for Batang Toru and 1,439,499 tCO2/year for Tripa. Real emis-
sions from Tripa are much higher when below-ground carbon would have been included. Most of these emissions were due to the transition from primary forest to disturbed forest in Batang Toru and from the transition from undisturbed forest to oil palm plantations in Tripa.
Land-use transitions from undisturbed forest to other land uses lead to an increase in profitability because the profit- ability of undisturbed forest was set at zero in the current model (i.e. ecosystem services were not valued). If a REDD approach whereby avoided CO2 can be calculated which value CO2
emissions have a value, it should have to offset the
opportunity costs for land use transitions. Because the main aim here is orangutan conservation, the focus is on the tran- sition from undisturbed forest to other land uses. In figure 3, the required price per metric tonne of CO2
economic incentive to avoid past
turbed forest to other land uses is clear. For the transition to the most profitable land-use a price of slightly more than USD 10 per tCO2
Figure 3: Above-ground carbon-stock density changes in the Batang Toru and Tripa study areas.
Therefore, if current trends persist in Tripa, the forests will have disappeared by 2015/2016.
As a consequence, a decrease of above ground carbon stocks was observed over the past 20 years at both sites (Figure 3). In Batang Toru, land use changes and deforestation led to an overall loss of around 10 tonnes of carbon per hectare be- tween 1994 and 2009. Due to its exploitation for the cultiva- tion of oil palm, the peat area of Tripa had to face a much more important decrease of 66 tonnes of carbon per hectare in the time period 1990-2009. In terms of CO2
corresponds to an overall emission per year of 634,903 tCO2
to offer a viable transitions from undis- would have been sufficient to offset opportunity
costs in Batang Toru. For Tripa this value is lower because of the below ground carbon stocks in the peatlands (Figure 4).
ICRAF also considered future options of land management, using models to examine the economic conditions that green- er scenarios would impose. In Tripa, if oil palm exploitation is maintained inside oil palm plantations, but remaining for-
est patches are conserved, a minimum price of 5.2 USD/tCO2 would be needed on the carbon market to offset profit made from a business as usual scenario where such forest patches would be converted to oil palm plantations. Halting the con- version of undisturbed forests in Batang Toru to disturbed forests or agriculture would require a minimum price of USD 11.5 /tCO2
range paid for REDD projects of USD 9.43/tCO2 emissions, it
on the carbon market. These prices are within the to USD 17/tCO2
[with a weighted price average of USD 13.33, data from REDD projects from 1990-2009 (Hamilton et al. 2009)].
Figure 4: Opportunity costs for the transition from forest to other land uses between 1994-2009 in Tripa and 1990-2009 in Batang Toru.