Presented by Stephen Crooks (PhD) with Michelle Orr (PE) & Kris May (PhD, PE) on 24 September 2019 at Blue Carbon Regional Workshop, Merida, Yucatan.

1. www.silvestrum.com
Structured Planning of Restoration Projects
Linking Science to Outcomes
Stephen Crooks (PhD)
with
Michelle Orr (PE), & Kris May (PhD, PE)
Blue Carbon Initiative
Copenhagen, Denmark
Sept 10th 13th 2019
Jim Fourqurean

2. www.silvestrum.com
Integrated Coastal Management
Drivers
Climate Change,
SLR, food production,
Urbanization,
transport
Pressures
Flooding
Nutrient loading,
Industrial, pollution,
sewage, water needs
State
Reduced habitat,
eutrophication,
species decline
sediment budgetImpact
Reduced welfare,
biodiversity loss,
Fisheries decline,
water quality
GHG emission/ store
Response
Habitat protection,
Emissions control
Levee realignment
(Crooks and Turner, 1999
Advances in Ecological Research)
Monitoring
Modeling
Vulnerability Analysis
Ecological Impact Assessment
Economic valuation
Benefits analysis
Scenario analysis
Adaptive Management
Adaptation
Mitigation

3. www.silvestrum.com
Goal of Restoration (Adaptation)

4. www.silvestrum.com
Goal of Carbon Management
Source: Forest Trends

5. www.silvestrum.com
Planning Approach (Project / Landscape Context)
• Set Goals and Objectives: goals represent the overall vision of the project, objectives the
implementable outcomes.
• Approach and success criteria: summarizes the framework to achieve project objectives. What
science is needed, who are the actors involved, what will be done? Success criteria are qualifiable
metrics that measure project progress.
• Site setting: describes the antecedent, cultural and environmental setting, history of human
interventions, and current site conditions;
• Opportunities and constraints sets the boundaries for what is actionable and achievable for
through the project.
• Conceptual model: clearly articulates the concepts upon which the project will be based. Provides
description to enable external validation. Links objectives of project, physical description of the
site, design and implementation and monitoring requirements.
• Field data collection, calibration and validation of conceptual models.
• Activity / design description: on the ground actions to be undertaken to achieve project
objectives.
• Project monitoring : links back to success criteria and conceptual models. Required for MRV and
adaptive management

6. www.silvestrum.com
Building
Confidence and
Support
In a victory for San Francisco Bay, Measure
AA received 69% of the vote in the nine-
county Bay Area, putting it over the 2/3
majority it needed to pass.
Provides $25 million / year for 20 years.
Measure AA will provide funds to:
• Restore San Francisco Bay wetlands
• Reduce trash and other pollution in the Bay
• Protect shoreline communities from future
flooding
• Increase trails and parks along the Bay shoreline

7. www.silvestrum.com
California Bonds for Climate Resiliency Projects Initiative (2020)
The ballot measure would authorize $7,883,000,000 in
bonds for projects related to climate resilience:
• $3,508,000,000 for "wildfire prevention and community
resilience from climate impacts";
• $2,200,000,000 for "safe drinking water, protecting
water supply and water quality from climate risks";
• $975,000,000 for "protecting fish and wildlife from
climate risks";
• $200,000,000 for "protecting agricultural land from
climate risks";
• $770,000,000 for "protecting coastal lands, bays, and
oceans from climate risks"; and
• $230,000,000 for "climate resilience, workforce
development, and education."

8. www.silvestrum.com
Conceptual model examples
- Wetland response to sea level rise
- Flood projection response to SLR
- Sediment budget
- Marsh drowning risk
- Ecosystem evolution
- Landscape connectivity
- Project phasing
- Flood management
- Waterway hydrology /sedimentation
South Bay Salt Ponds
Key are metrics
of resilience and
identification of
thresholds

9. www.silvestrum.com
Conceptual model needs
- Wetland response to sea
level rise
- Sediment (OM and mineral
budget
- Channel excavation based
on hydraulic geometry.
- Vegetation elevation
- Ecosystem evolution
- Landscape connectivity
- Fish utilization
Liberty Island Conservation Bank

