most acute situation is in the Tripa swamps. If current trends continue in Tripa, huge amounts of carbon that have slowly ac- cumulated in these peatlands over many thousands of years will be irreversibly released back into the atmosphere in just a few decades. Tis is a serious concern for climate change mitigation and it is important to determine whether the value of avoided carbon emissions could offset opportunity costs to other land uses. For the focus areas (Batang Toru and Tripa) in the two main orangutan habitats (forest on non-peatlands and peat) it was calculated what the values (USD/ha) would be of the avoided CO2
emissions over a period of 25 years (Figure 4). For
Batang Toru these ranged from 3,711-11,185 USD/ha and for Tripa from 7,420-22,094 USD/ha (Figure 4).
Figure 4: Value for the avoided CO2
emissions during a 25-year
transition period from primary forest to oil palm plantations or other land uses for Batang Toru and Tripa. Net present values (NPV) per hectare were calculated using the model in Butler et al. (2009) with the following prices (range per tCO2
9.43-17, Hamilton et al. 2009). Calculations were made under a scenario where carbon prices remained constant during 25 years or appreciated 5% annually during that period). Carbon values were calculated with an equal allocation model for 25 years (Butler et al. 2009) at a 6.5% discount rate. Carbon stock in agricultural land uses was not included. Above-ground car- bon assessment came from the ICRAF rapid assessment re- port (Tata and van Noordwĳk 2010) for Tripa (forest on peat) and Batang Toru (forest on non-peat). Values for the loss of carbon in peatlands during the transition from primary for- est were from Murdiyarso et al. (2010) for such transitions in Central Kalimantan. For the Batang Toru, no below-ground carbon losses were included due to a lack of data. Thus the Batang Toru values are conservative estimates. Development and management costs of a REDD project are included in the model and follow the standards of the World Bank’s Forest Carbon Partnership Facility (Butler et al. 2009). Loss of carbon sequestration by forests has not been included in the model nor that of carbon accumulation in soil and peat.
A small forest stream in Batang Toru (Perry van Duĳnhoven)