Aug 7, 2019

Rising global temperatures wreak havoc on urban "heat islands"

Illustration: Sarah Grillo/Axios

Most U.S. cities are at risk of experiencing extreme heat thanks to the "urban heat island effect" that's causing cities to warm as much as 50% faster than the rest of the country.

Why it matters: July was the hottest month ever recorded globally, and it was especially brutal for major metros.

"The extreme heat we’re seeing right now is the result of both climate change and urban development patterns. Cities have to think about the long-term implications of the changing environment."
— Katharine Burgess, vice president of urban resilience at the Urban Land Institute

The big picture: Severe heat wreaks havoc on cities' infrastructure, like electric grids, and presents serious public health risks.

City planners and developers are rethinking urban design to keep buildings and people cool as temperatures rise, according to a new report by the Urban Land Institute first shared with Axios.

  • Extreme heat may be a material risk: Moody's, Fitch Ratings and S&P Global warned that credit ratings could take into account cities' strategies for dealing with climate change. That could significantly impact cities' ability to raise capital and finance projects.
  • Midsized U.S. cities can expect about a 1% GDP loss by 2050 due to increased expenses and reduced growth associated with rising temperatures.

By the numbers: On average, cities are 2°F to 6°F warmer than their surroundings. Because they are covered with sun-absorbing pavement and rooftops, cities can be up to 22 degrees hotter than surrounding areas.

  • Today, cities have on average 10 more extreme heat events per year than they did in the mid-1950s.
  • Heat islands cause about 20% of the formation of urban smog, which then traps even more hot air in a city.

What's happening: From an economic perspective, cities that plan for super-hot futures may have a competitive advantage as consumers' preferences change with the weather.

  • In Houston, a midtown throughway was narrowed to make room for 175 large trees to provide shade cover along the corridor, resulting in a 20-degree temperature reduction in shaded areas.
  • In Scottsdale, a mixed-use development placed clustered buildings at specific angles to provide shade to each other and to pedestrian walkways. A giant custom shade was installed above the central plaza.
  • In New York City, parking lots are being turned into green spaces and "cool roofs" are installed throughout the city.
  • In Toronto, all buildings of a certain size are required by law to install vegetation on rooftops to reduce ambient temperatures. Greening 5% of the city's rooftop areas is estimated to lower citywide temperatures by about 1 degree.
  • In Los Angeles, where 40% of the city is covered with pavement, roofing materials must meet new sun-reflecting standards, and some city roads are coated with light-colored, reflective coating.

The catch: Heat mitigation measures are expensive, especially for large-scale projects. In the near-term, increasing air conditioning will likely be the go-to cooling method, even though they give off heat that may increase local temperatures and, through emissions, worsen climate change.

The most intense daytime urban heat islands are Las Vegas, Albuquerque, Denver, Portland, Louisville, Washington, D.C., Kansas City, Columbus, Minneapolis and Seattle.

Threat level: The impacts of extreme heat are felt disproportionately by a city's most vulnerable populations — the homeless, elderly, young and those living in poverty. Low-income communities are also less likely to have air conditioning or access to pools or cooling centers.

The bottom line: Severe heat will force cities, especially those in already-warm climates, to find long-term cooling strategies to protect their people, infrastructure and economy.

Go deeper

Cities are rewriting zoning and land use rules to usher in AVs

Illustration: Rebecca Zisser/Axios

A growing number of U.S. cities, including Las Vegas, Minneapolis and Chandler, Arizona, are re-examining their zoning, land use, and transportation regulations to ease the way forward for AVs.

Why it matters: Cities are exploring changes to decades-old laws in the hopes of attracting new technologies and investment as well as the economic and quality-of-life gains that come with them.

Go deeperArrowAug 21, 2019

Cities track citizens' sentiment through social media

Illustration: Aïda Amer/Axios

Monitoring social media feeds is a common practice for major brands and companies trying to keep up with consumer sentiment and tastes. City governments are now tapping into those data streams to keep tabs on residents' chatter and complaints about what's happening around town.

Why it matters: Twitter and Facebook posts, when combined with other city tip lines and data collection tools, can be a gold mine of information about what citizens really think.

The big picture: Social media creates a wide-ranging sensor network of sorts that helps cities direct resources to what residents actually care about. But it can also be surprising for users who don't expect city staff to be paying attention.

What's happening: Zencity, a Tel Aviv-based Microsoft-backed startup, sells an AI-powered sentiment analysis tool designed to track citizen opinions so cities can gauge how they are performing. Zencity works with 75 communities and collects more than 1.5 million social media interactions each month.

  • "Cities need to know if they're doing a good job, but they don't have a feedback loop," said CEO Eyal Feder-Levy, citing low response rates to city surveys and low attendance at traditional town hall meetings. "This is the basic concept of meeting people where they are."

How it works: Zencity provides a dashboard that aggregates data points including social media posts, local news stories, messages received by cities' 311 portals, and online feedback forms. Zencity collects more than 1.5 million interactions each month, Feder-Levy said. AI is used to identify and sort trends, anomalies and public sentiment.

For example: Houston works with Zencity to gauge how residents are responding to changes in city services, such as a recent garbage pickup schedule change and a project equipping free WiFi on public buses and trains.

  • "A lot of the products and services we're rolling out don't have measurements attached," said Jesse Bounds, Houston's chief information officer. "We can look at usage for a metric for success, but what we wouldn't have is whether customers care, whether they're excited about it. We need to prove out the value of all these investments in our smart city infrastructure."
  • In Cary, North Carolina, a town of about 160,000, local officials used Zencity data to monitor how residents felt about the fleet of electric scooters that quickly appeared on sidewalks. Mixed feelings from residents led the city council to allow e-scooters but reserved the right to change the ordinance if needed.

The big picture: Cities naturally want to take advantage of the troves of information citizens are sharing on social media, but some people may not expect city administrators to "listen to" them when blowing off steam about a traffic jam or venting about a snow plow.

Privacy tensions bubbled up when law enforcement agencies were found to be using social media to monitor protesters and activists in 2016. After criticism, Twitter, Facebook and Instagram changed their policies to prohibit using their data for police surveillance.

That's where the distinction between passive monitoring and personal tracking is key, says Kelsey Finch, senior policy counsel at the Future of Privacy Forum.

  • "When we think of public monitoring, people jump to tracking individuals, which feels more targeted than tracking aggregate sentiment," she said. "It feels very different when people can put you in jail versus coming out to fix your pothole. People for the most part like to be lost in the crowd and the sense of security that comes along with it."

Many social media monitoring services, including ZenCity, aggregate data to show broad trends, heat maps and topics without singling out specific users. If city staff wants to drill down to an individual comment or comment thread, names are whited out.

Keep ReadingArrowAug 14, 2019

Debates ensue over congestion pricing

Morning commute on a busy Manhattan street. Photo: Spencer Platt/Getty Images.

How much cities should charge vehicles to drive on city streets and who should have to pay is the center of political debates, Chris Teale writes for Smart Cities Dive.

Driving the news: New York City is about to become the first to charge Manhattan drivers a congestion toll. Fees collected would fund public transit and infrastructure improvements.

Go deeperArrowAug 21, 2019