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29

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.