10. www.silvestrum.com
Conceptual models examplesHamilton Army Airbase
Wetland Restoration
- Tidal wetlands, seasonal
wetlands and upland ecotone.
- Sediment accretion/
consolidation
- Wetland response to sea
level rise
- Salt balances
- Impacts of waves on
sedimentation and structures
- Channel evolution
- Landscape connectivity
- Bird and fish utilization
- Wildlife disturbance
- Mercury methylation in ponds

11. www.silvestrum.com
Jim
Fourqurean
Challenges: inventories, methodological
approaches and activity data
Dr. Stephen Crooks
Silvestrum Climate Associates
Blue Carbon and NDC Technical Working Group
Merida, Mexico September 24-25th, 2019

12. www.silvestrum.com

13. www.silvestrum.com
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Tall Medium Dwarf Shrimp pond Mean Mangrove
Carbonstock(CO2eMg/ha)
CARBON STOCKS OF NEOTROPICAL MANGROVES ARE AMONG THE
LARGEST OF ALL TROPICAL FORESTS
Ecosystem C stocks in CO2e, Republica Dominicana
Kauffman, Cifuentes et al. 2013
Abovegrd
belowgd plant
Downed Wood
0-15
15-30
30-50
50-100
>100

14. www.silvestrum.com
Carbon fluxes and storage

15. Revision/Update by the IPCC
IPCC Inventory Guidelines
and UNFCCC
1995 IPCC
Guidelines
Revised 1996
IPCC Guidelines
GPG2000
(non-LULUCF)
GPG2003
(LULUCF)
2006 IPCC
Guidelines
Currently, Non Annex I Parties use
these under the UNFCCC. Annex I Parties must use
from 2015
Non-Annex I Parties are
encouraged to use GPGs.
Actually, 2006 Guidelines
are being used by more and
more Non-Annex I Parties.
＋
New Supplementary Guidance in 2013
＋
2019Refinementtothe2006IPCCGuidelines
2013 Wetlands Supplement

16. 2013 Wetlands Supplement
• The 2013 Supplement to the 2006 IPCC Guidelines for
National Greenhouse Gas Inventories: Wetlands
(Wetlands Supplement)
– was adopted/accepted by IPCC
in October 2013.
– provides methodological guidance
on lands with wet and drained soils,
and constructed wetlands for
wastewater treatment.

17. 2013 Wetlands Supplement
• Currently, under the UNFCCC, the Parties included
in Annex I to the Convention (= developed and some
EIT countries) are encouraged to use the Wetlands
Supplement.
[Decision 24/CP.19]
• From 2024, under the Paris Agreement, all Parties
are encouraged to use the Wetlands Supplement.
[Decision 18/CMA.1]

18. Chapter 4 of 2013 Wetlands Supplement
• One new element of the 2013 Wetlands Supplement is
guidance on specific management activities in coastal
areas of mangroves, tidal marshes and seagrass
meadows. (Chapter 4)

19. www.silvestrum.com
Chapter 4: Coastal Wetlands of the 2013 Supplement to the 2006 IPCC
Guidelines for National Greenhouse Gas Inventories: Wetlands
• Updated default data for estimation of C stock changes in mangrove living
biomass and dead wood pools
• New generic methodological guidance and data on:
– CO2 emissions and removals on coastal wetlands on organic and
mineral soils for specific management activities
– N2O emissions during aquaculture use
– CH4 emissions from rewetted soils and creation of mangroves and tidal
marshes

