Latest news with #urbanheat
CBS News
9 hours ago
- Climate
- CBS News
How urban planners are working to reduce heat. Thermal imaging shows how hot surfaces get.
With temperatures soaring this week, residents in Cambridge, Massachusetts are doing whatever they can to beat the heat. For many, that means less time outside. "I'm out in this for 10 minutes to walk the dog and then I go home and it's shower time," a Cambridge resident said. Amid the heat wave, public parks with splash pads have been a reprieve for families seeking relief. "I'm here Monday through Friday," said Emily Ortiz, a young woman enjoying the splash pad at Dana Park. As climate change continues to push urban temperatures higher, experts are exploring long-term strategies to make city living more tolerable. Kishore Varanasi is a principal designer at CBT, a firm focused on creating cooler public environments. Using thermal imaging, Varanasi demonstrates just how hot urban surfaces can become. "You can see here the surface is measuring 136 degrees Fahrenheit, but the air temperature is 88 degrees," he said. "So, if I bring it to the shade, you see that it matches the air temperature." Varanasi said that the excessive heat is due to the way cities have been historically designed. "What makes cities hotter is everything that we've built. The air conditioners spitting out heat, the materials that we've used, the asphalt, cars," Varanasi said. "All of it makes cities 10 to 15 degrees hotter." To combat the urban heat island effect, Varanasi and his team are working with urban planners to redesign spaces by introducing more shade and using materials like special concrete mixes that retain less heat. "We also have other alternatives to create shade," he said. For example, you can use structures, like the one at Cambridge Crossing. "It is a part of the park, but it is shaded so on days like this you can be in this space and feel comfortable," he said. It is an effect that can be felt, with temperatures decreasing up to 40 degrees under his shaded structures. As extreme heat becomes more common, Cambridge's push for cooler, shaded spaces may serve as a model for other urban areas grappling with rising temperatures.
CTV News
20-07-2025
- Science
- CTV News
Downtown Montreal is up to six degrees hotter than Mount Royal, study finds
Research led by a Montreal student shows that downtown can be up to six degrees hotter than greener parts of the city. Research led by a Montreal student shows that downtown can be up to six degrees hotter than greener parts of the city — a temperature gap with real consequences for health and equity as climate change intensifies. Johanna Arnet is a master's student at Université du Québec à Montréal (UQAM) and a member of its Chair on Urban Forests. Her research focuses on how spatial and temporal temperature patterns vary within the city, and how urban forests can help mitigate the effects of heat. Using a bicycle with high-precision sensors — including air and surface temperature sensors, a pyranometer to measure solar radiation, and GPS — Arnet has been pedaling through different Montreal neighbourhoods to collect data at human height. 'We're sampling every second, which means we're gathering readings every few metres,' said Arnet, whose project is carried out in collaboration with both UQAM and Concordia University. 'It's very fine scale, and more relevant to human health than satellite imagery, which mostly captures surface temperatures on rooftops.' Arnet said her routes were designed to capture differences in canopy cover and built environment, two major factors influencing local temperatures. One of her new routes, added this summer, goes from downtown Montreal to Mount-Royal Park. 'Along that stretch, we found an average difference of around six degrees, which is quite significant,' she said. Temperatures are recorded between 3 p.m. and 5 p.m., typically the hottest hours of the day in the city. Additional measurements are also taken at night — at least three hours after sunset — when the urban heat island effect tends to peak. Ville-Marie borough looking to make a difference The study is being done in partnership with the Ville-Marie borough and the Quartier des spectacles neighbourhood, both of which are exploring ways to reduce heat through urban greening. 'There's a whole bunch of tree-planting initiatives underway, and they were wondering which areas should be prioritized,' said Arnet. 