The Green Seattle Partnership is an ambitious effort with a long range goal. But if we are successful we will leave a legacy of a green Seattle for our children and generations to come.
Urban forests give us a higher quality of life through a cleaner environment and the ability to enjoy nature close at hand.
According to Seattle Public Utilities data, Seattle’s forests provide the equivalent of $1 million per year benefit in stormwater management by temporarily holding water that falls as rain during heavy storms and releasing it slowly as it drains through forest soils. Forested parklands can increase adjacent residential property values 15%, benefiting both landowners and the city through increased tax revenue. And as citizens are encouraged to live more densely within the urban core, and residents have less access to private open space, amenities such as public parks and greenbelts make the city more desirable. Services that the City gets from trees, called “green infrastructure benefits” amount to $149 per year for each street tree (source: Western Washington and Oregon Community Tree Guide, USDA Forestry Service 2002)
In 1999, American Forests, a world leader in the science and practice of urban forestry, analyzed Seattle’s urban forest. The group concluded that from 1972 to 1996 the city lost 46% heavy tree cover and 67% medium tree cover. That loss cost Seattle $1.3 million per year in rainwater storage and management capacity and $226,000 per year in air pollution-related health care costs.
Forested parklands also clean the air. All trees can capture carbon dioxide and help remove soot and other pollutants, but our native conifer trees do it best because they continue to grow all year round. For example, the average acre of conifer forest captures 13 tons of carbon dioxide each year. Forests do this by incorporating carbon from the atmosphere into the wood mass of the tree. At the market rate of $6 per ton of carbon absorbed, this process, known as “sequestration,” provides city residents $195,000 of annual air cleaning service. In addition, conifers along roadways trap soot on their leaves, which results in cleaner air and reduced incidence of asthma.
More and more studies emphasize the importance of nature to people’s health and well-being. Just being outside under tree cover has proven to reduce stress and improve creativity, memory and cognitive function. Spending time together in nature has been shown to increase our capacity for empathy and compassion, make us act more generously, and decrease aggression and bullying. As our cities rapidly grow, our few natural refuges are all the more critical.
The Pacific Northwest is an incredible natural playground. But having nature close to home is hugely important too. Natural open space within cities vastly improves our urban environmental health, and also provides access for residents without the means – including time – for frequent trips to the mountains. City parks are many people’s first contact with the great outdoors, and can spark a lifelong connection with the natural world.
But we don’t have these incredible resources right in our backyards if we don’t protect them. They are our natural infrastructure, and just like bridges and roads, need to be maintained if we are going to be able to continue enjoying all they have to offer. If every Seattle resident volunteered just three times a year, we would be able to care for every acre of forested parkland in the city and ensure a green Seattle into the future.