The Natural Fix?

Great quantities of carbon are currently being lost from drained peatlands and unless urgent action is taken this loss will in- crease further as the area of drained peatlands is steadily in- creasing. At least half of these losses are currently happening in tropical peatlands. In these areas, which are concentrated in Malaysia and Indonesia, large areas of tropical forest are being drained for palm oil and pulpwood production (Verwer et al. 2008). Drainage of peat soils produces an aerobic environment in which peat carbon is respired by soil organisms. Carbon losses are further exacerbated by the increased likelihood of fire outbreak on drained peatlands, with drained peat acting as a fuel source for underground fires.

ability losses are already significant (0.5–0.8 Gt C per year) and a significant fraction of overall anthropogenic emissions of green- house gasses. Because of these losses, biofuels grown on drained peat soils have a negative impact on the global carbon balance. It is estimated for instance that combustion of palm oil produced on drained peatland generates per unit energy produced 3–9 times the amount of CO 2 produced by burning coal, equating to a carbon debt requiring 420 years of biofuel production to repay (Fargione et al. 2008). Such a figure highlights the false carbon economy of cultivating biofuels on drained peatland, the need to conserve pristine peatlands and highlights the potential for emis- sion reduction by rewetting. Rewetting of peatlands restores them to their waterlogged state, re-imposing the anaerobic conditions in which the decomposition of dead plant material is halted, greatly reducing the release of CO 2 and the risk of fire outbreaks.

There is uncertainty over the degree of carbon losses from drained peatlands (Parish et al. 2008; Verwer et al. 2008) but in all prob-

Peat distribution in the World

Global peatland area by country (in percentage)

0 or no data less than 0.5 0.5 to 2.0

5.0 to 10.0 2.0 to 5.0 more than 10.0

Source: Parish et al., 2008.

29