What is Phoenix's Tree and Shade Master Plan?

It’s survival of the fittest in the neighborhoods surrounding downtown Phoenix. Trees that offer an oasis of shade are few and far between. The residents of these neighborhoods are used to sun rays radiating heat off the roads and sidewalks.

Phoenix only has enough trees to shade roughly 10% of the city according to the City of Phoenix. This percentage is less than half of the 25% shade coverage goal the city aims to reach by 2030.

The Tree and Shade Master Plan was finalized in 2010. The plan's main goal is for 25% of Phoenix to be shaded by 2030. However, less than seven years away from the end date and the shade canopy is no more than it was in 2010, roughly 12%. Though Phoenix may not be as close to its goal as it hoped there are still substantial benefits if the goal is reached by 2030. Urban forestry, the management of trees in an urban area, can help make Phoenix not only a cooler but more sustainable city. Increased urban forestry can help the city reduce its carbon footprint, energy costs, and water runoff and can overall provide more clean air according to Adaptation Clearinghouse, an organization focusing on impacts from climate change.

While the current shade canopy progress is halted at 12% Phoenix has recently received a grant for $10 million to help with the shade canopy and urban reforestation. New programs such as Canopy for Kids and the Community Canopy Grant Program allow residents to apply for a tree and a supply kit. These programs are meant to promote the planting of trees in census-tract areas with low-income residents or in schools with students of low-income families.

Kayla Killoren, the tree equity project manager for the city said the programs are designed to provide residents with trees rather than the money to buy one. Killoren said this format would be less prohibitive to many people applying for the grant program and would ideally increase shade coverage.

“We’re thinking this might be one of the biggest investments in the City of Phoenix in terms of Community Canopy and planting trees within communities. We think this is going to be very transformational,” Killoren said.

Though increased shade can benefit the whole city the benefits are much starker for low-income neighborhoods that tend to have less shade coverage, such as those eligible for the Community Canopy program. When submitting a recommendation for the Master Plan the Environmental Quality and Sustainability Commission added a focus on neighborhoods with low-income populations or those vulnerable to extreme heat.

The City of Phoenix partnered with the Arizona State University School of Sustainability to inform residents of the benefits of urban tree planting. According to the graphic the team put together, healthy trees can increase property values by up to 10% and areas that are heavily vegetated can be 9 degrees cooler than those less vegetated. The benefits of urban forestry are clear. The work it takes to make the 25% goal achievable is more convoluted.

Phoenix hasn’t directly spoken about the progress on the shade canopy. However, the Tree and Shade Subcommittee asked to establish a permanent position to oversee the Urban Forest and the Master Plan’s progress. The subcommittee said its motivation was the current status of shade coverage and the need for departmental supervision.

According to the proposition by the subcommittee, “Tree canopy in the City of Phoenix must double to achieve the original goals established in the Tree and Shade Master Plan.”

The subcommittee further explained many different City departments are responsible for work within the Tree and Shade Master Plan. The subcommittee wrote, “Coordination and efficiencies across those units have been difficult to realize.”

In addition to asking for the addition of a managerial position, to ensure the shade canopy goal is achieved, the Tree and Shade Subcommittee members denoted that “trees in the Urban Forest that have died or been removed shall be replaced one-for-one each year.” The recommendation to the plan also included asking for additional funding to be allotted to the plan.

“The Council shall allocate sufficient funding to increase the Urban Forest annually by at least 10% of the 2030 Urban Forest Goal and to cover the increased costs of the care and maintenance of trees on City owned and managed lands,” the recommendation by the subcommittee stated.

Urban heat islands are areas of higher temperatures compared to nearby and surrounding areas. City infrastructure such as roads, sidewalks, buildings and more retain the heat from the sun rather than reflecting it into the atmosphere. Temperatures are often much higher in places with little vegetation due to this heat island effect, according to the US Environmental Protection Agency.

Phoenix is hot but there are specific neighborhoods such as South Mountain, Maryvale and other neighborhoods surrounding the Sky Harbor Airport that are specifically urban heat islands. According to a Vox video piece on Phoenix, low-income areas of Phoenix tend to have higher surface temperatures and higher heat-related deaths compared to the wealthier areas of the city. These neighborhoods have a high population of low-income residents and very few green spaces. Little green space usually means little shade coverage and more exposed concrete which traps the sun's heat.

Eva Olivas the executive director and the Affordable Housing Disposition Program compliance monitor at the Phoenix Revilitization Corp. described her organization’s Urban Heat Leadership Academy. The academy is aimed to inform people on a grassroots level of the consequences of severe heat. Olivas said many people in the neighborhoods most affected do not have a full understanding of climate change.

“They do not recognize the impact of climate change and heat in particular on their everyday life, they just go to that survival mode, day-to-day existence,” Olivas said.

By 2030, if Phoenix meets the Tree and Shade Master Plan there would be a significant decrease in the amount of heat-related illnesses due to the increase in shade coverage. In 2022, roughly 75% of emergency room visits were due to a heat-related illness. Again in 2022, there were 671 heat-related deaths in Arizona according to the Arizona Department of Health Services.

By increasing the shade canopy in Phoenix and lowering surface temperatures in low-income communities, heat-related health issues may be decreased due to the temperature decrease. According to the study “The Relationship Between Trees and Human Health: Evidence from the Spread of the Emerald Ash Borer,” there seems to be a correlation between the loss of trees and the increase in cardiovascular and respiratory illnesses.

The study explains cities infested with the emerald ash borer saw an increase in mortality rates as tree populations decreased due to the infestation. Though the emerald ash borer is not prevalent in Phoenix, the study shows a decrease in trees can lead to a higher risk of mortality.

Another study focused on the specific climate of neighborhoods in Phoenix and the residents' tolerance for heat-related stress and discomfort. The study “Neighborhood microclimates and vulnerability to heat stress” found there was a statistically significant temperature difference between neighborhoods of different socioeconomic standings. The study showed that lower-income residents and minority groups were more likely to live in neighborhoods with higher temperatures.

“High settlement density, sparse vegetation, and having no open space in the neighborhood were significantly correlated with higher temperatures,” the study reported.

With help from surrounding communities, organizations and the city itself the Tree and Shade Master Plan will lower temperatures and decrease health risks to those most vulnerable.