scholarly journals Impact of Climate Change on Outdoor Thermal Comfort and Health in Tropical Wet and Hot Zone (Douala), Cameroon

2014 ◽  
Vol 2 (2) ◽  
pp. 25-36 ◽  
Author(s):  
Modeste Kameni Nematchoua ◽  
Gholamreza Roshan ◽  
René Tchinda ◽  
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2020 ◽  
Vol 158 ◽  
pp. 01002
Author(s):  
Yuqiao Huang ◽  
Dayi Lai ◽  
Yiqing Liu ◽  
Huang Xuan

Since urban open spaces provide various benefits to the citizens, it is necessary to improve the outdoor thermal comfort in urban open spaces. However, global warming increases heat stress and at the same time decrease cold stress of outdoor spaces. The final impact of climate change on outdoor thermal comfort is not evident, and depends on the climate characteristics. This study investigated the influence of climate change on outdoor thermal comfort conditions of five selected cities (Minneapolis, New York City, San Francisco, Miami, and Las Vegas) with distinctive climate patterns in the United States. It is found that all cities suffered from deterioration in thermal comfort. This is because the increases in the heat stress rate were greater than the decreases in cold stress rate. In the 2080s, the greatest reduction in acceptable thermal stress rate happened in Miami from 44.7% to 21.3% under high emission scenario.


2020 ◽  
Author(s):  
Sabrina Erlwein ◽  
Stephan Pauleit

<p>Urban green and blue spaces such as water bodies, parks and street trees reduce outdoor temperatures and energy consumption of buildings through evaporative cooling and shading and are thus promoted as nature based solutions to enhance climate resilience. However, in growing cities, supply of urban green space often conflicts with increasing housing demand, resulting in dense neighbourhoods with lack of green. Therefore, the transdisciplinary project “Future green city” seeks to identify possibilities for balancing population growth and increasing living space demand with the development of nature-based solutions for climate change adaptation. In a transdisciplinary approach with the City of Munich, living labs are used to investigate how nature-based solutions can be integrated into spatial planning processes.</p><p>For the case of an urban redevelopment site with row buildings and a vast amount of greenery, eight densification scenarios were elaborated with city planners to derive planning guidelines for the further development of the area. The scenarios consider the effects of densification with additional floors and new buildings, the use of new building materials and energy efficiency standards, the construction of underground car parks and consequently a loss of green space to varying degrees. We are particularly interested in the interplay of densification and availability of green and its impact on indoor and outdoor thermal comfort, energy efficiency of buildings and their life cycle based emission balance. Microclimate modelling is employed to quantify and evaluate the impacts of densification on outdoor thermal conditions during heat days and the benefits of urban green in reducing heat stress.</p><p>First modelling results show that additional floors have less impact on human thermal comfort than loss of green space caused by the provision of required parking space. Though underground car parking avoids surface soil sealing, it leads to the removal of existing urban green and excludes the planting of large trees. Informal instruments such as mobility concepts can reduce space consumption by car parking. Moreover, urban redevelopment also bears the potential to increase climate resilience of the stock by targeted greening strategies. The potential is greater, the earlier climate change adaptation is considered as a topic in planning processes. Modelling helps to explore strength and weaknesses of different alternatives in early design stages.</p>


2010 ◽  
Vol 31 (2) ◽  
pp. 324-335 ◽  
Author(s):  
Sofia Thorsson ◽  
Fredrik Lindberg ◽  
Jesper Björklund ◽  
Björn Holmer ◽  
David Rayner

2021 ◽  
Vol 13 (6) ◽  
pp. 3051
Author(s):  
Mohamed Elhadi Matallah ◽  
Djamel Alkama ◽  
Jacques Teller ◽  
Atef Ahriz ◽  
Shady Attia

Oases settlements are common entities of human agglomerations throughout desert regions. Oases settlements face several environmental challenges such as climate change, which can render them insufferably hot and unlivable within decades. Therefore, this study aims to assess the outdoor thermal comfort variation within three different oases urban fabrics of Tolga Oases Complex in Algeria. The overarching aim is to quantify thermal comfort and guide landscape, and urban designers improve outdoor thermal comfort. The methodology relies on microclimatic measurements and weather datasets (TMY2, TMY3, TMYx), combining observations and numerical simulations. A total of 648 Physiological Equivalent Temperature (PET) values were calculated in three different urban fabrics in Tolga Oases Complex, Algeria. Between 2003 and 2017, a remarkable microclimatic change was found, causing a high and accelerated heat stress level of 76%. The study results inform architects, urban planners and climatologists about climate change effects and urban sprawl impact on the oases lands. Moreover, urban strategies should seek mitigation and adaptation benefiting from the existing green infrastructure of palm groves.


2021 ◽  
Vol 13 (14) ◽  
pp. 7811
Author(s):  
Ka-Ming Wai ◽  
Lei Xiao ◽  
Tanya Zheng Tan

Adaptation to prepare for adverse climate change impacts in the context of urban heat islands and outdoor thermal comfort (OTC) is receiving growing concern. However, knowledge of quantitative microclimatic conditions within the urban boundary layer in the future is still lacking, such that the introduction of adequate adaptation measures to increase OTC is challenging. To investigate the cooling performance of a water spraying system in a sub-tropical compact and high-rise built environment in summer under the influence of future (2050) climatic conditions, results from two validated models (Weather Research and Forecast (WRF) and ENVI-met models) have been used and analyzed. Our results indicate that the spraying system provides cooling of 2–3 °C for ambient air temperature at the pedestrian-level of the urban canyons considered here, which benefits pedestrians. However, improvement of the OTC in terms of the physiological equivalent temperature (PET—a better indicator of human thermal sensation) was noticeable (e.g., <42 °C or from very hot to hot) when the urban canyon was orientated parallel to the prevailing wind direction only. This implies that in order to improve city resilience in terms of heat stress, more holistic adaptation measures in urban planning are needed. This includes the introduction of more breezeways and building disposition to facilitate the urban ventilation, as well as urban tree arrangement and sunshades to reduce direct solar radiation to plan for the impact of future climate change.


Author(s):  
José A Orosa ◽  
Ángel M Costa ◽  
Ángel Rodríguez-Fernández ◽  
Gholamreza Roshan

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