Climate change is impacting urban areas especially hard, and densely populated cities are suffering the most.
The urban heat island effect means that city temperatures can be several degrees higher than nearby rural regions. That’s because materials like concrete and asphalt absorb and radiate heat. Vehicles and air-conditioning units expel heat, and towering buildings block wind flow.
Officials across the globe are trying to cool cities down. In Chicago, which has a history of fatal heatwaves, more than 500 rooftops have been covered with vegetation, which releases cooling water vapor and acts as natural insulation for the building. Los Angeles, which has a vast network of freeways, has painted some of its roads with a solar-reflective material.
But detailed information about urban temperatures is scarce. That became clear to entrepreneur Jay Sadiq soon after he founded a startup in Abu Dhabi to modify asphalt to absorb less heat, when a potential client encouraged him to identify the hottest parts of the city, where the material would be most beneficial.
Sadiq couldn’t find the level of granular data he needed, so he started working on harnessing the information himself. Today, his company FortyGuard is focused on leveraging data and artificial intelligence (AI) technology to provide a detailed view of urban temperature dynamics.
He hopes that it will enable urban planners, chief heat officers, businesses, and real estate developers to make data-driven decisions, and residents to better plan their lives.
Difficult data collection
Extreme heat can cause heat-related illnesses and death, particularly for vulnerable groups like young children and the elderly. Global heat-related mortality for people aged 65 and older increased approximately 85% between 2017 and 2021.
As billions of people move to urban areas in the coming decades, between half and three-quarters of the global population could be exposed to life-threatening extreme heat and humidity by 2100, according the UN’s Intergovernmental Panel on Climate Change.
Rising temperatures also makes it harder to sleep at night, and difficult to be productive during the day, especially for outdoor workers.
Although urban heat is gaining more attention, most weather stations haven’t been built to specifically address the issue, and they’re often located at an airport or atop a hillside – areas that aren’t representative of the temperature on a city sidewalk.
“Historically, most meteorological agencies would be tasked with monitoring the weather at scales larger than cities,” says James Voogt, a professor in the department of Geography and Environment at the University of Western Ontario, who is an expert in urban climatology.
Satellites that measure surface temperature can cover wide areas but can’t provide detailed information about neighborhood hotspots. And trees and tall buildings can block satellites from recording temperatures at ground level. “It doesn’t see the shade underneath,” says Voogt.
Some cities have started collecting information using sensors mounted on streetlights or buses, and others, including Hong Kong, have deployed dense urban meteorological networks. “But not many cities have such a dense measurement network,” says Chao Ren, an associate professor of architecture at the University of Hong Kong, who specializes in applied climatology and climate design.
Urban heat tech
FortyGuard, which today has 16 employees and offices in Abu Dhabi and San Jose, California, collects 32 billion data points daily from third-party providers, but Sadiq says he can’t reveal much about their sources, given market competition.
It then uses AI to produce models that take into account variables that impact how temperature is felt – including a city’s elevation, vegetation, water bodies, and atmospheric conditions, such as cloud cover, to give a fuller view of local temperature dynamics, he says. “Our approach goes beyond measuring air temperature at a specific point in time,” Sadiq adds.
Some of the company’s most robust information is about certain US cities, allowing it to model urban temperature for each 10 square meters, with 89% accuracy, according to Sadiq.
FortyGuard offers advisory services, and it has worked with clients like Masdar City, an experimental “sustainable city” in the United Arab Emirates, to help it pinpoint heat hotspots to add trees and water features.
But the startup, which is “about to about to close a large funding round,” is aiming to position itself as a technology company, says Sadiq. He hopes to integrate its technology into existing platforms, like a real estate or map platform. That could enable homebuyers to figure out the least hot neighborhood in a city, or runners to determine the best route for a morning run, he says.
Technology platforms are already incorporating climate-related information from other providers. In late September, US real estate website Zillow announced that its listings would feature information such as wildfire risk, air quality and heat.
Others are applying AI to urban heat issues. In September, Google announced a new Heat Resilience tool, which applies AI to aerial and satellite images to help cities deal with extreme heat.
Voogt and Ren said that it’s difficult to comment on FortyGuard’s urban heat intelligence without knowing more about its data sources, validation methods and technology. “The key element is how such AI is being trained and on what,” says Voogt.
But there is “definitely a need and demand for high spatial resolution temperatures in urban environments,” he adds.
Ren said what’s most important about urban heat information is how it will be used. While interest in urban heat is increasing, some places are doing better than others at addressing it, by educating residents about the issue, creating warning systems, or incorporating mitigation considerations into building codes or city planning.
“The question is really, who will be the end user of your data, and who will put such urban heat information into their practices?” she says.
