[C] The Hidden Frontier of Forest Degradation - Rainforest Alliance

SUMMARY FOR POLICY & PRACTICE
» Degradation emissions represent at least 20 percent of total tropical forest emissions. This estimate is based on a review of regional estimates
from all three major tropical forest zones (Amazonia, Congo basin, Southeast Asia) which find that degradation emissions represent from 20 to 57
percent of total emissions from deforestation and degradation.
» Degradation emissions appear to represent (i) the majority of emissions from tropical forests in Africa, and (ii) a magnitude similar to deforestation
in tropical Asia.
» Global estimates referenced by the IPCC Assessment Report 4 appear to underestimate emissions from degradation due to technical limitations
of global estimates to date. Work is needed to (i) improve the consistency of methods used to estimate degradation emissions, and (ii)
improve the accuracy of global estimates.
» Degradation often increases the likelihood of deforestation. Thus, including emissions from degradation in a REDD mechanism is important
not only to address direct emissions resulting from degradation, but also to link incentives for mitigation towards the first steps in a chain of events
leading to deforestation.
Estimates of the amount of global emissions from tropical
forest degradation vary by almost an order of magnitude.
Studies referenced by the Intergovernmental Panel on
Climate Change (IPCC) Fourth Assessment Report (Nabuurs
et al., 2007) estimate that forest degradation emissions represent
4.4 percent (Achard et al., 2004) to seven to nine percent
(Houghton, 2003; DeFries et al., 2002) of total tropical forest
carbon emissions. In contrast, a recent study attributes about 35
percent of tropical forest emissions to legal selective logging
alone (0.51 Gt C/yr), in just the 20 percent of tropical forests
identified as “production estate” by the International Tropical
Timber Organization (Putz et al., 2008).
Degradation from Logging
Logging is the only type of forest degradation with global tropical
emissions estimates (Putz et al. 2008, Houghton 2003).
Tropical Asia was identified by Putz et al. (2008) as the
largest source of logging emissions. New methods to detect
selective logging activities (Asner et. al. 2005), and partial
canopy fire (Souza et. al. 2005), have revolutionized the
detection of degradation emissions (Curran et al., 2006);
however these methods have not yet been applied globally.
Asner et al. (2005) determined that emissions from selective
logging in major portions of the Brazilian Amazon add up to
0.08 GtC to the atmosphere each year, increasing the estimated
gross annual anthropogenic flux of carbon from Amazonian
forests by 25 percent over carbon losses from deforestation
(Figure 1). It was also found that annual logging activities
cover an area similar in size to the area deforested each year.
These new analytical methods have thus revealed that selective
logging represents about 20 percent of emissions from
degradation and deforestation in the Amazon region 3 .
FIGURE 1. Spatial distribution of selective logging in five timber-production states of
the Brazilian Amazon for the year intervals 1999 (red), 2000-2001 (blue), and 2001-
2002 (green). The states of Amazonas (AM), Amapa (AP), Tocantins (TO), Maranhao
(MA), and the southern non-forested part of Mato Grosso were not included in the
analysis. Light grey areas show the extent of indigenous reserves; dark grey areas
delineate federal conservation lands as of 1999. RR, Roraima; PA, Pará; MT, Mato
Grosso; RO, Rondônia; AC, Acre. This figure is reproduced, with permission of the
authors, from Asner et. al. 2005.
Degradation from Fuelwood Harvest
It is clear that fire and fuelwood harvest, though not yet
measured globally, represent two other major sources of
degradation emissions. Fuelwood harvesting accounts for 40
percent of global removal of wood from forests according to
the FAO (2006); however, it is not yet clear how to translate
this activity to actual greenhouse gas emissions caused by fuelwood
harvesting. An analysis by Gaston et al. (1998) concluded
3
We arrive at this “about 20 percent” figure simply by adding the Asner et. al. (2005) estimate of selective logging emissions to deforestation emissions. It appears that Asner et.
al.(2005) have accounted for the average annual area logged that is subsequently deforested in generating their 0.08 GtC value (they find that 19% of the total area logged was subsequently
deforested three years later).
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