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Cities Deserve Green Spaces!

21. Urban Tree Canopy (60% Goal)

Why Urban Trees?
  • Cooling: Trees reduce "heat island effect" (cities 5-10°F hotter than rural areas)
    • Shade, evapotranspiration
    • Saves: Air conditioning costs, heat-related deaths
  • Air Quality: Trees filter pollutants (PM2.5, ozone, NOx)
    • Health: Reduces asthma, respiratory disease
  • Stormwater: Tree roots absorb runoff (prevent flooding)
  • Mental Health: Access to trees = reduced stress, depression, and anxiety
  • Carbon: Urban trees store carbon

Current Status:

  • U.S. Urban Tree Canopy: Averages 27%
  • Varies Widely:
    • Portland, Seattle: 30-35%
    • Phoenix, Las Vegas: <10%
    • New York, Chicago: 20-25%

Goal: 40% Urban Tree Canopy (All Cities)

Implementation:

A. Plant 500 Million Trees (10 Years):

  • 50 Million Trees/year in cities
  • Priority:
    • Low-income neighborhoods (currently 15% less tree cover than wealthy areas)
    • Heat islands (industrial areas, parking lots)
    • Near schools, hospitals, and elderly housing

B. Species Selection:

  • Native Trees: Oak, maple, sycamore, and elm (region-appropriate)
  • Climate-Adapted: Trees that tolerate heat, drought, and pests
  • Diversity: Plant 20+ species (prevent disease wipes out all trees)
  • Fruit/nut trees: Edible landscaping (food security)

C. Maintenance:

  • Problem: 30% of urban trees die within 5 years (lack of care)
  • Solution:
    • Tree Stewards: 10,000 workers watering, mulching, and pruning young trees
    • Community Involvement: Residents adopt trees on their block
    • Adequate Water: Drip irrigation for first 3 years

D. Parking Lot Greening:

  • Mandate: All parking lots >50 spaces = 30% tree cover
    • Shade reduces car interior temperatures (less AC), stormwater runoff
  • Retrofit: 100,000 existing parking lots

E. Street Tree Programs:

  • Plant Street Trees: Every residential street = trees every 30 feet (both sides)
  • Infrastructure: Tree wells, permeable pavement (so roots get water)

F. Green Roofs/Walls:

  • Green Roofs: Vegetation on flat roofs (cooling, stormwater, habitat)
    • Mandate: All new buildings >10,000 sq ft = green roof
  • Green Walls: Vertical gardens on building facades
    • Cooling, air quality, aesthetics

Employment:

  • Tree Planters: 20,000 workers planting trees
  • Tree sSewards: 10,000 workers maintaining trees (3-5 years per tree)
  • Arborists: 5,000 professionals managing urban forests
  • Green Infrastructure: 10,000 workers installing green roofs/walls

Cost: $25 billion (10 years) = $2.5B/year

  • Per tree: $500 (sapling, planting, 3 years maintenance)
Results:
  • 500 Million Trees Planted
  • 40% Urban Tree Canopy (from 27%)
  • Cooling: Urban temperatures reduced 3-5°F
  • Health: 50,000 fewer asthma cases/year, 1,000 fewer heat deaths/year
  • Stormwater: 5 billion gallons/year runoff absorbed
  • Carbon: 150 million tons CO2 sequestered (over tree lifetimes)

22. Daylighting Buried Streams (Urban River Restoration)

What is Daylighting?
  • Unbury Streams: Many urban streams were buried in pipes/culverts (1900s)
  • Daylighting: Excavate and expose the stream to daylight, and restore the natural channel
Why?
  • Flood Control: Natural streams absorb water better than pipes
    • Pipes overwhelmed → flooding
    • Open streams → floodplains absorb overflow
  • Habitat: Fish, amphibians, insects return
  • Recreation: Urban parks with streams (walking paths, fishing)
  • Water Quality: Natural filtration (vs. pipes dumping directly to rivers)
  • Heat Reduction: Water cools urban areas (evaporative cooling)

Examples (Already Done):

  • Seoul, South Korea (Cheonggyecheon Stream): 3.6 miles daylighted (2005)
    • Result: Temperatures dropped 5°F, biodiversity returned, became tourist attraction
  • Yonkers, NY (Saw Mill River): 0.25 miles daylighted (2012)
    • Parking lot removed, stream restored, and flood risk reduced
  • Berkeley, CA (Strawberry Creek): Portions daylighted on UC Berkeley campus

U.S. Implementation:

Target: 1,000 stream daylighting projects (10 years)

Priority Cities:

  • Los Angeles: LA River (50 miles buried in concrete)
    • Daylighting portions: 10 miles (pilot)
    • Result: Wildlife corridors, flood control, and recreation
  • Boston: Stony Brook, Mill Creek (multiple streams buried)
  • Philadelphia: Cobbs Creek, Wingohocking Creek
  • Detroit: Multiple streams buried under parking lots (daylighting = green space)
  • San Francisco: Mission Creek, Islais Creek
Process:

1. Assessment:

  • Identify Buried streams: Old maps, storm drain surveys
  • Feasibility: Can we excavate? (not always possible under buildings)

2. Community Input:

  • Public Meetings: Residents design stream parks
  • Environmental Justice: Prioritize low-income neighborhoods (need green space)

3. Excavation:

  • Remove Pavement and Pipes
  • Dig Natural Channel: Meandering, varied depths (habitat diversity)

4. Revegetation:

  • Native Plants: Willows, sedges, and rushes (stabilize banks)
  • Trees: Shade keeps water cool (fish need cold water)

5. Park Development:

  • Trails, Benches, Fishing Access
  • Interpretive Signs: Education about urban ecology

6. Stormwater Integration:

  • Green Infrastructure: Bioswales drain to stream
  • Reduces CSO (Combined Sewer Overflows): Less sewage overflow during storms
Co-Benefits:

Property Values:

  • Daylighted Streams Increase Nearby Property Values 5-15%
  • Gentrification Risk: Must pair with affordable housing protections

Public Health:

  • Access to Nature: Reduces stress and increases physical activity
  • Cooling: Water features reduce heat

Biodiversity:

  • Urban Wildlife Corridors: Streams connect parks and forests
  • Salmon Restoration: Pacific Northwest cities (Seattle, Portland) = salmon return to urban streams
Employment:
  • Excavation Crews: 5,000 workers removing pavement and digging channels
  • Restoration Ecologists: 1,000 designing and monitoring projects
  • Park Maintenance: 2,000 workers maintaining stream parks

Cost: $10 billion (10 years) = $1B/year

  • $10 million per Mile (excavation, restoration, and park development)
Results:
  • 1,000 Miles of Streams Daylighted
  • Flood Risk Reduction: 20% reduction in urban flooding (cities with projects)
  • Recreation: 10 million people gain access to stream parks
  • Biodiversity: Fish, amphibians, and insects return to 1,000 urban waterways