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