US Urban Trees Store Carbon, Provide Billions in Economic Value

Submitted: The Two Sides Team May 10, 2012

From New York Citys Central Park to Golden Gate Park in San Francisco, Americas urban forests store an estimated 708 million tons of carbon, an environmental service with an estimated value of $50 billion, according to a recent U.S. Forest Service study.
7 May 2012

From New York Citys Central Park to Golden Gate
Park in San Francisco, Americas urban forests store an estimated 708
million tons of carbon, an environmental service with an estimated
value of $50 billion, according to a recent U.S. Forest Service study.

Annual net carbon uptake by these trees is estimated at 21 million tons and $1.5 billion in economic benefit.

In the study
published recently in the journal Environmental Pollution, Dave Nowak, a
research forester with the U.S. Forest Services Northern Research
Station, and his colleagues used urban tree field data from 28 cities
and six states and national tree cover data to estimate total carbon
storage in the nations urban areas.

With expanding urbanization, city trees and forests are becoming
increasingly important to sustain the health and well-being of our
environment and our communities, said U.S. Forest Service Chief Tom
Tidwell. Carbon storage is just one of the many benefits provided by
the hardest working trees in America. I hope this study will encourage
people to look at their neighborhood trees a little differently, and
start thinking about ways they can help care for their own urban
forests.

Tens of thousands of people volunteered to plant and care for trees
for Earth Day and Arbor Day this year, but there are opportunities all
year long. To learn about volunteer opportunities near your home, visit
the Arbor Day Foundation.

The Forest Service partners with organizations like the Arbor Day
Foundation and participates in programs like Tree City USA to recognize
and inspire cities in their efforts to improve their urban forests.
Additionally the Forest Service is active in more than 7,000
communities across the U.S., helping them to better plan and manage
their urban forests.

Nationally, carbon storage by trees in forestlands was estimated at
22.3 billion tons in a 2008 Forest Service study; additional carbon
storage by urban trees bumps that to an estimated 22.7 billion tons.

Carbon storage and sequestration rates vary among states based on the
amount of urban tree cover and growing conditions. States in forested
regions typically have the highest percentage of urban tree cover.
States with the greatest amount of carbon stored by trees in urban
areas are Texas (49.8 million tons), Florida (47.3 million tons),
Georgia (42.4 million tons), Massachusetts (39.6 million tons) and
North Carolina (37.5 million tons).

The total amount of carbon stored and sequestered in urban areas
could increase in the future as urban land expands. Urban areas in the
continental U.S. increased from 2.5 percent of land area in 1990 to 3.1
percent in 2000, an increase equivalent to the area of Vermont and New
Hampshire combined. If that growth pattern continues, U.S. urban land
could expand by an area greater than the state of Montana by 2050.

The study is not the first to estimate carbon storage and
sequestration by U.S. urban forests, however it provides more refined
statistical analyses for national carbon estimates that can be used to
assess the actual and potential role of urban forests in reducing
atmospheric carbon dioxide.

More urbanization does not necessarily translate to more urban
trees. Last year, Nowak and Eric Greenfield, a forester with the
Northern Research Station and another study co-author, found that urban
tree cover is declining nationwide at a rate of about 20,000 acres per
year, or 4 million trees per year.

Carbon Storage by Urban Trees

State	Carbon Stored (tons)
Texas	49,800,000
Florida	47,300,000
Georgia	42,400,000
Massachusetts	39,600,000
North Carolina	37,500,000
New York	35,400,000
California	34,600,000
Pennsylvania	31,700,000
New Jersey	30,900,000
Connecticut	25,700,000
Ohio	25,300,000
Michigan	25,200,000
Tennessee	20,800,000
Alabama	20,600,000
Illinois	20,600,000
South Carolina	19,100,000
Virginia	18,300,000
Washington	15,200,000
Maryland	13,100,000
Missouri	12,400,000
Louisiana	11,600,000
Indiana	10,700,000
Wisconsin	10,400,000
Minnesota	10,200,000
Oregon	8,900,000
Arkansas	8,500,000
Mississippi	8,200,000
New Hampshire	7,900,000
Kentucky	7,100,000
Arizona	6,000,000
West Virginia	5,700,000
Kansas	5,300,000
Colorado	4,800,000
Oklahoma	4,800,000
Rhode Island	4,600,000
Maine	4,200,000
Iowa	4,100,000
Delaware	2,500,000
Hawaii	2,400,000
Utah	2,300,000
Alaska	2,200,000
New Mexico	2,000,000
Nebraska	1,800,000
Vermont	1,700,000
Nevada	1,400,000
Idaho	1,200,000
South Dakota	800,000
Montana	500,000
North Dakota	500,000
Wyoming	300,000
Total	708,100,000

The mission of the U.S. Forest Service is to sustain the health,
diversity, and productivity of the nations forests and grasslands to
meet the needs of present and future generations. The agency has either
a direct or indirect role in stewardship of about 80 percent of our
nations forests; 850 million acres including 100 million acres of
urban forests where most Americans live. The mission of the Forest
Services Northern Research Station is to improve peoples lives and
help sustain the natural resources in the Northeast and Midwest through
leading-edge science and effective information delivery.

USDA has made a concerted effort to deliver results for the American
people, even as USDA implements sequestration the across-the-board
budget reductions mandated under terms of the Budget Control Act. USDA
has already undertaken historic efforts since 2009 to save more than
$828 million in taxpayer funds through targeted, common-sense budget
reductions. These reductions have put USDA in a better position to carry
out its mission, while implementing sequester budget reductions in a
fair manner that causes as little disruption as possible.