Forests

Forests play an important role in the global carbon cycle for their ability to absorb carbon dioxide and store carbon in biomass. In 2005, global forests covered 3,952 M ha, or 30% of the total land area. ¹ the UN Food and Agriculture Organization (FAO) estimates that global forests store 638 Gt of carbon in their ecosystems, as compared to the approximately 750 Gt of carbon stored in the atmosphere. Of this forest carbon, 283 Gt (44%) is stored in forest biomass while the remainder is stored in soil (46%), dead wood (6%) and litter (4%).²

While many temperate forests are slowly growing tropical forests are shrinking at a relatively rapid rate. Annually deforestation removes 13 M ha of forest, or 0.2% of total forest area. ³ In the tropics, forests cover approximately 43% of land area, and deforestation is occurring at an annual rate of approximately 0.6%, for a cumulative loss of 8.3% of tropical forests over the 1990-2005 time period.

Annual emissions and absorptions from land-use change activities, global estimates for the 1990s

Source: Baumert et al.. Author: the same. Permission: unknown.

Deforestation and carbon emissions

While forests serve as a net carbon sink, CO2 emissions from land use change and deforestation account for approximately 20-25% of global anthropogen CO2 emissions ⁴, significantly dampening forests’ role as a carbon sink. Tropical deforestation, driven by agriculture and exploitation of forest resources, dominates these land use change emissions ⁵, as illustrated to the right.

CO2 emissions from deforestation comprise a significant portion of anthropogenic GHG emissions, as illustrated below right.

However, there is much uncertainty regarding the magnitude of land use change emissions due to 1) uncertainty in the estimates of deforestation rates in some regions, and 2) uncertainty in the carbon storage capacity of different forests. Best estimates of emissions from deforestation in the tropics in the 1990s range from 0.9. ⁶ to 2.2GtC/yr. ⁷

While there is high uncertainty associated with the estimates of LUCF emissions, the magnitude of these emissions is such that they are significant, even at low estimates. At the IPCC’s low estimate, LUCF emissions account for 7.5% (0.5 GtC/yr) of anthropogenic emissions, and at its high estimate, LUCF emissions account for 30.4% (2.7 GtC/yr) of emissions.

Deforestation concentrated in few countries

LUCF emissions are not evenly distributed, but are concentrated in a few tropical countries experiencing very high rates of deforestation. Brazil and Indonesia account for approximately 50% of net deforestation ⁸ and 50% of global LUCF CO2 emissions. ⁹ The 15 countries with the highest LUCF CO2 emissions account for almost 90% of net global LUCF CO2 emissions. ¹⁰ With the exception of Mexico, LUCF emissions comprise the majority of their GHG emissions. Indonesia, Brazil, and

Deforestation rates for the 17 countries with the highest annual rates of deforestation

Source: FAO 2006 and Butler 2006. Author: the same. Permission: Public resource.

Malaysia are among the top ten greenhouse gas emitters globally as a result of their high LUCF emissions.

Footnotes

¹: FAO 2006

²Policies to Reduce Emissions from Deforestation and Degradation (redd) in Developing Countries, An examination of the issues facing the incorporation of REDD into market-based climate policies, Erin C. Myers Madeira, December 2008/ FAO 2006

³: FAO 2006; Butler 2007

⁴:WRI; IPCC 2000

⁵:IPCC 2007

⁶:Achard, Eva et al. 2004

⁷:Houghton 2003

⁸:FAO 2006

⁹: WRI; Houghton 2003

¹⁰: WRI; Houghton 2003

Resources

This page was adapted from writing by Erin C Myers Madeira, and originally appeared on the Clean Energy Wiki

Achard, F., H. D. Eva, et al. (2004). "Improved estimates of net carbon emissions from land cover change in the tropics for the 1990s." Global Biogeochemical Cycles 18: 12.

Baumert, K. A., T. Herzog, et al. (2005). Navigating the Numbers: Greenhouse Gas Data and International Climate Policy. Wahington D.C., World Resources institute: 132.

Butler, R. A. (2007). "A World Imperiled: Forces behind forest loss. " Tropical Rainforests: Imperiled Riches—Threatened Rainforests", Retrieved July 12, 2007.

FAO (2006). Global Forest Resources Assessment 2005: Progress towards sustainable forest management. FAO Forestry Paper. Rome, Food and Agriculture Organization of the United Nations: 320.

Houghton, R. A. (2003). Emissions (and Sinks) of Carbon from Land-Use Change. Report to the World Resources Institute from the Woods Hole Research Center. Washingotn DC, Woods Hole Research Center.

IPCC (2000). Land Use, Land-Use Change, and Forestry Special Report of the IPCC. R. Watson, I. Noble, B. Bolinet al. Cambridge, IPCC.

IPCC (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. S. Solomon, D. Qin, M. Manninget al. New York, Intergovernmental Panel on Climate Change: 996.

WRI CAIT: Climate Analysis Indicators Tool, World Resources Institute.

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Forests

Deforestation and carbon emissions

Deforestation concentrated in few countries

Footnotes

Resources