Urban or built environment

Lisbon is facing an increasing threat linked to climate change due to its geographical location and climate (6), which has had a negative impact on health and quality of life in the city (5). Its average annual precipitation is decreasing, although the city experiences more winter precipitation. This results in longer droughts and more seasonal flooding, which reduces water retention and soil conservation (6). Average temperatures are increasing by 14°C per year, with maximum temperatures up to 5°C higher (6).
As an adaptation measure to these challenges, the LIFE LUNGS project aims to increase Lisbon's resilience by implementing green infrastructure and promoting related ecosystem services (1, 3, 5, 6). Thus, it focuses on measures aimed at coping with temperature increase, mitigating the effects of heat waves and water scarcity, which are expected to become more frequent, being in line with the climate policies adopted by the municipality. The project runs from 2019/2020 to 2024/2025 (1, 5, 6). It aims to address cross-cutting issues such as climate, water and biodiversity (3). The project expects to work hand in hand with the City of Malaga, which has been developing projects aimed at adapting the city to climate change. It is expected to replicate the work in Malaga and post-project to 2 national territories, and 1 in the EU (4). It is also intended to transfer the project work to be implemented in private areas that are part of Lisbon's green infrastructure, and to disseminate and technically train municipalities of the Lisbon Metropolitan Area and other municipalities committed to climate change adaptation (4).

Public spaces in Colombo are disappearing due to rising land prices, causing infrastructure issues that harm citizens' health, especially in low-income areas (3). One proposed solution to address the problems caused by rapid urbanization is the creation of community gardens, which can at least improve low-income residents' diets and immune systems and address malnutrition (3).
Considering the limited urban space for both citizens and other living beings, the organization Eco-friendly Volunteers decided to create a community garden. The Metta Garden in Colombo (1, 2) aims to bring back urban biodiversity through organic home gardening, generating healthy food for people and creating living space for many other animals and plants (2). Following the Buddhist concept of Metta (loving-kindness to all beings), it promotes walking meditation paths and facilities to experience nature using all five sensory organs (1), in addition to being a place for experiencing loving-kindness for both human and non-human living beings, seen and unseen (4, 5).
It has become a training institute for many stakeholders seeking to grow organic food and earn a better income through the high demand for organic products (2). At the same time, it serves as a biodiversity spot, attracting butterflies, bees, and other forms of wildlife to an urban environment (2).
The area is located in the middle of a semi-urbanized area, on the outskirts of Boralesgamuwa (2, 3). Maintained by a group of volunteers, it features a greenhouse and a plot of land of around 5,000 sq feet, populated with vegetable patches, a butterfly garden, flowers and rare medicinal plants (3, 4). The garden was divided into four sections representing the Buddhist elements: water, heat, air, and solid. Each section features specific plants and designs, like a pond for water, a compost pit for heat, tall plants for air, and a rock garden for solid. The layout follows a mandala design based on permaculture principles (4).

In 2018, the City of Detroit implemented a drainage charge to help cover the costs of capturing, conveying, pumping, treating, and safely returning combined sewage to the Detroit and Rouge Rivers (1). The charge is calculated based on each parcel’s impact on the sewer system, particularly by measuring impervious acreage (1). Since then, this fee has posed significant challenges for one group in particular: Detroit’s houses of worship (2). Churches, with their large roofs and parking lots, face higher monthly drainage charges, creating financial strain for many faith leaders (2).
To support these institutions, Sacred Grounds has been providing grants, labor, and design assistance to install projects that reduce water bills and drainage fees (2). Sacred Grounds collaborates with the National Wildlife Federation, Friends of the Rouge, and Sierra Club of Michigan to implement these projects through the city’s green credit program (2). A recent initiative involved installing four rain gardens located on the perimeter of St. Suzanne Our Lady Gate of Heaven Church (3). These bioretention gardens, funded by several private and public actors and led by Detroit Future City, diverts water from 20 large downspouts, redirecting an estimated 500,000 gallons of runoff annually away from the municipal sewer system (3, 4).
In addition to managing water, the gardens foster a thriving habitat for pollinators and adds beauty to the area (3). St. Suzanne’s commitment to environmental education includes engaging over 130 youth and adults in training programs that build pathways to STEAM careers and opportunities where local residents are often underrepresented (4). The church also features an innovative, eco-friendly outdoor classroom developed by students, further supporting their sustainability mission (4).

