However, information on a directly proportional relationship between peatland
utilization and CO 2 emission in tropical peatlands is still insufficient. Kumar and
Imam (2013) noted that CO 2 is produced by fossil fuel consumption, deforestation,
and degradation of biomass sources, resulting in the oxidation of carbon compounds
in peat and forests.
15.2.2 Methane (CH 4 ) Emission
Methane (CH 4 ) is the second GHG after CO 2 in terms of atmospheric concentration
and emission frequency, but 25 times more in global warming potential (GWP)
(Hooijer et al. 2010). CH 4 is a powerful GHG and has a significant influence on the
earth’s climate. It has an important role in the formation of O 3 and influences climate
parameters (Kumar and Imam 2013). CH 4 emission from peatlands (either drained or
undrained) are modest in comparison with CO 2 emission (Couwenberg et al. 2009;
Hooijer et al. 2010). In the event of peat fires, CH 4 is produced in addition to CO 2
and CO. Methane emission also occur due to changes in the process of
methanogenesis that occur due to changes in land use and land cover on peatlands
as well as peat drainage.
Decreasing water level after drainage can reduce methanogenesis but increase
methanotroph processes and consequently reduce net CH 4 emission to the atmosphere. However, restoring drained peatlands through rewetting activities to reach
minimum water level would simultaneously increase CH 4 emission (Beetz et al.
2013). This arises when the water level rises which tends to create environment with
anaerobic conditions, so methanogenic bacteria produce more CH 4 . In the agricultural sector, CH 4 is produced from anaerobic degradation of organic matters in the
rice field, natural wetlands, landfills, digestive tracts of a ruminant class of animals,
production and utilization of oil and natural gas, and incomplete combustion of
organics (Kumar et al. 2020). Due to the significant role of CH 4 in the net GHG
tropical peatland balance, continuous measurement of CH 4 flux over many years is
needed (Hooijer et al. 2010).
15.2.3 Nitrous Oxide (N 2 O) Emission
The next GHG with a long atmospheric residence time is nitrous oxide (N 2 O).
Primarily, N 2 O is produced by the burning of biomass and nitrogen-rich fuels
(especially coal), decomposition of nitrogen fertilizers in the soil, livestock wastes,
and nitrate-contaminated groundwater (Kumar et al. 2020). Denitrification and
nitrification are the main processes that produce N 2 O on peatlands, which are
affected by peat drying events. The diversity of peat water content will affect the
level of resulted N 2 O emission. The response of N 2 O emission reduction in groundwater level can vary according to the intrinsic nature of peat. According to Beetz
15 Climate-Responsible Management of Tropical Peatlands: The Need for Integrated. . .
447
utilization and CO 2 emission in tropical peatlands is still insufficient. Kumar and
Imam (2013) noted that CO 2 is produced by fossil fuel consumption, deforestation,
and degradation of biomass sources, resulting in the oxidation of carbon compounds
in peat and forests.
15.2.2 Methane (CH 4 ) Emission
Methane (CH 4 ) is the second GHG after CO 2 in terms of atmospheric concentration
and emission frequency, but 25 times more in global warming potential (GWP)
(Hooijer et al. 2010). CH 4 is a powerful GHG and has a significant influence on the
earth’s climate. It has an important role in the formation of O 3 and influences climate
parameters (Kumar and Imam 2013). CH 4 emission from peatlands (either drained or
undrained) are modest in comparison with CO 2 emission (Couwenberg et al. 2009;
Hooijer et al. 2010). In the event of peat fires, CH 4 is produced in addition to CO 2
and CO. Methane emission also occur due to changes in the process of
methanogenesis that occur due to changes in land use and land cover on peatlands
as well as peat drainage.
Decreasing water level after drainage can reduce methanogenesis but increase
methanotroph processes and consequently reduce net CH 4 emission to the atmosphere. However, restoring drained peatlands through rewetting activities to reach
minimum water level would simultaneously increase CH 4 emission (Beetz et al.
2013). This arises when the water level rises which tends to create environment with
anaerobic conditions, so methanogenic bacteria produce more CH 4 . In the agricultural sector, CH 4 is produced from anaerobic degradation of organic matters in the
rice field, natural wetlands, landfills, digestive tracts of a ruminant class of animals,
production and utilization of oil and natural gas, and incomplete combustion of
organics (Kumar et al. 2020). Due to the significant role of CH 4 in the net GHG
tropical peatland balance, continuous measurement of CH 4 flux over many years is
needed (Hooijer et al. 2010).
15.2.3 Nitrous Oxide (N 2 O) Emission
The next GHG with a long atmospheric residence time is nitrous oxide (N 2 O).
Primarily, N 2 O is produced by the burning of biomass and nitrogen-rich fuels
(especially coal), decomposition of nitrogen fertilizers in the soil, livestock wastes,
and nitrate-contaminated groundwater (Kumar et al. 2020). Denitrification and
nitrification are the main processes that produce N 2 O on peatlands, which are
affected by peat drying events. The diversity of peat water content will affect the
level of resulted N 2 O emission. The response of N 2 O emission reduction in groundwater level can vary according to the intrinsic nature of peat. According to Beetz
15 Climate-Responsible Management of Tropical Peatlands: The Need for Integrated. . .
447