A new data analysis undertaken by Dr Susan Page of the University of Leicester Department of Geography and colleagues involved in the EU-funded CARBOPEAT and RESTORPEAT projects shows conclusively that large amounts of carbon dioxide are released from peatland in Southeast Asia when it is converted from natural swamp forest to plantations of oil palm or pulpwood trees.
This supports the findings of a recent Greenpeace report on the impact of growing oil palm on tropical peatlands and a feature article on palm oil and pulpwood plantations in this week's New Scientist.
According to Professor Jack Rieley of the School of Geography, University of Nottingham these new life cycle analysis calculations show that all forms of land use change on tropical peatland lead to massive losses of carbon from the peat store and the transfer of large amounts of CO2e to the atmosphere contributing to climate change processes. The worst land use scenario is degraded peatland. This is peatland that has been deforested and drained but is not currently managed; these degraded peatlands are susceptible to fire in every dry season which leads to large carbon emissions. Plantations of oil palm and acacia trees grown for pulpwood, however, also lose large amounts of carbon (see table) owing to rapid decomposition of the peat carbon store as a result of oxidation caused by deep land drainage.
Natural peat swamp forest acts as a carbon sink accumulating at least 2.6 t ha-1 CO2e yr-1 as a consequence of tree growth and peat accumulation. Peatland under plantation agriculture and degraded peatland are both major carbon sources with oil palm and pulpwood plantations emitting CO2 e in the order of 170 and 280 t ha-1 yr-1, respectively, equivalent to 1,000 and 1,900 t ha-1 yr-1 over the 25 year life cycle.
Since the areas occupied by oil palm plantations on peatland in Malaysia and Indonesia are huge, in the order of 420,000 hectares for the former and 2,800,000 ha for the latter, the combined 25 year life cycle CO2e emissions are enormous and in the region of 3,220 Mt CO2e.
According to Professor Florian Siegert of Ludwig-Maximilians-University, Munich, Germany, who is studying land cover change in Southeast Asia, the large increase in area of oil palm projected to take place in coming years to satisfy the biofuels market will release much more CO2 emissions than the fossil fuel it is supposed to replace (up to 30 times more depending upon management of individual plantations). The emissions associated with palm oil plantations growing on thick tropical peat are particularly massive. In Indonesia it is estimated that producing 1 tonne of palm oil on peatland will cause emissions of between 15 and 70 tonnes of CO2 over the life cycle of 25 years as a result of forest conversion, peat decomposition and emission from fires associated with land clearance. The range of emission values is so large because oil palm fruit harvest can be much lower on nutrient poor and poorly drained peat soils. Peat swamp forests are the only major land area not yet developed in Southeast Asia, but increased demand for palm oil and pulp for paper is already leading to accelerated conversion of peat swamp forests into plantations.
This new assessment of the impact of plantations on CO2e emissions from tropical peatland is very important, especially in view of the upcoming UNFCCC climate change conference that will be held in Bali, Indonesia from this week (4-14 December). Delegates to the Bali COP will discuss proposals to improve international requirements for reduced greenhouse gas (GHG) emissions under the Kyoto Protocol. Up until quite recently most attention was focused on GHG emissions from industry and the burning of fossils fuels. There is now an enhanced emphasis on emissions from non-industrial sources, such as deforestation, agricultural practices and, in the case of Southeast Asia, peat swamp reclamation. Various mechanisms to reduce emissions from deforestation have been proposed to UNFCCC and will be discussed during the Bali meeting.
Dr Susan Page said: 'Current land use and land practise developments in Southeast Asia give grave cause for concern. While deforestation rates in non-peatland areas are decreasing slightly owing to depletion of forest resources, those on peatlands have been rising for the last 20 years. In 2005, 25% of all deforestation in Southeast Asia was on peatlands owing to demand for land on which to establish plantations. Current UNFCCC negotiations in Bali on reduced emissions from deforestation and degradation (REDD) could offer a crucial opportunity to reduce carbon emissions from tropical peatlands and thus contribute to combating global climate change.'
Time for action: Dr Page went on to say that 'The Government of Indonesia should regard its peatlands as a 'bank' because they are worth more as biodiversity and carbon stores than oil palm or pulp tree plantations. As a first step it should rescind ALL concession licenses that have been (and still are being) granted for new plantations on its peatland, especially those granted by the decentralised local governments without carrying out Environmental Impact Assessments. It is clear with current rates of peatland conversion that the Indonesian Government cannot reduce its massive non-industrial CO2 emissions unless it stops plantation and other agricultural and industrial uses of its peatlands, and takes serious measures to protect the natural resource functions of biodiversity, carbon and water stores of the remaining peat swamp forests.'