Post on 08-Feb-2016
description
Challenges and options
John CouwenbergHans JoostenGreifswald University
Are emission reductions from peatlands MRV-able
Stocks & emissions
Current Carbon stock in peat soils:
~550 000 Mt C
Current emissions from drained peatlands:
>2000 Mt CO2 y-1
Global CO2 emissions from drained peatlands
Drained area
(106 ha)
CO2 (ton ha-1 y-1)
Total CO2 (Mton y-1)
Drained peatlands in SE Asia 12 50 600
Peatland fires in SE Asia 400
Peatland agriculture outside SE Asia 30 25 750
Urbanisation, infrastructure 5 30 150
Peat extraction 30 1 60
Boreal peatland forestry 12 1 12
Temperate/tropical peatland forestry 3.5 30 105
Total 63 2077
Mitigation management options
• Conservation of the C stock • Sequestration of C from the atmosphere• Substitution of fossil materials by biomass.
Conservation management
Conserve existing peat C pools:• Prevent drainage• Reverse drainage by rewetting
yearly emissions
time
Reducing the rate of deforestation(rate of reclamation of new areas)
yearly emissions
time
Reducing the rate of peatland drainage(rate of reclamation of new areas)
Peatlands continue emiting for decades after drainage:Annual emissions are cumulative
Conservation management
Rewetting is the only option to reduce emissions
Strategic rewetting of 30% (20 Mio ha) of the world’s drained peatlands could lead to an annual emission avoidance of almost 1000 Mtons CO2 per year.
Sequestration management• ~75% of peatlands are still pristine• accumulating new peat • removing & sequestering 200 Mtons CO2 y-1
strict protection
• rewet 20 Mio ha• restore peat accumulation in 10 Mio ha additional removal ~10 Mtons CO2 y-1
Substitution management• replacing fossil resources by biomass from drained peatlands: CO2 emitted > CO2 avoided
• biomass from wet peatlands orpaludiculture (= wet agriculture and forestry)
• implemented on 10 Mio ha of rewetted peatland substitution of 100 Mtons of CO2
Peatland management• avoiding peatland degradation and • actively restoring peatlands• results in significant climate benefits
quantify emission reductions
Measure drained…
… and (re-)wet(ted) situation...
frequent, prolonged, intensive
expensive, complex, time consuming
Peenetal
Measure pilot sites, develop proxies for the rest
Proxies: water level
-120-100-80-60-40-200
mean annual water level [cm]
t CO2 ha-1 y-1
0
10
20
30
40
50
Good proxy for CO2 emissions:Example temperate Europe
Proxies: water level
-100
0
100
200
300
400
500
600
-100 -80 -60 -40 -20 0 20 40 60
mean water level [cm]
kg C
H4?
ha-1
y-1
-2
0
2
4
6
8
10
12
t CO
2-eq
?ha-1
y-1
Good proxy for CH4 emissions:Example temperate Europe
-0,5
0
1
2
3
CH4 emission [mg m-2 h-1]
0
5
10
15
-100 -80 -60 -40 -20 0 20water level [cm]
Proxies: water levelGood proxy for CH4 emissions:
Boreal/tempEurope
SEAsia
At high water levelsdifferences due tovegetation
Emissions strongly related to water level Vegetation strongly related to water level
Use vegetation as indicator for emissions
Proxies: vegetation
• developed for NE Germany• currently being verified, calibrated and updated
for major peatland rewetting projects in Belarus.
Proxies: vegetation
Advantages of using vegetation • reflects longer-term water level conditions • reflects factors that determine GHG emissions
(nutrient availability, acidity, land use…),• itself determines GHG emissions
(quality of OM, aerenchyma mediated CH4)• allows fine-scaled mapping
(1:2,500 – 1:10,000)
Proxies: vegetation
Disadvantage of using vegetation • slow reaction on environmental changes• necessity to calibrate for different climatic and
phytogeographical conditions.
GESTs: Greenhouse gas Emission Site Types
GESTs with indicator species groups
GEST: moderately moist forbs & meadowsVegetation forms:
Urtica-Phragmites reedsAcidophilous Molinia meadowDianthus superbus-Molinia meadow…
Each with typical / differentiating speciesEach GEST with GWP
Proxies: subsidence
• loss of peatland height due to oxidation• complication: consolidation, shrinkage• promising especially in the tropics:
subsidence based methodology being developed by the Australian-Indonesia Kalimantan Forests Carbon Partnership.
Proxies: subsidence
0
1
2
3
4
5
6
7
-120 -100 -80 -60 -20 0
subsidence [cm y-1]
0
Estimated emission [t CO 2 ha-1 y-1 ]
8
9
10
10
20
30
40
50
60
70
80
90
-40
drainage depth [cm]
Oxidative componentderived from changesin bulk density andash content:
Proxies: subsidence
• possible to measure using remote sensing and ground-truthing
• works well for losses from drained peatlands, but less for decrease in losses under rewetting (swelling)
Monitoring emission reductionsfrom rewetting and conservation
• wide range of land use categories• may require different approaches to
– reduction of GHG emissions – monitoring these reductions
• land use may enhance GHG emissions(plowing, fertilization, tree removal)
Monitoring emission reductionsfrom rewetting and conservation
Avoided emissions need clear baseline• clear in case of rewetting• proxy approach for avoided drainage
– Note: peat depth determines duration of possible emissions after drainage
Monitoring emission reductionsfrom rewetting and conservation
• cost of monitoring is related to the desired precision of the GHG flux estimates.
• determined by market value of ‘carbon’ • assessing the GHG effect of peatland
rewetting by comprehensive, direct flux measurements might currently cost in the order of magnitude of € 10 000 ha-1 y-1
Monitoring by proxies
Monitoring GHG fluxes using water levels:• data frequent in time, dense in space.
field observations and automatic loggers.
• water level modelling based on weather data
• remote sensing not yet suited
Monitoring by proxies
Monitoring GHG fluxes using Vegetation:• easily mapped and monitored in the field
• monitoring by remote sensing has been tested successfully and is very promising, also in financial terms.
Monitoring by proxies
Monitoring GHG fluxes using subsidence:• easily monitored by field observations, but
practically impossible over large areas when annual losses are high.
• In tropical peatlands (several cm y-1) the use of LiDAR looks very promising.
Monitoring of proxies
• derivation of actual emissions from proxies open to improvement
conservative estimates indicate thatreduced and avoided emissions
from peatland rewetting and conservation can provide a major contribution to
climate change mitigation