Study links urbanization, future heat-related mortality

May 30, 2014

Rising temperatures and urban growth could mean more deaths and hospital visits in Maricopa County

Phoenix stands at a parched crossroads. Global scale climate change is forecast to bring hotter summers and more extreme heat to the Valley, but regional urbanization also will impact temperatures experienced by residents. Phoenix skyline at night Download Full Image

So how should Phoenix grow knowing that such growth could cause temperatures to increase in the future and bring added health risks? Should the city deploy mitigating technologies to help fight summer’s heat? Would adopting a low-growth strategy reduce the adverse health consequences of hot weather?

New Arizona State University research examines the heat-health aspects resulting from urbanization and the challenge of sustainable future growth in Maricopa County. A study released this week shows how urban development could be a factor in the number of lives lost due to heat in future summers. The study is described in the article “Challenges associated with projecting urbanization-induced heat-related mortality,” published in the current online issue of the journal Science of the Total Environment.

“Extreme heat is the leading weather-related killer in the United States,” said David Hondula, a postdoctoral scholar in health informatics in ASU’s Center for Policy Informatics and lead author of the study. “In Maricopa County, we see more than 100 premature deaths and hundreds of excess emergency department visits as a result of high temperatures each summer. Understanding how different urban development strategies will impact the health risks associated with heat can help long-term planners and public officials make more informed decisions that lead to sustainable and healthy cities.”

In the research, the team tried to quantify the number of excess deaths attributed to heat in Maricopa County based on three future urbanization and adaptation scenarios and multiple exposure variables. Two scenarios (low and high growth projections) represent the maximum possible uncertainty range associated with urbanization in central Arizona; a third represents an adaptation strategy by simulating the deployment of white roof technology to the area.

The researchers – who, in addition to Hondula, included Matei Georgescu and Robert C. Balling Jr., both of ASU’s School of Geographical Sciences and Urban Planning – related temperature to mortality using historical data from 1983-2007. Regional climate model simulations based on 2050-projected urbanization scenarios for Maricopa County generated distributions of temperature change, and from these changes, future excess heat-related mortality was estimated. They studied Maricopa County because it is a fast growing metropolitan area situated in a semi-arid region that experiences “chronic” heat during the summer months.

Overall, projections of heat-related mortality ranged from a decrease of 46 deaths per year (-95 percent) to an increase of 339 deaths per year (+359 percent). Projections based on minimum temperature showed the greatest increase for all expansion and adaptation scenarios, and were substantially higher than those for daily mean temperature. Projections based on maximum temperature were largely associated with declining mortality. Low growth and adaptation scenarios led to the smallest increase in predicted heat-related mortality based on mean temperature projections.

Because of the environment in which it is built, increases in overnight minimum temperatures in Maricopa County associated with urbanization were found to be of much greater concern for health impacts compared to increases in daytime maximum temperatures. The same would be true in many other cities located in semi-arid regions.

“Future urbanization will lead to slightly lower summer daytime maximum temperatures in the urban core of Maricopa County compared to the surrounding natural landscape because of the high heat-retaining capacity of the built environment,” Matei Georgescu said. “Continued growth would enhance this effect in the future, leading to further declines in daytime highs and associated declines in health risks. The tradeoff is that nighttime temperatures increase significantly with urbanization, and this nighttime warming is much greater than the expected daytime cooling.”

Hondula added that what this means for planners is that because heat impacts vary from day to night, projections of heat-related health outcomes that do not consider place-based, time varying urban heat island effects are “neglecting essential elements for policy relevant decision-making.”

“The manner in which the Sun Corridor develops over the next several decades will impact the regional climate and, if no new adaptation measures are introduced, change the health risks for Maricopa County residents associated with extreme heat,” Hondula said. “The greatest health concern comes from large expected increases in nighttime temperatures, which could be mitigated by lower-growth scenarios.

“The next step is to look more closely at the conditions people experience on hot days, to ultimately determine if high maximum temperatures, minimum temperatures or some combination of the two is the real culprit leading to adverse health events,” he added.

Associate Director, Media Relations & Strategic Communications


Winners announced in collaborative, global sci-fi competition

May 31, 2014

Arizona State University's Center for Science and the Imagination, Intel and the Society for Science & the Public are proud to announce the winners of their competition, "The Future – Powered by Fiction." The competition, which ran from May through December 2013, challenged young people ages 13-25 from all over the world to share their visions for possible futures inspired by real science and technology. "The Future – Powered by Fiction" was truly global in scope: the 274 total submissions include stories from 15 different countries and 36 U.S. states.

The competition is part of Tomorrow Project USA, an ongoing collaboration among the Center for Science and the Imagination, Intel and the Society for Science & the Public, that uses competitions and other tools to drive critical, creative, fact-based conversations about possible futures. Tomorrow Project USA logo Download Full Image

The winners were originally announced by Intel futurist Brian David Johnson on a live Google Hangout from the Intel International Science and Engineering Fair in Los Angeles on May 14.

“In an increasingly complex world, we need to arm students with new tools for synthesizing enormous amounts of information,” says Ed Finn, director of the Center for Science and the Imagination and assistant professor in ASU's School of Arts, Media and Engineering and the Department of English. “Storytelling is a powerful method for taking information from a variety of sources, imbuing it with human significance and making meaning from it. The Tomorrow Project [provides the] opportunity for students to use storytelling to explore the future as a spectrum of possibilities and consider the potential consequences of the rapid and accelerating changes we’re seeing in science and technology.”

Ten winners were selected to receive a $1,000 prize from the Intel Foundation and to have their work published in an anthology, "The Future – Powered by Fiction," to be released in summer 2014. The winners represent three different countries and eight U.S. states:

• Michael Arteaga, Toronto, Canada, “The Last Allocation”
• Diya Basrai, California, U.S., “Descent”
• Carlos Duralde, Georgia, U.S., “Lost Dreams”
• Aliah Eberting, Utah, U.S., “A Flavorful Future”
• Christine Ann Hurd, Texas, U.S., “And the Tapestry of Starts Curled Up To Reveal the Face of God”
• Alycia McCreary, Kentucky, U.S., “Parenthood Planned”
• Natalie Petit, Ohio, U.S., “A Toothache for the Truth”
• Hannah Reese, North Carolina, U.S., “Family Feast”
• Claire Spackman, Hong Kong, “The Genes of Tomorrow”
• Jorge Tenorio, Arizona, U.S., “LifeTime”

Tenorio is an ASU graduate student and a research analyst at ASU’s Office of University Initiatives.

In addition to the ten $1,000 prizewinners, 33 additional stories will be published in a series of three anthologies to be released throughout 2014 and 2015. To see the full list of winners, visit:

The winners were selected by an editorial board of scholars, journalists, artists and futurists, chaired by Ed Finn and G. Pascal Zachary, professor of practice at ASU's Walter Cronkite School of Journalism and Mass Communication and the Consortium for Science, Policy and Outcomes.

Bryan Walsh, senior writer for TIME magazine and a member of the editorial board, said of the winning entries: “The stories I was fortunate enough to judge showed a wonderful imaginative sense, an ability to use fiction to explore the shape of our future.”

All of the anthologies published in 2014 and 2015 will be free to download and share from the Center for Science and the Imagination and Tomorrow Project USA.

Joey Eschrich

program manager, Center for Science and the Imagination