The environmental impact of golf has led to growing calls to make the sport more sustainable (1). Golf course maintenance often involves carbon-intensive fertilizers, frequent mowing, and, in some cases, the clearing of forests or trees that naturally absorb carbon dioxide to make room for expansive fairways (1). However, the Tournament Players Club (TPC) Michigan is working to create courses that benefit both golfers and the environment (2).
Fifteen years ago, the site was a neglected floodplain along the Rouge River, initially purchased by Henry Ford in 1915 and once littered with community waste and old motor parts from the Ford Motor Company (2-3). Today, it has been transformed into an 85.8-hectare course that supports a diverse range of wildlife, including birds, fish, foxes, and coyotes (2). Led by Jack Nicklaus, the restoration aimed to turn this former waste site into an eco-friendly course (2). With guidance from Audubon International, the course was converted into a wildlife sanctuary, becoming the world’s first golf course to receive the prestigious John James Audubon Environmental Steward Award for ecological restoration (2).
TPC Michigan features native Michigan plants, such as viburnums, which produce berries for wildlife, along with various native grasses (2). To prioritize environmental stewardship, the course managers have created buffer zones to protect natural habitats and conserve water by using coring methods to monitor soil moisture (2). Pesticide use is minimized; instead, staff monitor for signs of disease or pests and test the soil to determine the specific nutrients needed for the turf (2). The course’s links-style layout includes rolling fairways, tiered greens, and natural wetlands, with tee options ranging from 5.5 to 6.4 meters (4). By establishing a wildlife sanctuary, TPC Michigan offers golfers a unique experience that fosters a connection with nature (3).

The stretch of the Great Lakes basin ecosystem from southern Lake Huron through western Lake Erie forms a unique urban refuge where life thrives with beauty and resilience. Known as Metropolitan Detroit, this region is where the Community Foundation for Southeast Michigan and many partners are working to create The Great Lakes Way by connecting 160 miles of greenways and 156 miles of water trails (1).
The vision for the Great Lakes Way project is to ensure that all residents and visitors of southeast Michigan—people of all ages, backgrounds, ethnicities, abilities, and interests—feel connected to the water resources, welcomed on its trails, and able to enjoy the benefits and opportunities these access points provide (1). To bring this vision to life, the project plans to link 160 miles of greenways and 156 miles of blueways, connecting people to a range of world-class freshwater, wildlife, and recreational opportunities. These include fishing areas, bird migration pathways, parks, working waterways, preserved woodlands, and restored wetlands (2).
The Great Lakes Way project connects existing assets, supports accessibility and equity, and promotes the Great Lakes Way to both residents and visitors through marketing and communication efforts (2). There are 26 points of interest that will serve as connection hubs along the Great Lakes Way (2). In Detroit specifically, the focus is on connecting 13 culturally or historically significant destinations, as well as locations known for their environmental and ecological importance or as regional landmarks (2).
Rich in world-class fisheries, migratory flyways, parks, urban centers, small towns, preserved old-growth woodlands, and restored wetlands, the Great Lakes Way offers unique experiences that can only be found here. By uniting the natural and cultural assets the Great Lakes Way designation aims to emphasize and expand the essential linkages needed to further connect this remarkable region. (2,3)

Across Detroit, neglected properties and vacant lots are a common sight (1). Nearly three-quarters of Detroit residents report that there is currently deterioration—defined in the survey as a building or property visibly declining due to long-term neglect—in their neighborhoods (1). One organization, Rescue MI Nature Now, a Michigan nonprofit, is dedicated to transforming these neglected areas into beautiful, functional spaces that benefit both people and wildlife (2).
In 2022, the organization purchased property from the Detroit Land Bank that was marked for demolition (3). Following extensive renovations, the building—now named the Innovative Youth Studio—has become a hub for multiple community initiatives. These include a community garden across the street, a culinary studio that teaches young people how to prepare nutritious meals, a pollinator studio that educates on the critical role pollinators play in the food chain, and a hydroponic studio where plants are grown using nutrient-rich water instead of soil (3).
The pollinator project, developed in partnership with the U.S. Fish & Wildlife Service, supports small bee colonies by planting areas with trees, flowers, and native plants (2). To further enhance biodiversity and support butterflies, bees, and birds, Rescue MI Nature Now partnered with Bowling Green State University to gain insights into pollinator biodiversity and habitat potential (2). Through this initiative, the organization aims to raise awareness about pollinators, highlight their positive impact, offer guidance on creating pollinator-friendly spaces at home and enhance the quality of life for local residents and communities (2).
Additionally, the organization runs a Sustainable Youth Stewardship Program, where young people learn to garden, grow trees, identify various plants and invasive species, and practice conservation skills such as creating pollinator habitats and managing community gardens (3).

