WORLD CITIES DAY

OCTOBER 31

World Cities Day: Rethinking the Relationship Between Cities and Nature

Cities are often seen as the opposite of nature, but in reality, they exist within it. Every building, park, and sidewalk is part of a larger ecosystem, connected through air, water, and soil. It can be easy to forget this relationship, but cities depend on nature’s systems such as clean air, fresh water, and stable climates to function. World Cities Day, observed on October 31, is a reminder that urban environments are not separate from the natural world but are shaped by it. The United Nations established this day to encourage sustainable urban development and to highlight how cities can be designed to support both people and the planet. With more than half of the world’s population now living in cities, and that number expected to grow to nearly 70% by 2050, how we build and manage these spaces will determine the future of community and environmental health.

What does a city look like when it actually works for people and the planet? 

Urban sustainability doesn’t have to be flashy or futuristic. In fact, the simplest ideas often make the biggest difference. Street trees planted along sidewalks help cool the air, filter pollutants, and provide homes for birds and insects. Buildings that are designed to use natural light and ventilation can dramatically cut down on energy use. Thoughtful zoning and city planning ensure that public spaces are safe and accessible for pedestrians and cyclists. Reliable public transit lowers pollution, reduces traffic, and connects people to opportunities that they may not have access to otherwise. Each of these changes may seem minor on its own, but together they create communities that are healthier, more resilient, and better equipped to adapt to climate change and rising global temperatures.

Urban parks are one of the most effective tools for bringing nature back into dense environments. Besides serving as pleasant shared spaces to relax and socialize, they have an important role as green infrastructure. The Trust for Public Land found that areas near parks can be several degrees cooler than nearby neighborhoods without them, which helps protect residents during heat waves. Trees act as natural air conditioners by releasing water vapor and shading pavement, which can otherwise trap heat. Parks also offer people mental and physical health benefits, as research shows that time spent in green spaces can lower stress, improve focus, and encourage exercise. In many communities, park access is an equity issue. Low-income neighborhoods often have far fewer green spaces, meaning residents are more exposed to pollution and extreme heat. Expanding parks and tree canopies in these neighborhoods not only cools cities but also reduces health disparities. 

Community gardens are a great example of how urban life and nature can coexist. They are typically small plots of land maintained by local residents that grow fresh fruits, vegetables, herbs, and natural medicines. These are small plots of land, maintained by residents, where neighbors grow fruits, vegetables, herbs, and flowers. These gardens create access to fresh produce in areas where grocery stores may be inaccessible or unaffordable, and they provide a space for connection and learning. A single community garden can transform an empty lot into a hub of biodiversity where pollinators thrive and children learn where their food comes from. They also help with stormwater management by absorbing rainfall that might otherwise contribute to flooding. The Nature Conservancy’s urban program has documented how cities that invest in community-led green spaces see improvements in air quality, soil health, and social cohesion. Examples can be found all over the world. New York’s GreenThumb program supports more than 500 community gardens in all five boroughs of the city. Bethlehem, Pennsylvania, which is categorized as a food desert due to its lack of accessible grocery stores within walking distance, has three community gardens maintained by community members and Lehigh University students. Singapore has a network of rooftop community farms that bring local food production into one of the most urbanized places on Earth.

Water management is one of the most overlooked but vital parts of city planning. As climate change leads to more intense rainfall and rising sea levels, many cities are rethinking how to live with water instead of fighting against it. Copenhagen’s Cloudburst Management Plan redesigned streets, plazas, and parks to absorb and redirect stormwater during heavy rain, turning potential flood zones into temporary canals or wetlands. In Rotterdam, the Netherlands, public squares double as rainwater basins, filling up during storms and drying out into playgrounds afterward.

Global and local efforts making cities greener 

While city-level planning drives most large-scale change, meaningful advances often begin with nonprofits, community groups, and local policy efforts. When governments, residents, and relevant organizations work together, their efforts are amplified and often longer-lasting. Groups like C40 Cities support mayors taking on climate and air quality challenges together, sharing research on co-benefits so leaders can defend policies that clean the air and strengthen local economies. ICLEI (Local Governments for Sustainability) is a global network of local governments advancing zero-emission and circular development with practical tools and peer support. Bloomberg Philanthropies partners with cities to provide technical support and data tools that make climate goals achievable. Organizations like the Trust for Public Land work on the ground to ensure every resident has access to parks within a ten-minute walk. Tree Fredericksburg, a nonprofit in Virginia, has planted more than 8,500 trees since 2008 in partnership with the City of Fredericksburg to expand canopy cover, restore greenways, and educate residents about urban forestry.

Many of these efforts succeed because they focus on collaboration. A single pilot project, such as a small bike lane or green roof program, can spark larger policy shifts when other cities see its success. Partnerships between residents, nonprofits, and municipal agencies build trust, and that trust leads to smarter, longer-lasting changes. For example, in Los Angeles, community-led advocacy around air quality helped shape the city’s Clean Up Green Up initiative, which established “green zones” to protect residents from industrial pollution while creating new green jobs. This collaboration shows that meaningful urban transformation doesn’t always require huge budgets, but instead builds on shared goals and sustained effort.

3 Actions you can take to make your city greener

  1. Join or start a community garden — Transforming underused lots into green, shared spaces enhances food access, community connection, local biodiversity, and improves community health.

  2. Volunteer for a local tree-planting or urban forestry group — Partnering with organizations like Tree Fredericksburg or your city’s parks department helps expand canopy cover, reduce heat, and strengthen local ecosystems

  3. Engage with local urban planning efforts — Attending city council and planning meetings gives residents a voice in designing neighborhoods to be safer, greener, and more equitable

HOW CAN I GET INVOLVED?

  • Volunteer: Join us in our efforts to promote environmental awareness and sustainability in your community. Whether you have a few hours or a few days to spare, your help is invaluable!

  • Partner with Us: If you're part of a nonprofit, business, or government organization, consider partnering with the Environmental Alliance for collaborative projects or events. Together, we can make a bigger impact!

  • Stay Informed: Sign up for our newsletter to receive the latest news, events, and ways to participate in our initiatives.

  • Attend Events: Participate in our upcoming events and awareness days. Check our calendar for dates and details.

  • Spread the Word: Share our mission with your network. Follow us on social media and help us raise awareness about environmental issues.

  • For more information: visit www.worldcitiesday.org