By Josh Foster, Ashley Lowe and Steve Winkelman
Washington, DC (February 1, 2011)- This report provides evidence of the value of green infrastructure for local climate adaptation based on significant net benefits and successful local action. In providing comparable cost, performance, and benefits data across a selection of green infrastructure practices, the report avoids equating each practice as a solution to a single climate related problem but rather shows that a mix of approaches is best.
For example, white roofs are often promoted as a panacea to reducing urban heat island effects while ignoring the value of vegetated roofs to both lower temperature and to manage storm runoff at comparable net benefit (even at higher initial investment). Instead, this report encourages consideration of the multiple benefits of single green infrastructure solutions, the trade-off among solutions to achieve multiple benefits, and how a combination of solutions may lead to the highest net climate adaptation benefits depending on local needs, capacities, and resources.
For example, a building with a combination vegetated, white, and blue roof, surrounded by green alleys incentivized under a downspout disconnect program, and encouraged by a permeable pavement ordinance, shaded by street trees, and buffered from floods by local wetlands, not only receives multiple net-benefits from green infrastructure but de facto is more adapted to and mitigates climate change. If all public and private property owners in a neighborhood, city, or county simultaneously implement these practices the result is greater overall climate resilience across a region.
This report provides evidence of the value of green infrastructure, for example:
* In Houston, TX, trees provide $1.3 billion in stormwater benefits
* Trees in Portland, OR, generate approximately $13 million per year in property tax revenues by increasing real estate values.
* Annual economic benefits of Washington DC street trees is $10.6 million, including $3.6 million for stormwater, $1.3 million for energy, and $5.1 million for property value.
* Portland, OR, invested $8 million in green infrastructure to save $250 million in hard infrastructure costs.
The Value of Green Infrastructure for Urban Climate Adaptation