Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Exposure of US population to extreme heat could quadruple by mid-century

19.05.2015

Interaction of warming climate with a growing, shifting population could subject more people to sweltering conditions

U.S. residents' exposure to extreme heat could increase four- to six-fold by mid-century, due to both a warming climate and a population that's growing especially fast in the hottest regions of the country, according to new research.


This graphic illustrates the expected increase in average annual person-days of exposure to extreme heat for each US Census Division when comparing the period 1971-2000 to the period 2041-2070. Person-days are calculated by multiplying the number of days when the temperature is expected to hit at least 95 degrees by the number of people who are projected to live in the areas where extreme heat is occurring. The scale is in billions.

Credit: ©UCAR.

The study, by researchers at the National Center for Atmospheric Research (NCAR) and the City University of New York (CUNY), highlights the importance of considering societal changes when trying to determine future climate impacts.

"Both population change and climate change matter," said NCAR scientist Brian O'Neill, one of the study's co-authors. "If you want to know how heat waves will affect health in the future, you have to consider both."

Extreme heat kills more people in the United States than any other weather-related event, and scientists generally expect the number of deadly heat waves to increase as the climate warms. The new study, published May 18 in the journal Nature Climate Change, finds that the overall exposure of Americans to these future heat waves would be vastly underestimated if the role of population changes were ignored.

The total number of people exposed to extreme heat is expected to increase the most in cities across the country's southern reaches, including Atlanta, Charlotte, Dallas, Houston, Oklahoma City, Phoenix, Tampa, and San Antonio.

The research was funded by the National Science Foundation, which is NCAR's sponsor, and the U.S. Department of Energy.

Climate, population, and how they interact

For the study, the research team used 11 different high-resolution simulations of future temperatures across the United States between 2041 and 2070, assuming no major reductions in greenhouse gas emissions. The simulations were produced with a suite of global and regional climate models as part of the North American Regional Climate Change Assessment Program.

Using a newly developed demographic model, the scientists also studied how the U.S. population is expected to grow and shift regionally during the same time period, assuming current migration trends within the country continue.

Total exposure to extreme heat was calculated in "person-days" by multiplying the number of days when the temperature is expected to hit at least 95 degrees by the number of people who are projected to live in the areas where extreme heat is occurring.

The results are that the average annual exposure to extreme heat in the United States during the study period is expected to be between 10 and 14 billion person-days, compared to an annual average of 2.3 billion person-days between 1971 and 2000.

Of that increase, roughly a third is due solely to the warming climate (the increase in exposure to extreme heat that would be expected even if the population remained unchanged). Another third is due solely to population change (the increase in exposure that would be expected if climate remained unchanged but the population continued to grow and people continued to moved to warmer places). The final third is due to the interaction between the two (the increase in exposure expected because the population is growing fastest in places that are also getting hotter).

"We asked, 'Where are the people moving? Where are the climate hot spots? How do those two things interact?'" said NCAR scientist Linda Mearns, also a study co-author. "When we looked at the country as a whole, we found that each factor had relatively equal effect."

At a regional scale, the picture is different. In some areas of the country, climate change packs a bigger punch than population growth and vice versa.

For example, in the U.S. Mountain region--defined by the Census Bureau as the area stretching from Montana and Idaho south to Arizona and New Mexico--the impact of a growing population significantly outstrips the impact of a warming climate. But the opposite is true in the South Atlantic region, which encompasses the area from West Virginia and Maryland south through Florida.

Exposure vs. vulnerability

Regardless of the relative role that population or climate plays, some increase in total exposure to extreme heat is expected in every region of the continental United States. Even so, the study authors caution that exposure is not necessarily the same thing as vulnerability.

"Our study does not say how vulnerable or not people might be in the future," O'Neill said. "We show that heat exposure will go up, but we don't know how many of the people exposed will or won't have air conditioners or easy access to public health centers, for example."

The authors also hope the study will inspire other researchers to more frequently incorporate social factors, such as population change, into studies of climate change impacts.

"There has been so much written regarding the potential impacts of climate change, particularly as they relate to physical climate extremes," said Bryan Jones, a postdoctoral researcher at the CUNY Institute for Demographic Research and lead author of the study. "However, it is how people experience these extremes that will ultimately shape the broader public perception of climate change."

###

About the article

Title: Future population exposure to U.S. heat extremes

Authors: Bryan Jones, Brian C. O'Neill, Larry McDaniel, Seth McGinnis, Linda O. Mearns, and Claudia Tebaldi

Publication: Nature Climate Change

On the Web

For news releases, images and more: http://www.ucar.edu/atmosnews

The University Corporation for Atmospheric Research (UCAR) manages NCAR under sponsorship by the National Science Foundation. Any opinions, findings, conclusions, or recommendations expressed in this release do not necessarily reflect the views of the National Science Foundation.

Media Contact

Laura Snider
NCAR/UCAR Media Relations
lsnider@ucar.edu
303-497-8605

David Hosansky
NCAR/UCAR Media Relations
hosansky@ucar.edu
303-497-8611

Laura Snider | EurekAlert!

Further reports about: Atmospheric Research CUNY Corporation Nature Climate Change grow heat heat waves waves

More articles from Earth Sciences:

nachricht AWI researchers measure a record concentration of microplastic in arctic sea ice
24.04.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Climate change in a warmer-than-modern world: New findings of Kiel Researchers
24.04.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>