Southern Nevada needs half a million trees to reach ‘tree equity’

Nevada saw record high temperatures in July as part of a historic heat wave across the west, and a new study reveals how unevenly protective tree shade is distributed in Nevada’s cities, and how tree inequity disadvantages communities of color and the poor.

The study by American Forests examined 3,810 municipalities, including 150,000 neighborhoods in 486 cities with at least 50,000 residents across the country and found that Black, brown and low-income neighborhoods have significantly fewer trees than wealthier, whiter communities, even in the same cities.

Dubbed the Tree Equity Score, the metric measures  neighborhoods using several factors: population density, neighborhood income, average surface temperatures, existing tree canopy, racial demographic makeup, employment and various health statistics. 

Neighborhoods with a majority of people of color have 33% less tree canopy on average than majority white communities, according to the study.  And neighborhoods with 90% or more of their residents living in poverty have 41% less tree canopy than communities with only 10% or less of the population in poverty.

In Southern Nevada, more than 560,000 trees will need to be planted to reach “tree equity,” or the number of trees needed so that all residents can benefit from shade, cooler temperatures and reductions in carbon. 

For example, trees shade 1% of the surface area of Sunrise Manor near North Lamb Boulevard and East Lake Mead Boulevard in North Las Vegas, an area with a poverty rate of 71% and where 82% of the population is people of color. Average surface temperature in the area reaches 108 degrees. Meanwhile, in part of Summerlin known as The Hills South, where the poverty rate is 7% and people of color only account for 17% of the population, trees shade 18% of surface area, which helps lower the average surface temperature to 101 degrees.

“Wealthy neighborhoods have more trees. Data across the country bears that out,” said Chris David, vice president of GIS and mapping at American Forests.

The City of North Las Vegas, a majority minority city where about 39% of the population is Hispanic and nearly 20% is Black, has the least tree coverage in the Las Vegas metro area. City officials say the lack of trees in the city is due to previous design standards and requirements, adding that newer neighborhoods in the city have landscaping requirements on par with other development underway in the valley.

“In 2020, North Las Vegas led the region in new home sales, and along with those growing developments, new parks and green spaces are coming online,” said Patrick Walker, a spokesman for the City of North Las Vegas.

In the Reno-Sparks area, more than 42,000 trees would need to be planted to achieve Tree Equity in all neighborhoods.

Disparities in tree coverage are present throughout Reno, too. 

In one neighborhood near the crossing of Sun Valley Boulevard and Dandini Boulevard, where 59% of the population is people of color and the poverty rate is 56%, trees only shade 4% of the surface area. By contrast, in a wealthier, whiter neighborhood in West Reno near California Avenue and Hunter Lake Drive, the poverty rate is 12%, people of color only account for 12% of the population, and trees shade 30% of the surface area, which helps lower the average surface temperature to three degrees less than the neighborhood with fewer trees. 

Building up tree equity is a “moral imperative” said Jad Daley, president and chief executive officer of American Forests. 

“This country is denying life and death infrastructure to people based on income and race. That’s morally insupportable. This is just completely at odds with our values as a country,” Daley said.

More trees wouldn’t just mean more shade. Those 560,000 trees could also help protect Southern Nevada from about 58 million gallons of stormwater runoff, reducing the danger of flash floods. The additional trees would also provide significant health benefits by capturing more than 6,500 tons of carbon and 2.1 tons of PM 2.5 – a particulate linked to numerous ailments, and that has also been connected to increases in Covid-19 cases in Nevada.

“In cities we’re fighting offense and defense,” David said. “Trees will always be the best way to pull carbon out of the air” contributing to broader climate goals.  “But they also provide adaptation, like shade, so people can walk to work in the extreme heat.”

“When talking about public health we have to think about where people live. Our study area includes where more than 70% of the population lives,” David said.

Since trees play a vital role in keeping neighborhoods cooler during heat season, urbanized areas are likely to have some neighborhoods with higher temperatures than others, with deadly consequences.

Scientists from the Desert Research Institute found that heat-related deaths in Clark County have significantly increased over the last few years, in large part due to the rise in extreme heat and the resulting “urban heat island effect,” where heat-absorbing materials like asphalt maintain high temperatures.

Las Vegas showed significant increases in annual extreme heat waves, from an average of 3.3 events per year from 2007-2009 to 4.7 per year in the 2010-2016 period. The findings match recent historic trends, which show a steady increase in severity and frequency of excess heat waves in Las Vegas since 1980. And as heat wave intensity increases, so does the number of heat-related deaths. Trees are a cost effective way to mitigate those effects for Nevada residents, said David.

“You might just walk under a tree and it’s ten degrees cooler,” David said. “The urban heat island effect is only going to exacerbate climate change.  Our last defense against that,” he said, “are trees.”