The peatlands of Indonesia are an increasingly important land resource for the livelihood of the people and for economic development, but they turn rapidly into a carbon source when the peat forests are cleared and drained. Therefore, strategies are needed for the sustainable management of the peatlands and to reduce greenhouse gas emissions. This research was conducted on 464 642 ha of peatland varying in depth between 200 and 680 cm, in the districts of Kubu Raya and Pontianak, in the West Kalimantan province of Indonesia. It was aimed at: (i) evaluating land use changes in the peatland of the two districts and assessing the CO2 emissions these entail; and (ii) recommending options for mitigation of the CO2 emissions. Satellite images in the years 1986, 2002 and 2008 were used for the evaluation of land use changes. This was followed by ground-truthing of recent land cover in 2009. Interviews were conducted with stakeholders to develop emission reduction strategies. The results show that the peatlands were used for various purposes, including the traditional slash-and-burn agriculture for maize, pineapple plantations, intensive vegetable farming, and rubber and oil palm plantations. The peat forest area decreased by 16% from 393 000 ha in 1986 to 329 390 ha in 2008, while shrubland increased by 153% from 9427 ha to 23 814 ha over the same period of time. Oil palm plantations and paddy fields also increased rapidly in expansion. The main sources of emissions were from peat burning, especially for the slash-and-burn farming, peat decomposition due to drainage, and the loss of biomass depending on the land use trajectories. Emission reduction can be achieved through various scenarios. Scenario I, confining future agricultural land development to peatland with peat of <3 m thick, is expected to reduce by 6.8 +/- 2.9% the 2010 to 2035 cumulative CO2 emissions from the 127 million tonnes 'business as usual' (BAU) level. Scenario II, providing fertiliser subsidy to replace the traditional burning technique in addition to Scenario I, is expected to reduce emissions by as much as 11.5 +/- 4.9%. Scenario III, switching future agricultural expansion to mineral soils, is expected to lower the cumulative emissions by as much as 20.5 +/- 8.8%. These scenarios form the basis for sustainable peatland management and for a state of preparedness to reduce emissions from peatland.
