Virginia Forests and Climate Change

Forest trees use the photosynthesis process to remove CO2 from
the air and store the carbon in trees, understory vegetation, the forest floor
and in the soil.

The world’s forests, including the forests of Virginia, play a large, positive role in the climate change issue.

Forest trees use the photosynthesis process to remove CO₂ from the air and store the carbon in trees, understory vegetation, the forest floor and in the soil. This role of carbon removal, or sequestration, makes the forest a type of carbon sink by absorbing more CO₂ than is emitted. This absorption partially offsets the contribution of carbon to the atmosphere from carbon sources such as the burning of fossil fuels.

Reports estimate that forest tree growth in Virginia sequesters 6.42 million metric tons of carbon each year (the equivalent of 23.54 million metric tons of CO₂). A DEQ report estimates Virginia’s contribution to carbon sources at 120 million metric tons of CO₂. Thus Virginia forests offset nearly 20% of Virginia’s CO₂ emissions.

DEQ report Virginia Emissions: 120 million metric tons of CO2 in 2001
120 MMT CO2 x 12/44 = 32.727 MMTC (million metric tons carbon)
From Birdsey & Lewis Forest Sequestration (English; Word format) 6.42 MMTC/year for 1992-1997
6.42 MMTC / 32.727 MMTC = 19.6 %
current forest stock is about 1.2 billion metric tons of carbon (about 37 years of Virginia emissions)
about 1 MMTC of Carbon is emitted due to forest land conversion each year (about 3% of emissions)

Carbon sequestration provided by trees is a positive aspect of the forest's role in climate change. Two other factors to consider are land use conversion and the fate of forest products.

Since forests serve as large stores of carbon, converting forests to other land use makes an immediate contribution to CO₂ emissions as the land is cleared, debris is burned and soil is removed or disturbed. It is estimated that the loss of forest and land to agricultural or urban uses contributes about 3% of Virginia’s CO₂ emissions each year.

When trees are harvested and made into forest products the carbon in the wood or paper does not immediately return to the atmosphere. In this way, our houses, furniture and even paper (especially when buried in landfills) serve as a carbon sink.

Ways to Enhance the Positive Role of Forests in Climate Change

Conservation of Forest Land – maintaining land in forest cover maintains the carbon sink and prevents the CO₂ emissions that occur during land conversion or development.
Afforestation and Reforestation - planting trees on marginal agricultural land increases carbon sequestration at a rapid rate as the young trees grow quickly and fallen leaves build up on the forest floor. Reforestation of poorly stocked forest stands can also increase carbon sequestration in existing forests.
Forest Management – forests can be managed to increase growth rates and thereby the stock of stored carbon. Thinning and fertilization are some practices that can increase growth.
Biofuels – forests can play a role as a renewable energy source. Since the carbon in word is taken from the atmosphere rather than fossil fuels, burning word, or producing ethanol from wood, results in much lower net CO₂ emissions.

Forests and the Market for Carbon Credits

Carbon credits have been established to reduce CO₂ emissions. By purchasing carbon credits, entities can offset their CO₂ emissions with the activities of others, such as planting trees or conserving forests. This purchase may allow forest owners to gain financially from their contribution to the forest carbon sink. Prices for carbon credits on the Chicago Climate Exchange have ranged from $1-$5 per metric ton of CO₂ equivalent in the past year.

Additional information

US Forest Service Northern Global Change Research Program

NASA Earth Observatory Human Activities Increasing Carbon Sequestration In Forests

Last modified 2007-11-29