Greening Our Cities, Cleaning Our Environment, Improving Our Health
Cheryl Kollin, DirectorUrban Ecosystem Center
American Forests
The Urban Heat Island
Urban Heat Island Impacts An average of 381 people in the U.S. die of heat-related deaths
each year. (Cool Houston)
When the temperature rises above 90 degrees F. cities can not meet EPA standards for air quality. When the temperature is reduced to 70 degrees F., all communities can. (Akbari, LBL)
Air Quality and Asthma
8.6 million U.S. children have asthma, a 37% increase in 2 years (American Lung Association, 2003)
1996 Olympic Games in Atlanta spurred a 30% decline in traffic and a 45% drop in emergency room visits for children
1 acre of trees= absorbs 2.6 tons of CO2=1 car driving 26,000 miles annually
Trees are the Lungs of the City Absorbs pollutants
Stores and sequesters atmospheric carbon in trees’ wood
Provides direct shade on buildings, reducing their energy consumption.
Cool indirectly by evaporating water from their leaves, a natural air conditioning effect
The Natural Gym
Obesity rates have increased 60% in the last 10 years to 59 million adults
Obesity related health care costs exceed $100 billion per year, which is more than smoking related costs
If you provide walk and bikeways in attractive settings, they will come.
Nature’s Sunscreen
Melanoma has doubled in the U.S. in the last 20 years with more than 1 million cases each year
Trees reduce UV-B exposure by about half; taking twice as long to burn in the shade as in the sun (Grant; Purdue & Heisler; US Forest Service)
Nature’s Sunscreen
Trees help protect against sun in playgrounds and other urban settings esp. on reflective exteriors that reduce heat
Shade Trees on Playgrounds (STOP) Skin Cancer Program, Arkansas Forestry Commission’s Urban and Community Forestry Program
Trees Reduce Stormwater Runoff
Captures water on their leaves and branches.
Reduces peak flow and total volume
Time
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Tree Effects on Runoff
Hydrograph
less treesmore trees
Decrease total runoff volume
Trees Are the Kidneys of the City…filtering water pollutants
Reduces pollutant loading in surface water
Reduces sediment and nutrient levels in water bodies
Reduces erosion near streams and stabilizes banks
The Healing Power of Trees
When viewing trees and green space instead of blank walls, bricks, concrete or bare ground…
REDUCED RECOVERY TIME Surgery patients recovered more quickly and used less pain medication (Roger Ulrich).
REDUCED STRESS Inner city low-income residents in high rise buildings formed stronger social relationships and had less crime (Sullivan and Kuo)
With CITYgreen you can…
Calculate the value of trees in terms of» Stormwater Mitigation» Air Quality Improvement» Water Quality Improvement» Carbon
Storage/Sequestration» Energy Conservation
Model future tree growth
Create and analyze alternate development scenarios
Mecklenburg County, NC
Percentages
1984 Landcover
Mecklenburg County, NC
Percentages
2003 Landcover
20% loss of tree cover and open space
157%increase in impervious surface over 19 yrs.
Air Pollution
Rainfall
Soils
Landcover
Bottom Line
Land Structure + Ecological Analysis Model = Decision Support Material
Urban Ecosystem Analysis Model
Mecklenburg Benefits ChangeCounty
“If brute force or massive amounts of energy don’t work, then you are not using enough of them”
—William McDonough
Why Smart Growth? Why Green Infrastructure?
