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August 23, 2019

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How do we plan and design for Las Vegas’ rapidly warming climate?

Heat rising

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Similar to many U.S. cities built after the invention of cars, Las Vegas hasn’t historically been designed in a sustainable way, which has contributed to the region’s warming.

Temperatures have risen in almost every city in the United States since 1970, but no metropolitan area is heating up as quickly as Las Vegas.

That’s according to a report released in April by Climate Central, a nonprofit news organization that researches and reports on climate change.

Las Vegas experienced a temperature increase of 5.76 degrees Fahrenheit from 1970 to 2018, a seemingly staggering statistic considering that average temperatures here are already relatively high. No other city came close to Vegas’ rate of warming, the report found; the second most rapidly warming city, El Paso, Texas, has warmed by 4.74 degrees since 1970.

Unfortunately, similar to many U.S. cities built after the invention of cars, Las Vegas hasn’t historically been designed in a sustainable way, which has contributed to the region’s warming, says Ted Greenhalgh, an environmental studies professor at UNLV. Greenhalgh noted that as the Valley’s population has increased, growth has mostly shifted development outward, rather than into the region’s inner core.

That urban sprawl has created a need for more paved roads. Along with cars releasing climate change-causing greenhouse gas emissions, asphalt roads absorb heat and create the urban heat island effect, whereby urbanized areas are hotter than less-developed places with natural landscaping. Buildings themselves, especially those that haven’t been planned with energy efficiency and sustainability in mind, also contribute to this effect.

“As we continue to have our sprawl here in the Valley ... the temperatures in Las Vegas are going to continue to go up,” Greenhalgh said.

In short, the dominance of cars, the region’s well-known propensity for sprawl, and climate change-influenced temperature increases across the Southwest are creating a trifecta of warming in the Las Vegas Valley. To keep the region as cool as possible, officials need to rethink the planning strategies—or lack thereof—that have shaped Southern Nevada since its explosive transformation in the 1940s and 1950s.

“Las Vegas is warming up faster than any other [U.S.] city, so we have to do more,” said Steffen Lehmann, director of the School of Architecture at UNLV and co-director of the school’s Urban Futures Lab. “We have to do better in how to mitigate and adapt to climate change and be more resilient.”

Planning in the age of global warming

Greenhalgh, whose latest research focuses on how communities can mitigate and adapt to climate change, says that despite being the most rapidly warming metropolitan area, Las Vegas does have some factors working to its advantage when it comes to climate change.

The first is that it already has a hot, dry climate. Extreme heat kills every year in Southern Nevada, and the Southern Nevada Health District reported a spike in heat-related deaths in 2017. But some additional warming isn’t going to affect the average Las Vegan, Greenhalgh said.

“As a desert, we’re supposed to be hot. We’re already in the upper range of where heat should be,” he explained.

Additionally, while some U.S. cities and states are finding that certain crops can no longer grow as reliably or efficiently as average temperatures rise, Southern Nevada’s climate has never been conducive to water-intensive agriculture, Greenhalgh said. The region also isn’t projected to see a noticeable increase in extreme, intense storms, another common manifestation of climate change elsewhere in the U.S.

Finally, because precipitation alone hasn’t been sufficient to support Las Vegas’ population for decades, the Valley has long been on the forefront of water conservation, Greenhalgh said. Planners and officials have also pushed solar energy for years, although we could harness the power of the sun here even more.

That leaves rising temperatures as the primary concern for Las Vegas in the age of climate change, something Greenhalgh and Lehmann said can be offset by smart planning techniques. Planting native trees and plants throughout public spaces and using lighter-colored pavement are two known strategies for combatting urban heat and cooling down public spaces.

“We need native trees. We need to bring them back. We cut them all down,” Lehmann said.

From a broader perspective, rather than building “out,” municipal and county officials need to encourage greater density in existing urban and suburban parts of the Valley.

“We cannot afford one-story buildings anymore,” Lehmann said. “In the past, maybe one family lived on a site. Now the same site [might] have four families.”

Increasing the region’s housing density alone, however, won’t be enough to discourage driving, Lehmann said, because grocery stores, employment centers and more are still quite spread out. That’s why Lehmann advocates the creation of mixed-use “hubs” where people could work, play and live, reducing the need to drive long distances. Such hubs should be compact enough so that within each of them, people can get around on foot, bike or bus, something he said is unrealistic for the average Las Vegan now in the sprawling metropolitan area.

“In Las Vegas, the distances are so huge,” he said. “You can’t tell people to cycle, to go by bicycle or to walk, and of course public transport is so poor, and the buses are infrequent.”

Tools to cool public and private space

Just as the region could implement zoning and planning strategies in anticipation of higher average temperatures, so too could officials and builders look at specific architectural tools to cool down outdoor and indoor spaces. Most of these tools would also reduce carbon emissions and the overall environmental impacts of development.

Dwayne Eshenbaugh, principal at Novus Architecture and president of Las Vegas’ chapter of the American Institute of Architects, said architects and builders have a host of techniques at their disposal to address the effects of climate change.

Some are simple and fundamental, such as constructing homes and buildings at a favorable orientation to the sun, so as not to absorb excessive sunlight. Other techniques are more advanced; for example, new software innovations allow architects to design protected openings such as windows away from direct solar gain.

“The software that’s been developed absolutely gives us the ability to design smarter and to protect space,” Eshenbaugh said.

Building materials make a difference, too. Certain shades of glass and roof materials can reflect, rather than absorb, sunlight, Eshenbaugh explained. Buildings can also be designed not to produce carbon emissions, or even to generate energy. Especially in a hot desert climate, builders should make use of green roofs or garden roofs, a natural way to cool down interior temperatures, Lehmann added.

Given the abundance of planning and architectural tools available, the main barrier to climate-ready planning is a lack of will from planners, politicians and the public, Eshenbaugh and Lehmann suggested.

“There’s another side to [this] coin, and that’s the side of the consumer, who doesn’t really care,” Eshenbaugh said.

Most consumers are more concerned about the aesthetics of their homes and neighborhoods than whether they are designed efficiently for the warming desert climate. And developers looking to maximize profits from large subdivisions don’t always build with sustainability and climate resiliency in mind, especially if the public isn’t asking for it.

But Eshenbaugh is hopeful that if manufacturers, architects, developers and planners commit to sustainable practices, preparing for a warmer Las Vegas-—and a warmer world—that could become the norm.

To a certain extent, it’s already happening. AIA, the largest organization of architects in the U.S. with 90,000-plus members, is adapting a resolution this month on climate change, Eshenbaugh said.

The resolution declares an “urgent climate imperative for carbon reduction,” calls on architects to “achieve a zero carbon, equitable, resilient and healthy built environment,” and pledges that architects will enlist support from “peers, clients, policymakers and the public at large.”

While Eshenbaugh suggested that producers are the ones who can influence climate planning, Lehmann noted that consumers in Las Vegas would also gain from climate-friendly planning in anticipation of a warmer region. After all, increasing walkability, transit access and green space have proven beneficial to local economies, as well as to people’s health and well-being.

Nonetheless, redesigning a region built around cars and single-family homes would be no small task.

“You can do this, but you’d have to be smart about how you make those plans. You’d have to really do a deep dive on the planning side,” Greenhalgh said.

This story originally appeared in the Las Vegas Weekly.