Climate change’s impact on urban life is on everyone’s minds these days. Are real estate developers choosing the most sustainable materials and energy-efficient technology? Will their projects withstand rising sea levels?
Although wildfires, hurricanes, and floods garner headlines, extreme heat is responsible for more deaths than all other climate-driven disasters in the U.S. combined, according to the Centers for Disease Control . This year, North America experienced the hottest June and July on record with temperatures 2.77°F above average. Worldwide, the combined land and ocean surface temperature in July was 62.07°, the hottest period since such data started being recorded more than 140 years ago.
In April, Miami-Dade County decided to take a proactive approach to rising temperatures: It named Jane Gilbert the world’s first chief heat officer, whose purpose is to “expand, accelerate, and coordinate our efforts to protect people from heat and save lives,” Mayor Daniella Levine Cava said in a statement at the time. Previously, as Miami’s first chief resilience officer, Gilbert helped carve out strategies to address natural disasters and climate change issues like sea-level rise. “When we would go into communities and talk with residents about climate change, heat came up a lot,” Gilbert told Architectural Digest .
Miami’s hurricane season runs from June to November, so rising temperatures and extreme weather go hand in hand in the city, Gilbert said. That’s especially true when a storm causes large-scale outages and leaves many unable to cool their homes. After Hurricane Irma knocked out power in Hollywood, Florida, 12 nursing home deaths were linked to extreme heat . Without electricity, the temperature inside soared to 99°, almost 20° higher than allowed by federal regulations. “In order to reduce the increasing risk of heat to health and livelihoods, you’ve got to look across agencies,” Gilbert said. “What are the different things we are doing and what could be improved?”
Densely populated cities like Miami form heat “islands,” where an inadequate tree canopy and the widespread use of non-porous surfaces like asphalt, concrete, and brick make it harder for neighborhoods to cool down at night. “We have areas that feel 10° hotter,” because of the urban heat island effect, Gilbert said. “And the places most affected are often in the most economically disadvantaged parts of the city.” Lower-income residents may not be able to afford air-conditioning, or they might live in buildings with crumbling power infrastructure.
“Extreme heat does not impact people equally,” Cava said when announcing Gilbert’s appointment. “Poorer communities and Black and Hispanic people bear the brunt of the public health impacts.”
One solution Gilbert is passionate about is developing “climate resilience hubs,” where people can go if it’s too hot. “It’s a trusted place in a community where people can come to cool off, charge their phone, get services, and maybe have preparedness training and learn about energy efficiency,” she said. “These are like emergency shelters, but less ‘shelter-like’ and more focused on heat emergencies, not hurricanes.” Miami already has cooling centers in parks and libraries, but they don’t always have backup power if there’s widespread power loss. With just one hub currently designated, opening more “is our first priority,” Gilbert said.
Another priority is adding to the tree canopy, which can mitigate urban heat islands, she said. The county gives away thousands of trees every year, but increased development and the losses from Hurricane Irma have resulted in a net-zero change. “The goal is to get to 30%,” Gilbert said. It’s been stuck at 20% since 2016. “Particularly in Miami, the challenge is it’s always been hot and to some extent, people are used to it,” Gilbert said. “But we have 300,000 outdoor workers who can’t just stay inside and who are suffering from chronic illnesses.” With so much commercial and residential growth in Miami now, Gilbert says it’s imperative architects and developers factor heat mitigation into their designs. “Passive cooling, passive temperature control, efficient HVAC systems—those are baseline,” she said. “We need to look at backup energy sources—solar power with battery backup. That’s not always an easy thing to push, though, because it can be expensive.” Gilbert wants to see projects that incorporate trees, green roofs, green walls, and more. “We need to look at cool pavements—we may need to update the cool-roof ordinance and require bikeways, walkways, and parking lots to be more reflective and possibly more permeable,” she said.
Miami architect Kobi Karp has long incorporated resilience into his firm’s DNA, including sustainability and heat mitigation. In Fort Lauderdale, Karp—whose first degree was in environmental design—buried the parking lot at the under-construction Four Seasons Hotel and Residences to allow for more landscaping and tree canopy. (A third of the property will be devoted to green space.)
Karp describes the Legacy Hotel & Residences he’s designed for the 27-acre Miami Worldcenter as “a crystalline box that lets lights and air in, but offers blockage from the sun.” He told Architecture Digest , “When you plant trees 20, 30 feet high, you create a shadow-box effect.”
Following Miami’s lead, Athens and Freetown, Sierra Leone , have also established chief heat officers, all in partnership with the Atlantic Council’s Adrienne Arsht-Rockefeller Foundation .
In September, Phoenix appointed its own heat czar: David Hondula, director of the city’s new publicly funded Office of Heat Response and Mitigation. Phoenix experienced its hottest summer on record last year, with more than 114 days where the thermometer tipped past 100°. This year, at least 113 deaths in Maricopa County have been attributed to high temperatures , more than double reported in 2020.
“Addressing the public health and environmental challenges posed by extreme heat is a key priority, and a central component of our city’s efforts to address climate change,” Phoenix Mayor Kate Gallego said in September. Hondula’s office “will work across departments and with external partners to build the vision of a cooler, more sustainable Phoenix and to develop and implement the tangible actions it will take to achieve it,” she added. An environmental scientist and heat researcher at Arizona State University, Hondula has similar goals as Gilbert, including increasing the city’s tree canopy. But like Miami, Phoenix has fallen somewhat short, according to AZ Central : Though it has a goal of shading 25% of the city by 2030, it’s been stalled at about 13% since 2010.
Hondula, who started work October 4, told the site his first priority was to hire “a tree and shade administrator,” and then look at cooling buildings and infrastructure. And, like Gilbert, Hondula is keenly aware that the impact of extreme heat is more pronounced in the neediest areas. Of the 113 heat-related deaths this year, 50 took place indoors, AZ Central reported, including 35 in places lacking functioning air-conditioning. Hondula is determined to make sure resources go where they can do the most good. “The responsibility awaiting the new office, especially its leader, is weighty and humbling,” he said in an October 1 statement . “For some residents, the decisions and actions taken by this office will literally be a matter of life or death.”