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