'This project helps map out the hotter and colder areas in the borough so that decisions can be more targeted.' But cooling dense, downtown areas isn't always simple. In the Quartier des spectacles, Arnet said, the layout changes constantly to accommodate various events such as festivals. Because of this, planting permanent trees isn't always an option. Instead, the neighbourhood has turned to a more flexible solution: mobile greenery. 'They have over 100 trees in pots that can be moved around to work within the changing layout,' said Arnet. 'They even use some of them as road blockers to restrict car access, which is another innovative way to reduce heat without ripping up concrete.' Arnet stressed the importance of mixing strategies — like adding shade structures, green roofs, or green walls — especially in areas where space is limited. The resilience of the city's urban forest is also key, she added, noting the need for species diversity to protect against future pest outbreaks. 'Functional and structural diversity is crucial, trees, shrubs, and ground-level vegetation all play a role,' she said. How heatwaves expose inequality Isabella Richmond is a PhD student in biology at Concordia University researching how urban ecosystems and design can influence heat exposure and health outcomes. 'We define cities by their impervious surfaces, which basically means concrete, and in Montreal that's definitely what comes to mind when you think of downtown,' said Richmond, who is helping with Arnet's project. With fewer trees and more built infrastructure, heat accumulates and radiates through the day and night. Richmond said that a six-degree difference is far from negligible. 'To the human body, that's the difference between comfortable and dangerously hot,' she said. 'Even a half-degree can be felt, so, six degrees is massive.' She pointed to another example: the stark contrast between Park-Extension and the Town of Mount Royal. The two adjacent neighbourhoods show wide differences in canopy cover, housing density, and access to green space — and, as a result, temperature. 'There's a real imbalance in who feels the worst of the heat,' said Richmond. 'Urban design is everything.' The consequences of heat exposure go beyond discomfort. Richmond pointed to studies that have shown links between urban heat and higher risks of cardiovascular and respiratory illness. She noted that wealthier, whiter communities tend to live in cooler areas, a phenomenon she referred to as the 'luxury effect.' 'And the people who live in hotter zones often don't have access to things like air conditioning, either in their homes or even in a vehicle,' she said. 'So not only are they experiencing higher temperatures, but they don't have the same access to relief.' As climate change accelerates, the research team hopes its data will help guide how and where cooling interventions are made and ensure they reach those who need them most.
Washington Post
13-07-2025
- General
- Washington Post
What this 100-hour undertaking shows about public spaces
Warning: This graphic requires JavaScript. for the best experience. In May and June, I spent 100 hours painting my largest mural yet — a 2,000-square-foot wall in NoMa, in what sociologists call a 'third place': a space for socializing that is neither work nor home. A map showing where the mural resides. 'Endless Summer' mural, 200 Florida Ave. NE FLA. AVENUE NE Metropolitan Branch Trail N.Y. AVENUE NW Gallaudet University NoMa Union Market Union Station D.C. National Mall U.S. Capitol Source: Google Earth 'Endless Summer' mural, FLORIDA AVENUE NE 200 Florida Ave. NE Metropolitan Branch Trail NEW YORK AVENUE NW Gallaudet University NoMa Union Market Union Station D.C. National Mall U.S. Capitol Source: Google Earth Nicknamed 'the bike lobby,' this large, roofed, open space is a public amenity that District planners required the developers to provide. The planners wanted an easy connection between Florida Avenue and the Metropolitan Branch Trail, a popular regional trail that connects the Maryland suburbs to NoMa and runs right by the site. The developers delivered by punching a corridor through their apartment building. Today, the constant foot and bike traffic through the space validates that idea. Andrea Limauro paints the 'Endless Summer' mural in NoMa. (Photos by Albert Ting) As with the spring season artwork for this series, I