Forestry
Afforestation is the planting of trees in areas where there was previously no forest. Reforestation is the replanting of trees where deforestation, loss of natural vegetation, has occurred. Anti-deforestation refers to the practice of avoiding deforestation to mitigate carbon emissions. Deforestation is estimated to cause around one-quarter of all anthropogenic carbon emissions (Kindermann et al, 2008). These three methods help reduce carbon dioxide (CO2) concentration in the atmosphere by increasing the amount of vegetation, which will ultimately take up some CO2, as shown by the image below.
Image retrieved from
Advantages:
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Planting trees on low quality (marginal) lands helps maintain soil quality and prevent erosion, as the tree’s root system locks the soil in place.
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Planting trees on marginal lands will significantly increase and maintain biodiversity as the forest will provide a more complex habitat that can support a variety of animals.
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Anti-deforestation prevents negative effects from deforestation such as reductions in biodiversity, disturbed water regulation, and destruction of livelihood for many of the poor (Williams, 2003).
Disadvantages:
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The main liability issue of forestry projects is permanence (i.e., how to issue carbon credit in the event of forest fire). This issue can be addressed by waiting until the original stock is replaced in the carbon trading policy to count any sequestration after casualty for carbon credit (Ruddell et al, 2006).
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Negative impacts of anti-deforestation include decreased expansion of agriculture in tropical areas where slash and burn techniques are used and reduced production of lumber and forestry products.
Potential Storage Sites:
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Afforestation and reforestation projects are most efficient in areas where land rent is cheap, because land rent is one of the main costs for forestry projects. Taking the land rent into account, the best types of land for forestry projects are marginal agriculture land, abandoned cropland, and degraded pastures.
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Globally speaking, developing countries in the tropical region are best suited for afforestation and reforestation projects since those countries generally have low land rent and large areas of deforested land.
Capacity Estimates:
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The average carbon stock (how much carbon can be stored in forest) for managed forest across all tropical regions of the world is generally above 90 metric tonnes of carbon per hectare (van Noordwijk et al, 2005).
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The area of land suitable for reforestation/afforestation in the humid tropics is estimated to range from 300 million hectares to 1 billion hectares (van Noordwijk et al, 2005). Thus the capacity for carbon sequestration by reforestation and afforestation in the humid tropics alone would be 27-90 billion tonnes.
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However, the actual amount of carbon that can be sequestered is dependent upon the carbon price because land owners want to maximize profits. Simulations based upon a range of carbon price models show that the amount of carbon sequestered by afforestation and reforestation in the next 100 years ranges from 60 to 140 billion tonnes globally (Sohngen et al, 2004; Nilsson et al, 1995).
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Protecting 130 million hectares of land from deforestation in the Amazon has the potential to reduce global emissions by 62 Gt of CO2 over the next 50 years (Soares-Filho et al, 2006).
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Anti-deforestation is estimated to reduce emissions by between 1.6 and 4.7 Gt of CO2 per year, depending on the CO2 price in cap and trade systems (Kindermann et al, 2008).
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Reducing deforestation by 10% globally between 2005 and 2030 would reduce emissions by 0.3 – 0.6 Gt of CO2 per year. Reducing deforestation by 50% in the same time period would reduce emissions by 1.5 – 2.7 gigatons of CO2 per year (Kindermann et al, 2008).
Cost Estimates:
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The cost of afforestation and reforestation programs depends on the opportunity cost of the land available for reforestation.
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Initial cost of carbon sequestration through reforestation could be as little as $2 per metric ton of CO2 in United States (Ruddell, S., Walsh, MJ., and Kanakasabai, M., 2006).
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Globally speaking, over the next 100 years, afforestation and reforestation programs can sequester 74 billion metric tons of carbon at an average carbon price of $100 per metric tonne of carbon (Sohngen, B, & Sedjo, R., 2004).
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Financing a 10% reduction in deforestation would require a cost of $2-5 per tonne of CO2 and a 50% reduction would require a cost of $10-21 per metric tonne (Kindermann et al., 2008).
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Reducing deforestation by 10% between 2005 and 2030 would cost $0.4 billion to $1.7 billion annually (Kindermann et al., 2008).
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Reducing deforestation by 50% worldwide between 2005 and 2030 would cost $17.2 billion to $28.0 billion annually (Kindermann et al., 2008).
Readiness:
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Afforestation, anti-deforestation, and reforestation can all be implemented immediately.