By definition urban means “characteristics of a city.” The landscape of urban open spaces can range from playing fields to highly maintained environments to relatively natural landscapes.
When asked to describe an urban environment, few people would mention forests or fields, wetlands, beaches or gardens. Yet urban populations have long embraced the importance of open spaces. Whether sprawling over hundreds of acres like New York City’s famous Central Park, or comprised of a bench, a water fountain and a swing set like many of the “pocket parks” scattered throughout high-density neighborhoods across the country, a sunny day will find a vibrant green space full of people enjoying the outdoors.
Planned open spaces are an important part of urban life and contribute to the health and well-being of urban people. Car-free paths for running and biking, wooded areas with hiking trails, sports fields and children’s playgrounds all offer opportunities for exercise, recreation and socialization. P-patches and other community garden programs provide much needed access to fresh, nutritious, culturally relevant foods. Open spaces in urban areas can even represent economic opportunity, often hiring within the community for jobs in maintenance, environmental education and recreation leadership. Community members from all income levels can enjoy the benefits of urban open spaces, while property owners will appreciate the economic value added by their proximity.
In addition to their social and economic benefits, open spaces in the city provide significant ecological functions and values. Green spaces defined by wooded and grassy areas sequester carbon and reduce air pollution and surface runoff. Migratory birds often use urban parks and other conservation areas as resting points on long flights, while more permanent urban fauna rely on these areas for long term habitat. Shaded areas and bodies of water in parks can also help to cool the air in cities, helping to mitigate the urban heat island effect.
Many cities are beginning to look to the ecological benefits of green and open spaces as a response to climate change. “Linear parks” in particular are taking center stage, as they can often be constructed on unused channels of land like abandoned rail lines or the swaths of green that run below power lines. These green spaces often feature networked bike and walking trails, improving the commuting experience for many while reducing emissions and the urban population’s reliance on fossil fuels.
Climate change is impacting and could continue to affect urban areas in a variety of ways. Different regions are vulnerable to different climate pressures, however, urban areas throughout the U.S. all face increased risks due to more extreme temperatures and altered precipitation trends. Due to the nature of the built environment, cities are already typically warmer than surrounding rural areas, a phenomenon known as the urban heat island effect. Increased summer temperatures related to climate change will exacerbate this effect, as well as creating higher energy demand in the form of artificial cooling.
Extreme weather marked by sudden, heavy precipitation is also associated with climate change and can be expected to have a particular effect on cities and their related ecologies. The urban built environment is comprised largely of impervious surfaces such as pavement, concrete, glass and steel. Natural areas are capable of absorbing the effects of heavy rainfall, with porous soils soaking up much of the water and distributing it into underground aquifers, and root systems controlling erosion. The impervious surfaces that comprise cities, however, allow water to collect and travel quickly across them, often picking up trash and pollutants on their way to the city storm drain. City drainage systems can become overwhelmed and backed up, causing flooding and property damage. Low income people and members of underserved communities may live with the effects of flooding for years, lacking the insurance and resources to fully address damages. Mold, mildew, and structural flood damage can be of lasting detriment to public health in these circumstances.
The impacts of climate change are likely to worsen many resource management problems that urban areas already face. Addressing the additional stress of climate change may require new approaches to managing land, water, waste, and ecosystems. As conservation experts and long-term resource stewards, the land trust community is uniquely poised to inform land and water management dialogs.
The land trust community is responding to urban land management challenges associated with climate change in various ways. For example, The Trust for Public Land, through the Climate-Smart Cities program, is working with cities like New York City and others across the country to identify opportunities to enhance green spaces for multiple benefit projects, including converting an out-of-service rail line into an elevated bike and pedestrian path connecting several Queens neighborhoods and installing playgrounds based on green design principles – like porous paving and rain gardens – in low income urban neighborhoods. In Seattle the Evergreen Land Trust partners with members of intentional communities to preserve affordable housing opportunities, informed by principles of cooperation, land stewardship, and sustainability.
While there is no one-size-fits-all approach to address climate impacts, more and more, conservation organizations are working with their communities to identify opportunities to reduce vulnerabilities and prepare for changing temperatures. Agencies are making similar strides to implement projects that reduce risks and plan for resilience by incorporating adaptation, mitigation, and engagement into their strategic goals and objectives.