comfort of Mexico City inhabitants according to their nutritional status, because of the increase in temperatures due UHI and CC. A series of microclimatological measurements to estimate the physiologically equivalent temperature (PET) were made. Concomitantly, a series of surveys of thermal perception were applied to 1300 passersby. The results show that PET has increased from 1990 to 2010 from 0.0372 °C/year to 0.0887 °C/year in the study sites, besides overestimating the degree of thermal comfort of people with normal weight but underestimating that of overweight and obese people according to the stablished categories or classes. It is concluded that it is imperative that people with overweight and obesity reduce their weight but also should be investigated that influences the unbalanced consumption of food. It is also imperative to mitigate UHI and CC through urban architectural techniques.</p>

OVERVIEW OF URBAN HEAT ISLAND (UHI) PHENOMENON TOWARDS HUMAN THERMAL COMFORT

2017 ◽  
Vol 16 (9) ◽  
pp. 2097-2111 ◽  
Author(s):  
Mohanadoss Ponraj ◽  
Yee Yong Lee ◽  
Mohd Fadhil Md Din ◽  
Zainura Zainon Noor ◽  
Kenzo Iwao ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat

Climate Change and the Health of Urban Populations

Urban Health ◽  
2019 ◽  
pp. 129-138
Author(s):  
Patrick L. Kinney
Keyword(s):  
Climate Change ◽  
Urban Health ◽  
Global Climate Change ◽  
Global Climate ◽  
Urban Resilience ◽  
Urban Populations ◽  
The World ◽  
The Face ◽  
Urban Heat ◽  
Risk Of Exposure

Global climate change represents one of the sentinel changes the world is facing and that will threaten population health in this century. In the context of urban health, climate change threatens to increase urban heat island effects, to change exposure to pollution, and to increase urban residents’ risk of exposure to natural disasters, among other phenomena. And yet urban innovation is central to the longer term solution to climate change from the development of innovative approaches that reduce cities’ carbon footprint to initiatives that increase urban resilience in the face of climate change threats. This chapter discusses the threat that climate change poses for urban populations and potential approaches that can mitigate this challenge toward improving urban health.

scholarly journals Green Infrastructure as an Urban Heat Island Mitigation Strategy—A Review

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3577
Author(s):  
Fatma Balany ◽  
Anne WM Ng ◽  
Nitin Muttil ◽  
Shobha Muthukumaran ◽  
Man Sing Wong
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Green Infrastructure ◽  
Mitigation Strategies ◽  
Heat Island ◽  
Recent Past ◽  
Simulation Tools ◽  
Human Thermal Comfort ◽  
Different Types ◽  
Urban Heat

Research on urban heat mitigation has been growing in recent years with many of the studies focusing on green infrastructure (GI) as a strategy to mitigate the adverse effects of an urban heat island (UHI). This paper aims at presenting a review of the range of findings from GI research for urban heat mitigation through a review of scientific articles published during the years 2009–2020. This research includes a review of the different types of GI and its contribution for urban heat mitigation and human thermal comfort. In addition to analysing different mitigation strategies, numerical simulation tools that are commonly used are also reviewed. It is seen that ENVI-met is one of the modelling tools that is considered as a reliable to simulate different mitigation strategies and hence has been widely used in the recent past. Considering its popularity in urban microclimate studies, this article also provides a review of ENVI-met simulation results that were reported in the reviewed papers. It was observed that the majority of the research was conducted on a limited spatial scale and focused on temperature and human thermal comfort.

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>

A thematic review of recent urban overheating impacts research in Asia and its applications to climate resilience

2020 ◽  
Author(s):  
Manon Kohler ◽  
Winston T.L. Chow
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Spatial Organization ◽  
Developmental Change ◽  
Global Climate ◽  
Mitigation Strategies ◽  
Systematic Research ◽  
Climate Change Research ◽  
Climate Resilience ◽  
Urban Heat

<p>Urban areas will be subjected to temperature increases from a combination of global-scale climate change and local-scale urban heat island drivers. The resultant combined heat risk – urban overheating – will notably challenge cities in securing the resilience of public health to combined urban overheating. Although global climate change research is ubiquitous, the urban climate and biometeorological research literature of this century reveals a lag of (sub-) tropical Asian regional studies behind Europe and North America. Through a systematic research review of international urban-scale climate and biometeorological literature from 2000-2019, we propose to reflect the state of the art of the urban overheating issue in Asia alongside its penetration in the regional climate resilience discourses.</p><p>The review reveals (i.) a rise of the number of urban overheating studies throughout in the region in conjunction with rapid demographic and developmental change, except for the central Asia region; (ii.) a “metropolitisation” of the urban heat and biometeorological knowledge, meaning a spatial organization of the knowledge reinforcing the leading position of the Asian national and regional primate cities; (iii.) distinct themes of more research into: large focus on remote-sensed urban heat mapping of Chinese and Indian urban clusters, evaluation of heat mitigation strategies from modeling experiments in nations having economies in transition, compared to more focus on urban-wide heat mortality epidemiological studies in countries already facing aging issues.</p><p>Considering the lack of global climate change considerations in urban overheating and biometeorological studies, the review appeals for a more systematic vision of the urban heat issues where urban overheating consequences (i.e. thermal discomfort, heat morbidity, and mortality) are analyzed and discussed conjunctly with the geographical background of the cities, its urban fabric properties, and its socio-demographic dynamics.</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 Investigating the Relationship between Human Activity and the Urban Heat Island Effect in Melbourne and Four Other International Cities Impacted by COVID-19

