John Locher / AP
Wednesday, Oct. 16, 2019 | 2 a.m.
Not all islands make for exciting weekend getaways.
Urban heat islands — paved areas in cities with higher temperatures than nearby rural or plant-filled areas — are becoming more and more prevalent worldwide as climate change and urbanization intensify.
The trend is especially concerning for Southern Nevada, as an August report from the nonprofit research organization Urban Land Institute found that nowhere in the United States is the urban heat island effect more intense than in Las Vegas.
Municipal officials, local developers and urban planning experts considered the problems caused by urban heat islands in the region as well as policies and design approaches that could combat the phenomenon during a panel discussion Tuesday in downtown Las Vegas.
Moderated by Nevada Public Radio producer Doug Puppel, the panel featured Urban Land Institute researcher Elizabeth Foster, Southern Nevada Water Authority general manager John Entsminger, UNLV School of Architecture director Steffen Lehmann, Las Vegas’ chief sustainability officer Tom Perrigo, and Tom Warden, senior vice president of the Howard Hughes Corp.
Extreme heat is the deadliest climate-related killer nationwide, Foster said in opening the discussion. In Las Vegas, where average temperatures have risen by 5.8 degrees Fahrenheit since 1970, heat-related deaths have also been on the rise.
Various urban design strategies have the potential to worsen urban heat islands, while some could provide solutions to extreme heat, Foster said. There is no magic bullet when it comes to cooling down urban areas in Southern Nevada, but the region could borrow elements proven to work elsewhere.
For example, the Las Vegas area could introduce more vegetation to public spaces, increase urban density, diversify land-use types within neighborhoods, and retrofit buildings to be more sustainable, said Lehmann, a longtime proponent of sustainable design. All of those changes would help cool down public spaces and lessen urban sprawl, a major driver of the urban heat island effect, Lehmann said.
“(This) could be disruptive and it will be significant what we have to change, but here we are, and this is a good start,” Lehmann said.
Although Southern Nevada has made strides in water conservation and sustainability, local leaders acknowledged room for improvement and described how they plan to make urban areas heat-resilient.
Summerlin is in the process of replacing water-thirsty landscaping and decorative panels with drought-friendly plants, Warden said. Howard Hughes, developer of the northwest master-planned community, has also established goals for planting more trees in public spaces and hopes to build denser, mixed-use neighborhoods in its 22,500 remaining undeveloped acres.
Las Vegas is crafting a new master plan that will serve as the city’s blueprint from now until 2050, Perrigo said. In developing the plan, city officials are thinking about ways that underutilized or abandoned urban strips could be repurposed into compact, urban centers. They also hope to better prioritize planting trees in public places and reduce car use through smart planning, Perrigo said.
“We built the city with way too much right-of-way for cars,” he said. “We’re taking it back and giving it to people and trees and plants.”
Nonetheless, assuming average temperatures continue to increase due to climate change, challenges lie ahead for the Las Vegas area.
In the coming years, water levels in our primary water source, Lake Mead, are expected to decline in part because of climate change. The water authority has also already spent close to $2 billion over the last two years adapting to a warmer Lake Mead, and those costs will only go up, Entsminger said.
“At the utility scale, our operations are impacted in almost every facet by warmer temperatures today as well as making plans for what we’re going to need to adapt to over the next 30, 40 years,” he said.
While increasing green spaces and incorporating plants into urban areas lessen the urban heat island effect, landscaping in Las Vegas still uses more water than any other sources. Entsminger therefore encourages planners to be cognizant of whether their plants are desert-friendly and to recognize that even some commonplace desert plants, such as Afghan pines, could be wiped out in the future climate.
“We think there’s a lot of tree canopy that exists in Las Vegas today that probably isn’t going to survive these warmer temperatures,” Entsminger said.
Reducing the urban heat island effect will require participation from a broad range of stakeholders, including casino owners on the Las Vegas Strip, Lehmann said. Clark County, whose jurisdiction includes most of the Strip, was not represented on the panel.
Some Strip properties have shown a commitment to sustainability, but that doesn’t change the fact that they consume a lot of energy, food and water through air conditioning, lighting and other uses, Lehmann said.
“Mandalay Bay has been leading. They created a huge array of solar panels on the roof and that’s very good, but we need to see more of that,” he said.
Perhaps Las Vegas’ rapid growth, while seemingly a driver of sprawl, could actually help the region become an incubator of ideas and innovation when it comes to climate and heat-resilient planning, Lehmann said.
“We should be known as the city that has the best practices to combat urban heat,” he said.