Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research reveals the give and take of urban temperature mitigating technologies

10.02.2014
Life in a warming world is going to require human ingenuity to adapt to the new realities of Earth.

Greenhouse-gas induced warming and megapolitan expansion are both significant drivers of our warming planet. Researchers are now assessing adaptation technologies that could help us acclimate to these changing realities.


The deployment of cool roofs, roofs typically painted white, help mitigate summertime temperatures but in Florida and some Southwestern cities like Phoenix (pictured) the roofs also have a negative effect on rainfall.

Credit: Ken Fagan, Arizona State University

But how well these adaptation technologies – such as cool roofs, green roofs and hybrids of the two – perform year round and how this performance varies with place remains uncertain.

Now a team of researchers, led by Matei Georgescu, an Arizona State University assistant professor in the School of Geographical Sciences and Urban Planning and a senior sustainability scientist in the Global Institute of Sustainability, have begun exploring the relative effectiveness of some of the most common adaptation technologies aimed at reducing warming from urban expansion.

The work showed that end-of-century urban expansion within the U.S. alone and separate from greenhouse-gas induced climate change, can raise near surface temperatures by up to 3 C (nearly 6 F) for some megapolitan areas. Results of the new study indicate the performance of urban adaptation technologies can counteract this increase in temperature, but also varies seasonally and is geographically dependent.

In the paper, "Urban adaptation can roll back warming of emerging megapolitan regions," published in the online Early Edition of the Proceedings of the National Academy of Sciences, Georgescu and Philip Morefield, Britta Bierwagen and Christopher Weaver all of the U.S. Environmental Protection Agency, examined how these technologies fare across different geographies and climates of the U.S.

"This is the first time all of these approaches have been examined across various climates and geographies," said Georgescu. "We looked at each adaptation strategy and their impacts across all seasons, and we quantified consequences that extend to hydrology (rainfall), climate and energy. We found geography matters," he added.

Specifically, what works in California's Central Valley, like cool roofs, does not necessarily provide the same benefits to other regions of the U.S., like Florida, Georgescu said. Assessing consequences that extend beyond near surface temperatures, like rainfall and energy demand, reveals important tradeoffs that are oftentimes unaccounted for.

Cool roofs are a good example. In an effort to reflect incoming solar radiation, and therefore cools buildings and lessen energy demand during summer, painting one's roof white has been proposed as an effective strategy. Cool roofs have been found to be particularly effective for certain areas during summertime.

However, during winter these same urban adaptation strategies when deployed in northerly locations, further cool the environment and consequently require additional heating to maintain comfort levels. This is an important seasonal contrast between cool roofs (i.e. highly reflective) and green roofs (i.e. highly transpiring). While green roofs do not cool the environment as much during summer, they also do not compromise summertime energy savings with additional energy demand during winter.

"The energy savings gained during the summer season, for some regions, is nearly entirely lost during the winter season," Georgescu said.

In Florida, and to a lesser extent Southwestern states of the U.S., there is a very different effect caused by cool roofs.

"In Florida, our simulations indicate a significant reduction in precipitation. The deployment of cool roofs results in a 2 to 4 millimeter per day reduction in rainfall, a considerable amount (nearly 50 percent) that will have implications for water availability, reduced stream flow and negative consequences for ecosystems," he said. "For Florida, cool roofs may not be the optimal way to battle the urban heat island because of these unintended consequences."

Georgescu said the researchers did not intend to rate urban adaptation technologies as much as to shed light on each technology's advantages and disadvantages.

"We simply wanted to get all of the technologies on a level playing field and draw out the issues associated with each one, across place and across time."

Overall, the researchers suggest that judicious planning and design choices should be considered in trying to counteract rising temperatures caused by urban sprawl and greenhouse gasses. They add that, "urban-induced climate change depends on specific geographic factors that must be assessed when choosing optimal approaches, as opposed to one size fits all solutions."

Source:
Matei Georgescu, (480) 727-5986
Media contact:
Skip Derra, (480) 965-4823; skip.derra@asu.edu

Skip Derra | EurekAlert!
Further information:
http://www.asu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

nachricht How to detect water contamination in situ?
22.09.2016 | Tomsk Polytechnic University (TPU)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

 
Latest News

New switch decides between genome repair and death of cells

27.09.2016 | Life Sciences

Nanotechnology for energy materials: Electrodes like leaf veins

27.09.2016 | Physics and Astronomy

‘Missing link’ found in the development of bioelectronic medicines

27.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>