Climate report: Denver’s “heat island" could get hotter and harder for homeless

By Robert Davis

The main problem driving “heat islands” – urban areas that experience higher temperatures than neighboring areas – is tall buildings. Other factors include poor urban geometry, density, and building construction.

Photo: Jakob Rosen/Unsplash

A new report by the Intergovernmental Panel on Climate Change (IPCC) suggests that Denver’s urban “heat island” could get hotter, making summers harder to survive for many people experiencing homelessness.  

According to the report, the main problem driving “heat islands” – urban areas that experience higher temperatures than neighboring areas – is tall buildings. Other factors include poor urban geometry, density, and building construction.

Meanwhile, several of Denver’s city plans call for additional building height. Some examples include the East Area Plan, 38th & Blake Area Plan, and the Golden Triangle Plan – all of which call for multi-story mixed-use developments of affordable housing alongside increased multimodal transportation options. 

Rick Cole, executive director of the Congress for New Urbanism, said in a statement that several cities are currently building upward to address local housing affordability issues. However, this approach can create as many problems as it solves if tall buildings are built carelessly, Cole argues. 

“U.S. cities are much more equipped to tackle housing problems and the climate crisis, but action requires political willpower and individual sacrifices,” Cole added. 

People experiencing homelessness face several exposure-related dangers during the summer, including dehydration, sun poisoning, and heat exhaustion. Experts warn that increasing heat island temperatures could make any one of these illnesses potentially lethal. 

At the same time, many homeless people have or develop underlying health conditions such as high blood pressure or heart disease which can be exacerbated by “extreme heat” conditions – defined by the Environmental Protection Agency as a two-or-more-day span of temperatures at or exceeding 90 degrees.   

According to the Metro Denver Homeless Initiative’s 2020 Point in Time Count Dashboard, more than 1,770 individuals experiencing homelessness in metro Denver reported having a chronic health condition. Two-thirds of those individuals are in Denver County, of which 910 are also chronically homeless. 

In June, Climate Central released a report showing Denver is, on average, five degrees hotter than neighboring Littleton, Lakewood, and Aurora. However, the report uses a city-wide average to make its comparisons, meaning certain areas with tall buildings such as Five Points, the Golden Triangle, and the downtown core could be even hotter. 

A spokesperson for Denver Health told Denver VOICE that paramedics in the city do treat people experiencing homelessness for exposure-related illnesses, but the organization cannot determine how many or at what frequency because first responders often do not ask for a patient’s housing status. 

Over the summer, Denver opened 10 “cooling stations” at recreation centers that provide ice, water, and rest areas for people to seek refuge from the heat. Street outreach teams have also been deployed to help homeless people access cooling stations as well. However, this is only a stopgap measure. 

Laura Swartz, communications director for Community Planning and Development, told Denver VOICE in an emailed statement that the combination of Denver’s climate action programs “accelerated a citywide conversation about the role of Denver's built environment at combating climate change.”

Denver is currently working on several ways to reduce the heat island effect by making its homes more climate-friendly. For example, the City adopted its Green Building Ordinance in 2018 which requires all buildings over 25,000 sq. ft. to build a “cool roof” – a specialized roof made of materials that reflect more sunlight than they absorb. These buildings must also provide green space and on-site solar panels or any other renewable energy devices. 

Instead of providing green space, building owners can pay a fee of $50 per sq. ft. of roof space into the Green Building Fund. This fund supports Denver’s efforts to acquire more green space, improve its water quality, and create urban forests, among other green initiatives. 

However, these requirements do not apply to one-and-two-family residences, buildings up to three stories tall, temporary structures, air-supported structures, and greenhouses. 

Denver also wants to reduce greenhouse gas (GHG) emissions from its existing buildings and homes with a plan to make all existing buildings and residences to achieve net-zero energy by 2030. The City estimates that 64% of its total GHG emissions come from its existing structures. 

To this end, Denver adopted its Benchmarking ordinance in 2019 which requires all buildings to report their energy performance to the Office of Climate Action, Sustainability & Resiliency. Some other initiatives include creating incentive programs for residents to switch from steam and natural gas utilities to electric power. 

While these policies slowly chip away at Denver’s heat island effect, the city is seeing more days of extreme heat per year, according to a report by the Colorado Health Institute (CHI). In 2020, Denver County recorded 61 days of temperatures at 90 degrees or higher, a nearly 33% increase from 2017. 

At this current pace, the Rocky Mountain Climate Organization estimates that Denver will see at least seven more days of extreme heat per year by 2040.

Karam Ahmad, a policy analyst at CHI, described these events as a “unique opportunity” for the city. 

“Extreme heat is only one of many factors that significantly put this population’s health at risk,” Ahmad said in a statement, “but the combined forces of a growing number of people experiencing homelessness and rising temperatures may create a window of opportunity to not only protect some of the most vulnerable from extreme heat but also reimagine how we address homelessness in Colorado.”