To reduce the risk of urban flooding, the city of Seville, through its metropolitan water company Emasesa, established several "sustainable urban drainage systems". One of the pilot locations is on the Avenida de las Ascociaciones de Vecinos, where a rain garden complemented by an infiltration zone was established. The main aim of the project is to reduce the risk of flooding, but the system can also improve the urban landscape by offering green space, preventing desertification and reducing pollutants carried by runoff [Ref. 1-4]. After implementation, the project was shown to be effective during heavy rain [Ref. 5]. The system can store up to 34 m2 of water and reduce flow rates to the sewage network by 69 % and the total runoff to sewage by 93 % [Ref. 3-5]. The project was initiated and led by Emamesa, while two different companies were employed to design and construct the system [Ref. 1, 2, 6, 7]. The total budget of the project, which also included some renovations of grey infrastructure along the street, was 165000 EUR [Ref. 1].

In May 2020, CityLAB Berlin launched "Gieß den Kiez", an interactive platform designed to support Berlin's urban trees by fostering collaboration between citizens and the city. The platform enables voluntary civil society efforts to help water the city's endangered tree population. It features a map that visualizes nearly all of Berlin's street and park trees, complete with data such as water requirements, age, and species. Citizens can create profiles, adopt trees, and mark them as ‘watered’ within the app, making it easy to track contributions to the health of Berlin’s trees. (Ref. 2)
Berlin's trees face growing challenges due to increasing temperatures, reduced rainfall, and exposure to road salt in winter. The hot summers of 2018 and 2019 highlighted the urgency of supporting the city’s trees, which provide cooling shade, clean air, and habitats for numerous animal and plant species. To address this, "Gieß den Kiez" was developed as a platform where authorities, volunteers, and civic society could collaborate to prevent tree dehydration.
The platform maps over 625,000 trees across Berlin and offers additional tools, such as rainfall data from the last 30 days and the locations of public water fountains, which can be used for watering trees. By connecting data from city authorities, the German Weather Service, and OpenStreetMap, the fully open-source platform allows for transparency and accessibility in its operation. (Ref. 6)
The project has proven highly successful in Berlin, with over 10,000 participants actively watering trees, and its model has been adopted in other German cities like Leipzig. "Gieß den Kiez" not only exemplifies a practical response to urban climate challenges but also fosters a sense of shared responsibility and community engagement in caring for urban green spaces. (Ref. 6)

The project focused on implementing multilayer blue-green roofs in four Italian cities—Cagliari, Palermo, Perugia, and Viterbo—as part of a broader European initiative to address climate change impacts in urban environments (1,3). Spearheaded by a collaboration between multiple Italian universities and the Dutch company Metropolder, the project began in 2019 (1,3). The primary goal is to enhance urban resilience by integrating green infrastructure capable of mitigating climate-related urban hazards such as flooding and heat waves, which are increasingly severe due to climate change and urbanisation (2,3).
The multilayer blue-green roofs combine the ecological benefits of traditional green roofs with an added water storage layer, allowing them to retain rainfall and manage runoff effectively (2,3). This dual function helps reduce pluvial flooding and the urban heat island effect, while also improving thermal insulation in buildings (2,3). Each installation was planted with low-maintenance, climate-adapted vegetation, and equipped with sensors to monitor ecohydrological and thermal performance over several years (1,3). These roofs are capable of retaining up to 100% of rainfall from significant events, thereby easing the burden on urban drainage systems and contributing to climate adaptation in Mediterranean cities (2,4).

The urban garden in Miraflores park (Huertas las Moreras) was established already in 1991 on an old waste dump and contains 10500 m2 of plots for locals to grow fruits and vegetables [Ref. 1]. The creation of the gardens was initiated by citizens who formed an association and implemented it in cooperation with the City of Seville. The citizens were discontent with the lack of green space in the area, and the urban gardens came to be alongside Miraflores Park, which was also pushed by the locals. The initial goals of the gardens were to allow locals to produce their own food and to host educational activities [Ref. 2]. More recent developments exemplify the focus on education and knowledge. In 2022, the citizen science project "Planta Bienstar" was carried out in the gardens, where high school students measured the lead levels in the soil and crops. The project aimed to investigate if lead levels posed a health risk and if the gardens could reduce levels over time. The project was organised by the non-profit Descubre Foundation and funded by the foundation and the regional Government of Andalusia. The project relied on the knowledge and efforts of the citizens, the students and gardeners in an intergenerational collaboration where the young could learn methods from their elders [Ref. 3, 4].