chose this wall for its location in relation to D.C.'s main climate risk in the summer: urban heat. The D.C. Department of Energy and Environment (where I work) projects that days in the summer with a heat index of 95 degrees Fahrenheit or above — often referred to as 'heat emergencies' — will increase up to three times by 2080. Story continues below advertisement Advertisement Because temperatures are not the same across the city — varying according to factors such as tree cover, proximity to water, topography and land use — some communities, often lower-income, experience even hotter summers. That's why I focused on Northeast Washington, where neighborhoods along the rail lines can feel up to 17 degrees hotter than the greener areas northwest of Rock Creek Park. The rail infrastructure itself contributes: Aboveground metal tracks routinely hit more than 135°F in summer (which forces trains to run slower for safety reasons) and radiate heat well into the night. The rail yards, and the industrial businesses that usually line them in cities everywhere, tend to have fewer trees and more heat-retaining surfaces such as asphalt and flat black roofs, exacerbating the urban heat island effect. Fewer trees, higher temperatures The wall's location, directly across from the busy national, regional, cargo and Metro rails in NoMa, felt perfect for this season's mural. Like the Georgetown artwork, this project also points to one of the few solutions we have to rising temperatures in dense urban areas: building more shaded third places for people to cool off. While tree cover is essential, it's not always feasible in tight urban spaces with mazes of underground infrastructure. Thus, creating shade through architectural and design solutions — from shade umbrellas and sails in parks to awnings along retail streets, to balconies in buildings — can also play a major role in cooling our cities. Explore the mural The mural depicts a large rising sun to evoke the summer heat that will replace the cool night. The landscape is an expanded view of D.C. north of Florida Avenue. The flora throughout is purposely wild as a reminder that nature will find a way to thrive. Drag to see the full on the dots to reveal details. Marvin Gaye Park This municipal park — which stretches 1.6 miles through several Northeast neighborhoods — is the city's longest. In 2006, it was renamed for the soul musician, who grew up in the area and started his career in Washington. Third places — especially when free, accessible, and welcoming — are crucial ingredients in creating real community. In a time of ever-expanding cities and deepening social disconnection, they are more important than ever. Yet they're disappearing. Urban design tactics intended to dissuade loitering and encampments end up creating unwelcoming and uncomfortable spaces for everyone. If you've struggled to find a free and comfortable place to sit in a U.S. city, this is probably why. Story continues below advertisement Advertisement This is not to say such concerns aren't legitimate. There is a housing and mental health crisis in the U.S., but poor design won't solve it. Design is not a substitute for a social programs. When we make spaces uncomfortable for some, we make them uncomfortable for all. The result is often that people with means and choices avoid these uncomfortable public spaces, which, ironically, end up being used only by the very people who were meant to be kept away. With the bike lobby, I wanted to show that the opposite approach, more equitable and democratic, should be the guiding principle for urban design: Universal comfort for all is more likely to lead to higher use and diffused ownership of the space. The mural depicts a large rising sun, along with landmarks from NoMa and communities northeast and northwest of Washington's old Boundary Street, which formed the northern boundary of the Federal City under the 1791 L'Enfant Plan. Today it's Florida Avenue. My goal was to make a space so beautiful that people would collectively care enough to maintain it. Story continues below advertisement Advertisement This is the second of four artworks Andrea Limauro is creating for his year-long 'Climate of Future Past' project about seasonal risks in four vulnerable communities around D.C. Limauro created the project in response to The Post's commission of four artworks in its 'Four Seasons' collaboration with the artist.