2021 ◽  
Vol 14 (1) ◽  
pp. 378
Author(s):  
Cheuk Yin Wai ◽  
Nitin Muttil ◽  
Muhammad Atiq Ur Rehman Tariq ◽  
Prudvireddy Paresi ◽  
Raphael Chukwuka Nnachi ◽  
...  
Keyword(s):  
Climate Change ◽  
Urban Heat Island ◽  
Human Activity ◽  
Global Climate ◽  
Ghg Emissions ◽  
Daily Maximum ◽  
Heat Island ◽  
Urban Resilience ◽  
Urban Heat ◽  
The Relationship

Climate change is one of the biggest challenges of our times, even before the onset of the Coronavirus (COVID-19) pandemic. One of the main contributors to climate change is greenhouse gas (GHG) emissions, which are mostly caused by human activities such as the burning of fossil fuels. As the lockdown due to the pandemic has minimised human activity in major cities, GHG emissions have been reduced. This, in turn, is expected to lead to a reduction in the urban heat island (UHI) effect in the cities. The aim of this paper is to understand the relationship between human activity and the UHI intensity and to provide recommendations towards developing a sustainable approach to minimise the UHI effect and improve urban resilience. In this study, historical records of the monthly mean of daily maximum surface air temperatures collected from official weather stations in Melbourne, New York City, Tokyo, Dublin, and Oslo were used to estimate the UHI intensity in these cities. The results showed that factors such as global climate and geographic features could dominate the overall temperature. However, a direct relationship between COVID-19 lockdown timelines and the UHI intensity was observed, which suggests that a reduction in human activity can diminish the UHI intensity. As lockdowns due to COVID-19 are only temporary events, this study also provides recommendations to urban planners towards long-term measures to mitigate the UHI effect, which can be implemented when human activity returns to normal.

Human thermal comfort in Local climate zones of Berlin

2020 ◽  
Author(s):  
Ines Langer ◽  
Alexander Pasternack ◽  
Uwe Ulbrich
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Heat Island ◽  
Climate Zones ◽  
Local Climate ◽  
Human Thermal Comfort ◽  
Local Climate Zones ◽  
Urban Heat ◽  
The City

<p>Urban areas show higher nocturnal temperature comparing to rural areas, which is denoted by urban heat island. This effect can intensify the impact of global warming in urban areas especially during heat waves, that leads to higher energy demand for cooling the building and higher thermal stress for residents.  </p><p>The aim of this study is to identify the Urban Heat Island (UHI) effect during the heat spell 2018 and 2019 in order to calculated human thermal comfort for Berlin. Berlin, the capital city of Germany covers an area of 892km<sup>2</sup> and its population is growing, therefore more residential areas will be planned in future through higher building. The methodology of this research is to divide Berlin into Local Climate Zones (LCZ's) regarding the concept of Stewart & Oke (2012). Then to evaluate the accuracy of this concept using 30 microclimate stations. Estimating the magnitude of urban heat island and its seasonal changes in combination with human thermal perception in different LCZ during summer time is another objective of this research. </p><p>Ten LCZ's for Berlin were selected, as class 1 (compact high rise), class 3 (compact low rise), class 7 (lightweight low-rise), class C (bush, scrub), class E (bare rock or paved) and class F (bare soil or sand) don't exist in Berlin. Class A (dense trees) is with a fraction of 18.6% in a good agreement with the percentage of dense trees reported from the city administration of Berlin (18.4%), class G (water) has a coverage of 5.1% through our classification instead of 6.7% reported by the city administration. In summary, the LCZ 1-10 cover 59.3% (more than half) of the city area.</p><p>Regarding temperature measurements, which represent a hot summer day with calm wind and clear sky the difference of Local Climate Zones will be calculated and the temperature variability in every LCZ's regarding sky view factor values show the hot spot of the city.</p><p>The vulnerability of LCZ's to heat stress will be ranked and discussed regarding ventilation and other factors.</p><p> </p><p>Literature</p><p>Matzarakis, A. Mayer, H., Iziomon, M. (1999) Applications of a universal thermal index: Physiological equivalent temperature: Intern. J. of Biomet 43 (2), 76-84.</p><p>Stewart, I.D., Oke, T.R. (2012) Local climate zones for urban temperature studies. Bull. Amer. Meteor. Soc. 93 1879-1900. DOI: 10.1175/BAMS-D-11-00019.1.</p><p> </p>

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