Green infrastructure is becoming a hot topic. This week is the 2012 GreenGov Symposium, September 20 was the White House Conference on Green Infrastructure, and August saw the first annual Mid-Atlantic Green Roof Science & Technology Symposium, Redefining Green Roof Science. Colleges and universities looking at green infrastructure include Harvard, Carnegie Mellon University, Villanova, Swarthmore College, University of Waterloo, and Penn State. Some projects are quite large; in 2010, Colorado University, Boulder received $2 million from the National Science Foundation to build a living wall.
CCAP’s The Value of Green Infrastructure for Urban Climate Adaptation and the EPA’s compendium of strategies to reduce the urban heat island effect discuss several types and benefits of green infrastructure. Here we touch on three: green walls, artistic downspouts, and green roofs.
Green Walls, Living Walls, Landscape Walls
“Green walls” is an all-encompassing term that is used to refer to all forms of vegetated wall surfaces. These include green façade (plants growing onto and over specially designed supporting structures), living walls (distinct wall panels that include growing medium or liquid nutrient), and landscape walls (exterior living structures used to delineate boundaries, such as a hedge).
Benefits of these structures are numerous. Studies in Oregon demonstrated that non-vegetated areas can exceed temperatures of 50 °C (122 °F) in July while vegetated areas remain at 25 °C (77 °F) (Luvall and Holbo, 1989). Green walls have been shown to reduce temperature fluctuations at the wall surface from 5 to 30 °C (41 to 86 °F). Street-level air pollution can be reduced by as much as 40 percent for nitrogen dioxide and 60% for particulate matter at the source, and by as much as 75 percent downwind of large green walls. Green walls that use appropriate plants can act as natural “bio-filters” for some volatile organic carbons and other pollutants when implemented as part of an integrated building strategy. Other benefits can include stormwater runoff reduction, building energy efficiency, improved interior air quality, urban agriculture, on-site waste water treatment, increased biodiversity, LEED credits, marketing and green branding, building facade protection, aesthetic improvement, noise reduction, local job creation, and ease of construction (interested in making a living wall?). In addition, vegetation in urban areas has been shown to increase mental well being, biodiversity and residential property values.
In appropriate areas, rain gutters, downspouts and rain barrels can help manage water runoff. The EPA Office of Sustainable Communities sent us images of artistic downspouts. Some drain water off roofs and into rain gardens, others have plantings in the drain pipe itself.
This post is part of CCAP’s blog series, “What Does Climate Resilience Look Like?”, which highlights adaptation images from around the world addressing a variety of climate impacts and resilience solutions. Have a climate resilience image to share? Please send us the photo by Twitter, Facebook, or email. (Please include the Who What Where: Who took the photo? What is the adaptation technique? Where is it located?) We are especially interested in examples that advance multiple goals such as GHG emission reductions and sustainable economic development.