The Guardian
09-07-2025
- Climate
- The Guardian
Extreme heat is our future – European cities must adapt
Three years ago, in Zurich for the first time, I crossed a bridge over the Limmat River and saw people floating down it in rubber rings on their way home from work, some casually holding beers. The Limmat is so clear that it almost begs you not only to jump in, but to drink it. Paris's Canal Saint-Martin has never produced either desire in me – but sweltering in last week's 38C heat, I wanted to close my eyes, pretend it was the Limmat, and leap. Others weren't so hesitant; there was a line of people going up one of the footbridges over the canal waiting for their turn to jump, dive, backflip or just belly-flop into the water. As the climate crisis throws its destructive effects ever more fully in our faces, cities during heatwaves are their own type of ground zero. It's no secret that Paris lacks green space and tree cover, ranking at the bottom of MIT's Green View index. Last week especially, I found myself longing for the expansive green lawns of Parc Montsouris – along with its free, public sparkling water fountain (one of 17 across the city). With the sidewalks sizzling and the sweat dripping, how can we create more green spaces and more tolerable streets in a densely populated city, with housing stock so susceptible to increasingly intense summer heat? The answer seems to be to squeeze in bits of vegetation and traffic-calming measures wherever possible. A green wall near Sentier Métro station; bushes, trees, flowers and wildgrasses in former parking spots on Rue de Sully; the pedestrianisation of Rue Charles Moureu in the 13th arrondissement, and hundreds more streets like them to come. There is the 'urban forest' growing in front of Paris's city hall, which is the capital's third so far, after the 470 trees that replaced a torpid stretch of concrete and sun at Place de Catalogne, and a repurposing of old railway tracks in the 20th arrondissement. On Sunday, the mayor of Paris, Anne Hidalgo, inaugurated her infamous pledge to make the Seine swimmable again for the first time in a century. You might call it a gimmick, though there are Parisians excited to take the plunge. While none of these localised urban tweaks are a substitute for big-picture political action to tackle the climate crisis, we will need to use every adaptation available to make our cities tolerable in the face of extreme heat. Whether it is swimmable ponds or little pockets of shaded respite, these things all help. Here in Paris, for example, they are redoing an intersection near my apartment that is also home to a small square. Previously, everything was paved in heat-absorbing blacktop; now, the blacktop has been replaced with stone, which does a better job reflecting the sun, and half of the formerly paved surface area has been planted. The visual improvement is already incontrovertible, and in a few years, when the plants have grown to their full size, what was once a heat island will have been transformed into something far cooler and more convivial. Hidalgo's strategy hasn't been without its critics, but from the pedestrianised banks of the Seine to the proliferation of bicycle lanes, who could deny that it has been swift and high impact? According to Luc Berman at Le réseau vélo et marche, a collective working to improve cycling and pedestrian infrastructure, the percentage of trips made on bicycle in Paris has gone from 2% to 12% in the last 10 years, while car use declined from 12% to 4%. 'No other city in the world of this size has moved so quickly,' says Berman. 'It's an example of what political courage can achieve at the local level.' In the immediate aftermath of the Covid lockdowns, the city threw up concrete barriers seemingly everywhere to carve out space for bicycles, and allowed restaurants to spread out terraces into streets. Those temporary measures have now been transformed into permanent cycling infrastructure and permanent demand for the expanded restaurant terraces. Will it all be enough, though? My bedroom – off my building's inner courtyard – is fully protected from direct sunlight, but in last week's searing temperatures, sleeping was still a challenge. Marine Le Pen's far right is attempting to turn a demand for 'obligatory' air-conditioning into its cause célèbre, while of course opposing tackling the root cause of the heating, through the only forum significant enough to do so: the EU. When it comes to overheating retirement homes, schools, Métro trains and France's nuclear-powered electricity grid, other parties would be foolish to let the National Rally claim this ground – these spaces do need air-conditioning. But in Paris's 19th-century apartment stock, it's clear that it will not be coming to save us en masse. This is our future. For the moment, extreme heat is still just a week here, a week there of sweaty, sleepless nights, but it will get worse. The Canadian zoologist and climate activist David Suzuki recently declared that 'it's too late' to solve the crisis. We can, and should, do as much as we can as fast as we can to limit every 10th of a degree of additional heating, but we have harmed our present and our future in an irreversible way and we're already feeling it. All that cities can do is adapt. Some will do a better job of it than others. If that makes you go ugh, well – it's the heat talking. Alexander Hurst is a Guardian Europe columnist
