If the city of Denver is planting extra trees in your neighborhood, you might live in the worst of the metro area’s sun-blasted heat islands.
A new map from the meteorology data-crunchers at Climate Central shows some of Denver’s most paved-over neighborhoods suffering recent (and looming) heat waves at rates 9 degrees hotter than shaded blocks just a couple of miles away.
The door-to-door pavement and concrete-covered canyons downtown, on South Santa Fe and west of the Mousetrap absorb Denver’s 100-degree sunshine all day and can’t let go of the heat before the next high noon, said adaptation manager Lis Cohen in the city’s office of Climate Action, Sustainability and Resiliency.
“The problem with urban heat islands is that we aren’t totally prepared for several days of extreme heat in a row. Historically, we haven’t seen this before,” Cohen said. Denver was forecast to hit 100 on multiple days over the weekend before a brief respite this week, then return to temperatures in the mid-90s next week.
Underlining official concern about the frequency of spiking heat events, a group of attorneys general from heat-vulnerable states on Tuesday joined a growing petition asking the Federal Emergency Management Agency to add extreme heat as a qualifying natural disaster. The change could open up federal funding for local efforts such as creating more public cooling centers, adding cooling or air filtration to more schools, water distribution and health screenings.
The proposal, backed by Colorado Attorney General Phil Weiser, would “enhance the capacity of our jurisdictions to mitigate the impacts of extreme heat and wildfire smoke before they occur — and to respond as effectively as possible to them when they do happen,” the group said.
Some of the most heat-challenged neighborhoods in Denver are also described by state and federal environment officials as disproportionately impacted communities, those that have suffered more than area averages from historic air pollution or other environmental health hazards. Many of the hottest urban islands on the Climate Central map are relatively low income and have higher percentages of minority residents.
Previous Denver Health studies have shown the neighborhoods to suffer from higher rates of asthma, heart conditions and other ailments exacerbated by environmental conditions such as high heat or air pollution.
Cohen said Denver is also concerned about elderly residents in older homes on treeless lots in the middle of cooler neighborhoods, who might not have money for air conditioning or energy efficient renovations. She also worries about outdoor workers assigned to jobs in heat islands, including Denver’s own transportation and infrastructure employees laying hot asphalt that boosts ambient temperatures close to 200 degrees.
The climate office controls about $40 million in spending each year from a climate-related sales tax boost Denver voters approved in 2020. The money has gone toward electric bike rebates, assistance to businesses and homes electrifying their heating and cooling, and other projects.
After consulting with residents at community forums, the climate office is now working to accelerate a handful of programs aimed at urban heat islands, Cohen said:
- Targeted tree planting, now up to 1,374 new trees in north and west Denver neighborhoods with thin shade canopies. Some of the trees are paid for with a federal grant that includes community nonprofits going door to door and asking shadeless neighbors if they want a tree.
- Assistance for purchasing and installing heat pumps or traditional air conditioning at income-qualified homes or in homes where people with underlying health conditions live. Mapping from data trackers like Climate Central, Cohen said, can reinforce the priorities set by the Denver climate office.
- Distribution of air purifiers to some homes, whether separate from or paired with air cooling equipment. Air purifiers can remove dust and particulates from wildfires or other irritants.
Residents and nonprofit organizations that want more input with the city on how to combat heat islands or take on other summer heat issues, Cohen said, should join the Community Heat Summit on July 26.