scholarly journals Impact of climate change on outdoor thermal comfort in cities in united states

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.

2014 ◽  
Vol 2 (2) ◽  
pp. 25-36 ◽  
Author(s):  
Modeste Kameni Nematchoua ◽  
Gholamreza Roshan ◽  
René Tchinda ◽  
◽  
◽  
...  

2021 ◽  
Author(s):  
Sara Top ◽  
Dragan Milošević ◽  
Steven Caluwaerts ◽  
Stevan Savić

<p>Both heat and cold waves cause extreme human thermal discomfort and a clear excess in mortality. This shows the importance of knowing the prevailing thermal comfort conditions and how thermal comfort conditions vary in various environments so measures can be taken. Microclimatic and outdoor human thermal comfort conditions are investigated in various built-up and green areas in the city of Ghent (Belgium) using meteorological measurements of six weather stations of the MOCCA (Monitoring the Cities Climate and Atmosphere) network in combination with calculations done by RayMan.</p><p>Normal to extreme summer heat wave periods show that dangerous strong heat stress prevails during the daytime periods at all locations. Comparison of thermal comfort during normal and extreme summer heat wave periods showed that heat stress is more extreme when a heat wave is more intense. Overall the urban park in Ghent was the most comfortable location during heat waves since it effectively mitigates heat stress in the city. These results should be taken into account in urban planning and design to keep mid-latitude cities livable.</p><p>Further, a one year data series revealed that outdoor cold stress was more apparent during 2017 in the mid-latitude city of Ghent that experiences a mild maritime climate. During spring and summer, both heat stress and cold stress occurred due to the larger diurnal temperature range compared to the other seasons. Even though high Physiological Equivalent Temperatures (PET) were obtained during a heat wave in summer, heat stress did not occur as intensely and as frequently compared to cold stress on annual level. It could thus be stated that outdoors, cold stress is a bigger threat than heat stress. However, one should keep in mind that the study was executed for outdoor thermal heat comfort and that people will take shelter or take measures when feeling uncomfortable. The question is thus rather, how are citizens protected against heat and cold stress? Currently, the Belgian society is better adapted to cold stress since most buildings contain central heating, while air conditioning is not standard. Future projections predict an increase in temperature, causing more occurrence of extreme heat stress, while extreme cold stress will be reduced. Additionally, the urban heat island effect currently has mainly a positive effect on the average annual outdoor thermal comfort conditions, while it will become a negative effect in the warmer future. Measures should thus be taken to reduce the threat of future heat stress.</p>


2011 ◽  
Vol 104 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Xiang Li ◽  
Taro Takahashi ◽  
Nobuhiro Suzuki ◽  
Harry M. Kaiser

Author(s):  
Anne M. K. Stoner ◽  
Jo Sias Daniel ◽  
Jennifer M. Jacobs ◽  
Katharine Hayhoe ◽  
Ian Scott-Fleming

Flexible pavement design requires considering a variety of factors including the materials used, variations in water tables, traffic levels, and the climatic conditions the road will experience over its lifetime. Most pavement designs are based on historical climate variables such as temperature and precipitation that are already changing across much of the United States, and do not reflect projected trends. As pavements are typically designed to last 20 years or more, designs that do not account for current and future trends can result in reduced performance. However, incorporating climate projections into pavement design is not a trivial exercise. Significant mismatches in both spatial and temporal scale challenge the integration of the latest global climate model simulations into pavement models. This study provides a national-level overview of what the impact of climate change to flexible pavement could look like, and where regional focus should be placed. It also demonstrates a new approach to developing high-resolution spatial and temporal projections that generates hourly information at the scale of individual weather stations, and applies this as input to the AASHTOWare Pavement ME Design™ model. The impact of three different future climates on pavement performance and time to reach failure thresholds in 24 locations across the United States are quantified. Changes to projected pavement performance differ by location, but nearly all result in decreased performance under current design standards. The largest increases in distress are observed for permanent deformation measures, especially toward the end of the century under greater increases in temperature.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4730
Author(s):  
Mohamed Elhadi Matallah ◽  
Waqas Ahmed Mahar ◽  
Mushk Bughio ◽  
Djamel Alkama ◽  
Atef Ahriz ◽  
...  

Climate change and expected weather patterns in the long-term threaten the livelihood inside oases settlements in arid lands, particularly under the recurring heat waves during the harsh months. This paper investigates the impact of climate change on the outdoor thermal comfort within a multifamily housing neighborhood that is considered the most common residential archetype in Algerian Sahara, under extreme weather conditions in the summer season, in the long-term. It focuses on assessing the outdoor thermal comfort in the long-term, based on the Perceived Temperature index (PT), using simulation software ENVI-met and calculation model RayMan. Three different stations in situ were conducted and combined with TMY weather datasets for 2020 and the IPCC future projections: A1B, A2, B1 for 2050, and 2080. The results are performed from two different perspectives: to investigate how heat stress evolution undergoes climate change from 2020 till 2080; and for the development of a mathematical algorithm to predict the outdoor thermal comfort values in short-term, medium-term and long-term durations. The results indicate a gradual increase in PT index values, starting from 2020 and progressively elevated to 2080 during the summer season, which refers to an extreme thermal heat-stress level with differences in PT index averages between 2020 and 2050 (+5.9 °C), and 2080 (+7.7 °C), meaning no comfortable thermal stress zone expected during 2080. This study gives urban climate researchers, architects, designers and urban planners several insights into predicted climate circumstances and their impacts on outdoor thermal comfort for the long-term under extreme weather conditions, in order to take preventive measures for the cities’ planning in the arid regions.


Sign in / Sign up

Export Citation Format

Share Document