The Guardian
09-07-2025
- Climate
- The Guardian
Extreme heat is our future – European cities must adapt
Three years ago, in Zurich for the first time, I crossed a bridge over the Limmat River and saw people floating down it in rubber rings on their way home from work, some casually holding beers. The Limmat is so clear that it almost begs you not only to jump in, but to drink it. Paris's Canal Saint-Martin has never produced either desire in me – but sweltering in last week's 38C heat, I wanted to close my eyes, pretend it was the Limmat, and leap. Others weren't so hesitant; there was a line of people going up one of the footbridges over the canal waiting for their turn to jump, dive, backflip or just belly-flop into the water. As the climate crisis throws its destructive effects ever more fully in our faces, cities during heatwaves are their own type of ground zero. It's no secret that Paris lacks green space and tree cover, ranking at the bottom of MIT's Green View index. Last week especially, I found myself longing for the expansive green lawns of Parc Montsouris – along with its free, public sparkling water fountain (one of 17 across the city). With the sidewalks sizzling and the sweat dripping, how can we create more green spaces and more tolerable streets in a densely populated city, with housing stock so susceptible to increasingly intense summer heat? The answer seems to be to squeeze in bits of vegetation and traffic-calming measures wherever possible. A green wall near Sentier Métro station; bushes, trees, flowers and wildgrasses in former parking spots on Rue de Sully; the pedestrianisation of Rue Charles Moureu in the 13th arrondissement, and hundreds more streets like them to come. There is the 'urban forest' growing in front of Paris's city hall, which is the capital's third so far, after the 470 trees that replaced a torpid stretch of concrete and sun at Place de Catalogne, and a repurposing of old railway tracks in the 20th arrondissement. On Sunday, the mayor of Paris, Anne Hidalgo, inaugurated her infamous pledge to make the Seine swimmable again for the first time in a century. You might call it a gimmick, though there are Parisians excited to take the plunge. While none of these localised urban tweaks are a substitute for big-picture political action to tackle the climate crisis, we will need to use every adaptation available to make our cities tolerable in the face of extreme heat. Whether it is swimmable ponds or little pockets of shaded respite, these things all help. Here in Paris, for example, they are redoing an intersection near my apartment that is also home to a small square. Previously, everything was paved in heat-absorbing blacktop; now, the blacktop has been replaced with stone, which does a better job reflecting the sun, and half of the formerly paved surface area has been planted. The visual improvement is already incontrovertible, and in a few years, when the plants have grown to their full size, what was once a heat island will have been transformed into something far cooler and more convivial. Hidalgo's strategy hasn't been without its critics, but from the pedestrianised banks of the Seine to the proliferation of bicycle lanes, who could deny that it has been swift and high impact? According to Luc Berman at Le réseau vélo et marche, a collective working to improve cycling and pedestrian infrastructure, the percentage of trips made on bicycle in Paris has gone from 2% to 12% in the last 10 years, while car use declined from 12% to 4%. 'No other city in the world of this size has moved so quickly,' says Berman. 'It's an example of what political courage can achieve at the local level.' In the immediate aftermath of the Covid lockdowns, the city threw up concrete barriers seemingly everywhere to carve out space for bicycles, and allowed restaurants to spread out terraces into streets. Those temporary measures have now been transformed into permanent cycling infrastructure and permanent demand for the expanded restaurant terraces. Will it all be enough, though? My bedroom – off my building's inner courtyard – is fully protected from direct sunlight, but in last week's searing temperatures, sleeping was still a challenge. Marine Le Pen's far right is attempting to turn a demand for 'obligatory' air-conditioning into its cause célèbre, while of course opposing tackling the root cause of the heating, through the only forum significant enough to do so: the EU. When it comes to overheating retirement homes, schools, Métro trains and France's nuclear-powered electricity grid, other parties would be foolish to let the National Rally claim this ground – these spaces do need air-conditioning. But in Paris's 19th-century apartment stock, it's clear that it will not be coming to save us en masse. This is our future. For the moment, extreme heat is still just a week here, a week there of sweaty, sleepless nights, but it will get worse. The Canadian zoologist and climate activist David Suzuki recently declared that 'it's too late' to solve the crisis. We can, and should, do as much as we can as fast as we can to limit every 10th of a degree of additional heating, but we have harmed our present and our future in an irreversible way and we're already feeling it. All that cities can do is adapt. Some will do a better job of it than others. If that makes you go ugh, well – it's the heat talking. Alexander Hurst is a Guardian Europe columnist
