How investing in green infrastructure helps cities manage the effects of the climate crisis and creates healthy communities

• Green infrastructure can help cities solve climate problems and promote the health of residents.
• Things like urban greenery can also offer environmental, social, and economic benefits to a city.

Setting ordinances to build more green roofs, planting trees and native plants, and designing community green spaces are just a few ways that many cities are investing in green infrastructure to solve climate-related problems and promote the health of residents.

Expanding greenery in urban areas, for example, helps cities manage stormwater, reduce energy use, improve air quality, enhance the quality of life of residents, reduce the urban heat island effect, and boost local economies.

"A lot of cities are becoming more concerned with environmental stressors that climate change is bringing," such as sea-level rise, saltwater intrusion, and more intense tornadoes and storms, Gail Hansen, an associate professor at the University of Florida's Environmental Horticulture Department, told Insider."One big trend is resilient city plans, and using green infrastructure is a big part of those plans to protect cities from these stressors," she added.

Last year, 31 mayors of cities, including Los Angeles, New Orleans, Seattle, and Austin, signed the C40 Urban Nature Declaration to show their commitment to green infrastructure.

The cities pledged to convert up to 40% of city surfaces to green or blue, that's water-related features, infrastructure by 2030 — including trees, urban forests, ponds, and parks with sustainable drainage systems — and ensure that 70% of their residents have access to green or blue public areas, such as wetlands or ponds, within a 15-minute walk or bike ride.

"Cities have to be very future thinking," Hansen said. Those invested in green infrastructure can become environmentally healthier and more resilient, which provides opportunities for residents and economies to thrive.

Green roofs and other infrastructure are becoming a focus for cities

One green-infrastructure trend is a green roof, which is a layer of vegetation planted over a waterproofing system atop a building. Plants absorb rainwater, preventing it from running off the roof's surface and potentially causing flooding.

"Cities are seeing their green roofs as an opportunity to provide a variety of infrastructure benefits to help us future-proof our cities against climate change," said Steven Peck, the founder and president of Green Roofs for Healthy Cities.The benefits include providing shade, cutting a building's energy use, and reducing the surrounding air and surface temperatures, according to the US Environmental Protection Agency. Green-roof temperatures can be up to 40 degrees Fahrenheit lower than traditional roofs and reduce citywide temperatures by about five degrees.

Managing heat islands creates more equitable communities, as low-income areas tend to suffer most from overheating, which results in poorer air quality and diminished health, Peck added.

Chicago has been a leader in green-roof installations in the US, with more than 500 such roofs in the city. San Francisco, New York City, and Toronto also have ordinances requiring green roofs for some new and renovated buildings.

Peck said green roofing that incorporates biodiversity — where plants are used to attract insects, birds, and wildlife — is an emerging trend. The green roof at the Javits Center in New York is an example, as it's home to honeybees and several species of birds and bats.

Biodiversity in other green spaces encourages wildlife habits and promotes cleaner air and water, Hansen said. Some projects feature native plants to strengthen the local ecosystems, and trees and urban forests boost biodiversity and provide tree-canopy coverage.

Biophilic design is also being incorporated in green landscaping projects, Hansen said. Biophilia refers to people's innate need for nature, and Hansen said city governments see adding parks, walking and biking trails, and greenery that are all easily accessible as a way to boost residents' physical and mental health.

"A lot of cities are thinking about ways to create opportunities for people to have more recreational spaces where they can interact with nature, even if it's a little pocket park," she said. "They're also looking at how these landscapes can meet the needs of diverse cultures in a community."

Phoenix, St. Louis, Miami, and Washington, DC, are some of the metros that are part of the Biophilic Cities network, showing their commitment to improving the connection between residents and nature.

Green infrastructure offers environmental, social, and economic benefits

Urban greenery filters air and water, which makes communities healthier, Hansen said. Research showed that increasing access to green spaces decreased mortality, and that urban green spaces reduced stress and improved mental and physical health.

Green infrastructure also boosts local economies by encouraging tourism dollars and attracting developers. Buildings with green roofs, for example, eliminate problems like flooding and excess heat, and they add recreational space. Peck said adding amenities and making properties more sustainable could increase property values and attract residents and businesses.

Transforming old industrial structures and sites, such as abandoned rail systems, into parks could help cities revitalize areas and drive economic development, Hansen said. She cited New York's High Line, a linear park and trail system built on a former railroad line, as an example.

Some of the challenges cities face in implementing these projects include funding, stakeholder and community buy-in, and outdated city codes and ordinances, Hansen said. She added that some were overcoming the challenges by creating public-private partnerships and using data to show how green infrastructure benefits the city and its residents.

Still, incorporating green infrastructure into their resiliency plans is imperative for cities, she said, adding, "It's almost become a must-have for cities to figure out how they're going to weather — no pun intended — a lot of these big issues."