The following is a draft review of extreme heat research as it applies to physical planning and design, as mentioned in this post. If you know of other papers that should be included or if you have comments or ideas, please let me know – praxislandarch (at) gmail (dot) com – or through the Comments section below.
Research Needs for Extreme Heat and Physical Planning/Design
An increase in the frequency of extreme heat events is one of the primary effects of climate change. Meehl and Tebaldi (2004) are widely cited for their prediction of “more intense, more frequent, and longer lasting” 21st century heat waves. Spatial planning and design knowledge can be brought to bear on the problem of extreme heat, as human comfort in outdoor environments has historically been a concern. Expanding this area of planning and design research can contribute to the goal of community adaptation and resilience. Heat-related mortality and morbidity have also been a past concern for residents in urban environments, but temperature increases brought on by climate change, especially in locations where the population is unaccustomed to high temperatures, make this topic even more significant today.
Bioclimatic design is a type of urban design aimed at increasing human thermal comfort. There is a substantial body of literature on urban heat island (UHI), as documented by a review by Arnfield (2003). Modeling of UHI is a common theme, and much of the modeling has been conducted at the scale of an entire city. Some modeling efforts have addressed spatial variability within cities (Stone and Norman, 2006), and physical characteristics that influence variability (Kolokotroni and Giridharan, 2008; Golany, 1996).
Extreme heat is a leading weather-related cause of mortality and morbidity, and there have been many studies of this relationship (e.g., Kalkstein and Greene, 1997). Studies of the relationship between urban form and spatial distribution of vulnerable urban populations (Harlan et al., 2006; Johnson et al., 2009) are growing in number, and proposals have been made regarding ways to mitigate the human health impacts of extreme heat (O’Neill et al., 2009).
Recent research published by Vanos et al. (2010) relates extreme heat events to the physical structure of green space in cities and active living (built environment and physical activity). The importance of parks for mitigating UHI has been explored by Chang et al. (2007), and the authors call for more research into this issue. Noteworthy work by Wilhelmi and Hayden (2010) begins to build a theoretical framework.
Considerable research has been conducted in arid climates, but there is a need for more research focused on cities in humid temperate and humid subtropical regions. Some of the highest death rates during heat waves in the United States have occurred in cities like Chicago and Philadelphia, and it is hypothesized that the higher death rates are due to the fact that the population is less acclimated to higher temperatures (Kalkstein and Davis, 1997).
There is a need for additional urban planning/design research in the following areas: urban spatial variability as it relates to extreme heat, extreme heat in humid climates, climate mitigation and adaptation at the neighborhood and site scales, adaptation responses by individuals, urban planning policies to facilitate adaptation, and adaptive design.
Arnfield, J.A. (2003). Two decades of urban climate research: A review of turbulence, exchanges of energy and water, and the Urban Heat Island. International Journal of Climatology 23 (1), 1-26.
Chang, C., Li, M. & Chang, S. (2007). A preliminary study on the local cool-island intensity of Taipei city parks. Landscape and Urban Planning 80, 386-395.
Golany, G.S. (1996). Urban design morphology and thermal performance. Atmospheric Environment 30 (3), 455-465.
Harlan, S.L., Brazel, A.J., Prashad, L., Stefanov, W.L., and Larsen, L. (2006). Neighborhood microclimates and vulnerability to heat stress. Social Science & Medicine 63, 2847-2863.
Johnson, D.P., Wilson, J.S., & Luber, G.C. (2009). Socioeconomic indicators of heat-related health risk supplemented with remotely sensed data. International Journal of Health Geographics 8, 57.
Kalkstein, L.S. & Greene, J.S. (1997). An evaluation of climate/mortality relationships in large US cities and the possible impacts of a climate change. Environmental Health Perspectives 105, 84-93.
Kolokotroni, M. & Giridharan, R. (2008). Urban heat island intensity in London: An investigation of the impact of physical characteristics on changes in outdoor air temperature during summer. Solar Energy 82, 986-998.
Leonhardt, D. (2010). Overcome by heat and inertia. New York Times, July 20th edition. Retrieved from http://www.nytimes.com/2010/07/21/business/economy/21leonhardt.html
Meehl, G.A. & Tebaldi, C. (2004). More intense, more frequent, and longer lasting heat waves in the 21st century. Science 305, 994-997.
National Oceanic and Atmospheric Administration. (2010). State of the climate global analysis June 2010. Washington, DC: National Climatic Data Center. Retrieved from http://www.ncdc.noaa.gov/sotc/?report=global&year=2010&month=6&submitted=Get+Report
O’Neill, M.S., Carter, R., Kish, J.K., Gronlund, C.J., White-Newsome, J.L., Manarolla, X., Zanobetti, A. & Schwartz, J.D. (2009). Preventing heat-related morbidity and mortality: New approaches in a changing climate. Maturitas 64, 98-103.
Stone, B. and Norman, J.M. (2006). Land use planning and surface heat island formation: A parcel-based radiation flux approach. Atmospheric Environment 40, 3561-3573.
Vanos, J.K., Warland, J.S., Gillespie, T.J. & Kenny, N.A. (2010). Review of the physiology of human thermal comfort while exercising in urban landscapes and implications for bioclimatic design. International Journal of Biometeorology 54, 319-334.
Wilhelmi, O.V. & Hayden, M.H. (2010). Connecting people and place: A new framework for reducing urban vulnerability to extreme heat. Environmental Research Letters 5, 1-7.