Dynamic synchronization of extreme heat in complex climate networks in the contiguous United States

Heat waves are the deadliest type of natural hazard among all weather extremes in the United States. Given the observed and anticipated increase in heat risks associated with ongoing climate change, this study examines community vulnerability to extreme heat and the degree to which heat island mitigation (HIM) actions by state/local governments reduce heat-induced fatalities. The analysis uses all heat events that occurred over the 1996–2011 period for all United States counties to model heat vulnerability. Results show that: (1) Higher income reduces extreme heat vulnerability, while poverty intensifies it; (2) living in mobile homes or rental homes heightens susceptibility to extreme heat; (3) increased heat vulnerability due to the growth of the elderly population is predicted to result in a two-fold increase in heat-related fatalities by 2030; and (4) community heat island mitigation measures reduce heat intensities and thus heat-related fatalities. Findings also show that an additional locally implemented measure reduces the annual death rate by 15%. A falsification test rules out the possibility of spurious inference on the life-saving role of heat island mitigation measures. Overall, these findings inform efforts to protect the most vulnerable population subgroups and guide future policies to counteract the growing risk of deadly heat waves.

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Ambient heat and risks of emergency department visits among adults in the United States: time stratified case crossover study

BMJ ◽

10.1136/bmj-2021-065653 ◽

2021 ◽

pp. e065653

Author(s):

Shengzhi Sun ◽

Kate R Weinberger ◽

Amruta Nori-Sarma ◽

Keith R Spangler ◽

Yuantong Sun ◽

...

Keyword(s):

United States ◽

Older Adults ◽

Emergency Department ◽

Health Insurance ◽

Mental Disorders ◽

Confidence Interval ◽

Renal Disease ◽

Extreme Heat ◽

Case Crossover ◽

Ed Visits

Abstract Objective To quantify the association between ambient heat and visits to the emergency department (ED) for any cause and for cause specific conditions in the conterminous United States among adults with health insurance. Design Time stratified case crossover analyses with distributed lag non-linear models. Setting US nationwide administrative healthcare claims database. Participants All commercial and Medicare Advantage beneficiaries (74.2 million) aged 18 years and older between May and September 2010 to 2019. Main outcome measures Daily rates of ED visits for any cause, heat related illness, renal disease, cardiovascular disease, respiratory disease, and mental disorders based on discharge diagnosis codes. Results 21 996 670 ED visits were recorded among adults with health insurance living in 2939 US counties. Days of extreme heat—defined as the 95th centile of the local warm season (May through September) temperature distribution (at 34.4°C v 14.9°C national average level)—were associated with a 7.8% (95% confidence interval 7.3% to 8.2%) excess relative risk of ED visits for any cause, 66.3% (60.2% to 72.7%) for heat related illness, 30.4% (23.4% to 37.8%) for renal disease, and 7.9% (5.2% to 10.7%) for mental disorders. Days of extreme heat were associated with an excess absolute risk of ED visits for heat related illness of 24.3 (95% confidence interval 22.9 to 25.7) per 100 000 people at risk per day. Heat was not associated with a higher risk of ED visits for cardiovascular or respiratory diseases. Associations were more pronounced among men and in counties in the north east of the US or with a continental climate. Conclusions Among both younger and older adults, days of extreme heat are associated with a higher risk of ED visits for any cause, heat related illness, renal disease, and mental disorders. These results suggest that the adverse health effects of extreme heat are not limited to older adults and carry important implications for the health of adults across the age spectrum.

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Why and How Do Cities Plan for Extreme Heat?

Journal of Planning Education and Research ◽

10.1177/0739456x211053654 ◽

2021 ◽

pp. 0739456X2110536

Author(s):

C. J. Gabbe ◽

Gregory Pierce ◽

Emily Petermann ◽

Ally Marecek

Keyword(s):

United States ◽

The United States ◽

Extreme Heat ◽

Adaptation Planning ◽

Hispanic Population ◽

Large Cities ◽

Heat Adaptation ◽

Specific Policy ◽

Leadership Support ◽

Tree Canopies

Heat is the deadliest weather-related hazard in the United States. This paper studies municipal heat adaptation using survey and planning data from California. We first analyze the characteristics of municipalities that innovate. Cities with heat-related policies have greater degrees of projected extreme heat, leadership support, environmental justice planning, and smaller Hispanic population shares. We then assess specific policy innovations of six large cities by plan type. Some strategies, including expanding tree canopies, have been widely adopted while others, such as cool walls, are rarely included. Findings suggest that planners can—and should—play a central role in heat adaptation planning.

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Heat Waves and Innovation in Air Conditioning in the United States

Weather Climate and Society ◽

10.1175/wcas-d-21-0095.1 ◽

2021 ◽

Keyword(s):

United States ◽

Air Conditioning ◽

Heat Waves ◽

Heat Exposure ◽

The United States ◽

Extreme Heat ◽

Weather Data ◽

County Level ◽

Similar Increase ◽

Patent Data

AbstractThis study investigates whether extreme heat episodes (heatwaves) have contributed to the development of air conditioning technology in the United States. To this end we use weather data to identify days at which heat and relative humidity were above levels comfortable to the human body, and match these with patent data at the county level for nearly a hundred years. We find that in the two years after a county has experienced extreme heat air-conditioning patents increase. Overall, average extreme heat exposure results in an increase of 7.5% greater innovation. We find no similar increase in the frequency of non-air conditioning related patent filings, and therefore conclude that heatwaves result in innovation targeting their mitigation.

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Refined assessment of urban residents' exposure to extreme temperatures across the United States

10.5194/egusphere-egu2020-86 ◽

2020 ◽

Author(s):

Jiachuan Yang ◽

Leiqiu Hu

Keyword(s):

United States ◽

Population Dynamics ◽

Heat Waves ◽

The United States ◽

Extreme Weather ◽

Extreme Heat ◽

Cold Wave ◽

Urban Residents ◽

Extreme Temperatures ◽

Spatiotemporal Population Dynamics

Extreme temperatures during heat and cold waves are severe health hazards for humans. Residents&#8217; exposure controls the susceptibility of the urban population to these hazards, yet the spatiotemporal population dynamics has been long overlooked in assessing the risk. In this study, we conducted comparative analysis over 16 major urban habitats under three massive heat waves and one cold wave across the contiguous United States. Incorporating WRF weather simulations with commute-adjusted population profiles, we found that the interaction between population dynamics and urban heat islands makes residents exposed to higher temperatures under extreme weather. After accounting for diurnal population movement, urban residents&#8217; exposure to heat waves is intensified by 2.0 &#177; 0.8 oC (mean &#177; standard deviation among cities), and their exposure to cold wave is attenuated by 0.4 &#177; 0.8 oC. The aggravated exposure to extreme heat is more than half of the heat wave hazard (temperature anomaly 3.7 &#177; 1.5 oC). The underestimated exposure to extreme heat needs to be taken into serious consideration, especially in nighttime given the evident trend of observed nocturnal warming. Results suggest that the major driver for modified exposure to heat waves is the spatial temperature variability, i.e., residents&#8217; exposure is more likely to be underestimated in a spread-out city. The current release of warnings for hazardous extreme weather is usually at the weather forecast zone level, and our analysis demonstrates that such service can be improved through considering spatiotemporal population dynamics. The essential role of population dynamics should also be emphasized in temperature-related climate adaptation strategies for effective and successful interventions.

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