Urban trees and carbon.

While much of the attention to trees and their effect on carbon storage has focused on rural forests, urban forests also have a significant role to play. All cities have a carbon debt. Carbon is a major air pollutant, and air pollution is a costly problem in many urban areas of the United States, contributing to lung, throat, and eye irritation; respiratory and heart disease; and cancer.

AMERICAN FORESTS has conducted an urban ecological analysis of several U.S. cities to assess urban forests' role in removing and storing carbon. Carbon, which accounts for about half the dry weight of most trees, is measured in two ways: storage, or the amount currently stored in tree biomass, and sequestration, the rate of absorption, usually measured annually.

AMERICAN FORESTS' recent findings in Atlanta, Georgia, and in Dade County and Fort Lauderdale, Florida, show that trees provide quantifiable benefits. Using our CITYgreen software program and USDA Forest Service research, AMERICAN FORESTS calculated carbon storage and annual sequestration rates within a defined study area and then projected these rates to the city or region. The value of carbon sequestration was estimated by applying the most current cost figures for emission control to the cost of cleaning air pollution out of the air.

The findings show AMERICAN FORESTS' Urban Ecological Analysis can provide local governments and environmental organizations with information needed to guide local planning and create action programs that lead to more sustainable communities. Sustainable communities co-exist with and benefit from the functions of the natural environment. Dade County, for example, is involved in several related environmental improvement programs. The information gathered will be valuable in calculating carbon sequestration and energy conservation for planning and cost/benefits analyses.