U.S. Urban Forest Statistics

David J. NowakUS Forest Service

Syracuse, NY

Year Urban (48)

1990 47.3 (2.5%)

2000 58.6 (3.1%)

2010 67.8 (3.6%)

~VT+NH

~NJ+MA

1) Past urban land increase (1990-2010): +1 million acres/year > 2,700 acres / day

Million Acres

Delaware land area = 1.2 million acres

Urban / community land (2010) = 138 million acres (50 states)

Urban (2010)

Most Urbanized States

%Urban %UC Acres Urban Acres UC

NJ 39.8 NJ 45.8 TX 5.6M AK 16.3MRI 38.7 RI 43.2 CA 5.3M CA 9.9MMA 38.0 CT 42.9 FL 4.8M TX 9.3MCT 37.7 MA 41.5 GA 3.1M FL 7.1MDE 20.9 MD 27.4 PA 3.0M AZ 5.6M

MN 2.2 (31)MN 5.8 (28)MN 1.1M (25) MN 2.9M (17)

Urban Growth Pattern (1990-2000)

Urban Growth Pattern (2000-2010)

Average Growth Pattern (1990-2010)

2) Projected urban land increase (2010-2060): +2 million acres/year

Urban land (conterminous U.S.)2010 = 67.8 million acres (3.6%)2060 = 165.1 million acres (8.7%)Increase greater than size of Montana

Urban (1990)

Urban (2000)

Urban (2010)

Urban (2020)

Urban (2030)

Urban (2040)

Urban (2050)

Urban (2060)

Growth in Percent Urban (2010 – 2060)

3) % Urban Tree Cover > % Rural Tree CoverPercent Tree Cover

State State Urban RuralConnecticut 72.6 66.5 75.9Massachusetts 70.8 64.5 74.4New Hampshire 88.9 64.0 91.5Maine 83.1 54.0 84.4Rhode Island 70.3 54.0 82.0Alabama 70.0 53.0 71.5Vermont 81.5 53.0 82.3Georgia 66.4 52.0 67.7New Jersey 57.0 50.4 59.8North Carolina 62.6 48.2 63.9

Idaho 37.9 13.0 38.2New Mexico 19.1 12.0 19.2Nevada 11.6 12.0 11.6Montana 27.5 9.0 27.4Wyoming 14.5 9.0 14.4US(48) 34.2 35.0 34.1

Nowak and Greenfield, 2012. Tree and impervious cover in the United States. Landscape and Urban Planning 107: 21-30.

23.7 million acres of urban tree cover in US

Difference – Urban vs. Rural Tree Cover

4) Residential and Vacant / Open Space:~ 75% of Urban Tree Cover

Percent of Total Tree Cover in Cities by Land Use

Forest(40% TC)

Grass(20% TC)

Desert(10% TC)

5) Billions of Trees = Trillions of $Number of urban trees = 4.9 billion

15 trees per person

Asset / structural value = $4.1 trillion$12,900 per person

Above ground d.w. biomass = 1.3 billion tonsWaste wood (2% mortality) = 26 million tons

6) Leaves are ImportantTotal leaf area = 176,000 sq. miles (> CA)Total leaf biomass = 39 million tons

22.9 million t C715,000 t N310,000 t K67,000 t P

7) Carbon EffectUS urban forests

704 million tons of carbon stored ($50.5 billion)28 million tons of carbon sequestered per year ($2 billion/year)

Nowak, D.J., E.J. Greenfield, R. Hoehn, and E. LaPoint. 2013. Carbon storage and sequestration by trees in urban and community areas of the United States. Environmental Pollution. 178: 229-236.

Urban Storage and Sequestration (tonnes)

Rate = kg/m2 tree cover per yearStorage = $50.5 billion; Sequestration = $ 2 billion/yr

8) Air Pollution Removal and Health EffectsU.S. urban forests

717,000 tons/year ($4.7 billion/year)Impact, reduction in incidences of:

~580 deaths / year~580 emergency room visits / year~330,000 asthma exacerbations / year~485,000 acute respiratory symptoms / year

Nowak, D.J. S. Hirabayashi, E. Ellis and E.J. Greenfield. 2014. Tree and forest effects on air quality and human health in the United States. Environmental Pollution 193:119-129

Annual Pollution Removal Distribution

9) National Building Energy Conservation36 million MWh energy production avoided annually ($4.3 billion)228 million MBTU energy production avoided annually ($2.9 billion)Pollutant Tonnes avoided/year $ millions/year

Carbon dioxide 19,800,000 425

Carbon monoxide 16,200 26

Course PM 1,720 97

Fine PM 4,190 590

Methane 459 0.2

Nitrogen oxides 17,100 161

Sulfur dioxide 45,300 405

VOCs 1,100 1

Total 1,705

Preliminary results

State Energy SavingsState Saving ($ millions/yr)

Texas 808

Florida 642

Illinois 441

California 361

New York 348

South Dakota 27

New Mexico 22

Vermont 18

Idaho 16

Wyoming 13

US(48) 7,217

10) U.S. Urban Forest Annual ValuesAvoided energy use = $7.2 billionAir pollution removal = $4.7 billionCarbon sequestration = $2.0 billionAvoided emissions = $1.7 billionTotal = $15.6 billion

$760 per acre of tree cover

Current carbon storage value = $50.5 billion

Thank You

dnowak@fs.fed.us nrs.fs.fed.us/units/urban