Charlotte, NC ranked 17th worst in nation for ozone and N02 pollution (American Lung Association)
City’s 2025 Plan encourages more compact urban land use planning and regional transportation planning including mass transit
Smart Growth can integrate green infrastructure into planning
Smart Growth Principles Relating to Green Infrastructure
Preserve Open Space, Farmland, Natural Beauty and Critical Environmental Areas
Strengthen and Direct Development Towards Existing Communities
Take Advantage of Compact Building Design
Foster Distinctive, Attractive Communities with a Strong Sense of Place
Create Walkable Neighborhoods
Make Development Decisions Predictable, Fair and Cost Effective
Encourage Community and Stakeholder Collaboration
Scales of Green Infrastructure Watershed Scale
City, County, Regional/Rural Scale
Neighborhood/Suburban Scale
Site/Urban Scale
#1. Preserve Open Space, Farmland, Natural Beauty and Critical Environmental
Areas
Goal for the Central Carolinas is to connect green infrastructure regionally
Vision Map 2020
Ribbonwalk Nature Preserve
94% tree canopy (179 acres) 5% open space .2% impervious surface
Ribbonwalk’s Woodlands, Wetlands, and Meadows
Features beech trees with 35” diameters
Provides $2.3 million in stormwater runoff value
$35,000 annual air pollution removal value
Ribbonwalk Part of The Irwin Watershed
40% tree canopy (7,800 acres)
20% open space 30% impervious Provides $133 million in
stormwater mgt. value Provides $1.5 million in
annual air pollution mitigation value
Rewrote their zoning ordinance to preserve of large open space areas east and west of town based on ecological criteria
Town of Huntersville, NC Ecosystem Services
$163 million in stormwater runoff savings
$2 million in air pollution mitigation value annually
» 20,000 acres
» 53% tree canopy
» 26% open space
» 11% impervious
Town of Huntersville, NC
Rewrote zoning ordinances to replace auto-centered development with TND’s: pedestrian-oriented, social neighborhoods.
Low Impact Development (LID) in zoning ordinance maintains stormwater on site.
#2. Strengthens and Directs Development Towards Existing Communities
Charlotte’s Southend Redevelopment
» Revitalize Old Industrial Areas
» Increase density within ¼ mile of light rail
Southend Can Become Greener 390 acres 10% tree canopy 72% impervious 12% open space
Southend’s Environmental Benefits
Current Tree Canopy Provides
» $1 million in stormwater value
» $7,400 in annual air quality value
» 5-15% improvement in air quality value
#3.Create Walkable Neighborhoods
South Blvd main thoroughfare redeveloped with light rail and pedestrian access
#4.Take Advantage of Compact Building Design
Huntersville Promotes Denser Development Toward The Interstate & within ¼ mile of planned light rail transit station
Urban open space required within ¼ mile from every residential lot
Birkdale Mixed Use Center
#5. Foster Distinctive, Attractive Communities with a Strong Sense of Place
Myers Park Planned Community (2,200 acres) Designed by John Nolan in 1911
Myers Park Tree Canopy Integral to Character of Community
» 67% tree canopy (1,500 acres)
» 13% open space
» 13% impervious surface
Myers Park Environmental Benefits
$25 million in stormwater runoff management value
$293,000 in air pollution removal benefits
#6. Make Development Decisions Predictable, Fair and Cost Effective
For metropolitan areas east of the Mississippi and in the Pacific Northwest:
Average tree cover counting all zones
40%
Suburban residential zones 50%
Urban residential zones 25%
Central business districts 15%
Set community-wide tree canopy goals
#7. Encourage Community Collaboration
“For those [communities] not immediately facing non-attainment, we will work toward ensuring that poor air quality does not become an issue for you.”
—Joe White, Chairman, Centralina Council of Governments.
Carolina Piedmont Green Initiative supports SEQL
15 counties in North and South Carolina
Integrate air quality, sustainable growth, and water resources affecting the region
Intergovernmental cooperation to tackle common issues
Uses green infrastructure as an asset
Putting Green Infrastructure into Smart Growth
Measure and set regional scale green infrastructure goals
Use green infrastructure tools to test smart growth practices with ecosystem services provided
Implement goals at a local scale-project by project
Time
Ru
nof f
Vo
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Tree Effects on Runoff
Hydrograph
less treesmore trees
Decrease total runoff volume
www.americanforests.org
“The best development intricately links nature with the built environment”. --Sara Gutterman, Green Builder Inc.