20. Guidance to Estimate CO2, CH4 and N2O Fluxes from
Management Activities in Coastal Wetlands – Consistent with
2006 GLs but also captures E/R that fall outside of land base
Activity
Coastal
Vegetation
Types Affected*
Sub-Activity
New/Updated Guidance or Data
Provided in Coastal Wetlands Chapter
of the Wetlands Supplement
Activities Relevant to CO2 Emissions and Removals
Forest
Management
M
Planting, thinning, harvest, wood removal, fuelwood removal
and charcoal production. Including conversion to or from
Forest Land
Updates to 2006 GLs default data for
estimation of C stock changes in biomass ,
dead organic matter and soil C pools
Extraction
M, TM, SGM
Excavation to construct port, harbor or marina; filling or
dredging to raise elevation of land
New guidance , data and EFs provided for
estimation of CO2 emissions and removals
from biomass, dead organic matter and
organic/mineral soils
M, TM Construction of aquaculture facilities
M, TM Construction of salt production facilities
Drainage M, TM Agriculture, forestry, mosquito control
Rewetting,
revegetation
and creation
M, TM
Conversion from drained to saturated soils by restoring
hydrology and vegetation
Revegetation SGM Reestablishment of vegetation on undrained soils
Activities Relevant to non-CO2 Emissions
Aquaculture
(use)
M, TM, SGM N2O emissions from aquaculture use
New methodological guidance and EFs for
estimating N2O emissions from aquaculture
use
Rewetting,
revegetation,
and creation
M, TM, SGM
CH4 emissions from rewetting, revegetation and creation of
wetlands
New methodological guidance and EFs for
estimating CH4 emissions from rewetting,
revegetation and creation of M, TM, SGM
*M=Mangroves, TM= Tidal Marsh, SGM=Sea Grass Meadows

21. www.silvestrum.com

22. www.silvestrum.com
Methodological Tiers*
Tier 3: Higher order methods
Detailed modeling and/or inventory measurement systems
Data at a greater resolution
Tier 2: A more accurate approach
Based on Tier 1 with country or region-specific values for
the general defaults, greater stratification
More disaggregated activity data
Tier 1: Simple first order approach
Default values of the parameters from the IPCC guidelines
Spatially coarse default data based on globally available
data
* Different tiers can be applied to different C pools, if all data do not support the highest tier approach

23. www.silvestrum.com
Wetland Supplement Reference Stocks

24. www.silvestrum.com
Wetland Supplement – C Emissions / Removals

25. www.silvestrum.com
Inclusion of Coastal Wetlands into the U.S.
Inventory of GHG Emissions & Sinks
Stephen Crooks and Lisa Beers
Silvestrum Climate Associates
Tom Wirth
U.S. Environmental Protection Agency
Tiffany Troxler
Florida International University
Nate Herold, Meredith Muth,
Ariana Sutton-Grier, Amanda McCarty
National Oceanic & Atmospheric Administration
Blanca Bernal, James Holmquist & Pat Megonigal
Smithsonian Environmental Research Center
Steve Emmett-Mattox, Stefanie Simpson
Restore America’s Estuaries
Incorporating Coastal Wetlands into National GHG Inventories
International Blue Carbon Partnership
Brisbane, July 12-13
Jim Fourqurean
Photo: Jacqueline Rose

26. www.silvestrum.com
U.S. Coastal Wetland Carbon Working Group
U.S. National Oceanic and Atmospheric Administration (Coastal Management,
Habitat Conservation, International), U.S. Environmental Protection Agency
(Climate Change, Wetlands), U.S. Geological Survey, U.S Forestry Service,
Environmental Science Associates, Florida International University, Smithsonian
Environmental Research Center, Restore America’s Estuaries, Colorado State
University, Pennsylvania State University, Texas A & M.

27. “Blue” Carbon Monitoring System
Linking soil and satellite data to reduce uncertainty in coastal wetland carbon burial:
a policy-relevant, cross-disciplinary, national-scale approach
Lisamarie Windham-Myers (18 Science PIs; October 2014-17)
Federal
USGS Brian Bergamaschi
Kristin Byrd
Judith Drexler
Kevin Kroeger
John Takekawa
Isa Woo
Postdoc:Meagan Gonneea
NOAA-NERR Matt Ferner
Smithsonian Pat Megonigal
Don Weller
Lisa Schile
Postdoc:James Holmquist
NASA-JPL Marc Simard
Non Federal
U. South Carolina Jim Morris
U. Maryland/NOAA Ariana Sutton-Grier
U. San Francisco John Callaway
Florida Intl. U. Tiffany Troxler
Texas A&M U. Rusty Feagin
Independent Stephen Crooks

28. 28
Kroeger, K., Crooks, S., Moseman-Valtierra, S. & Tang, J. 2017. Restoring tides to avoid
methane emissions in impounded wetlands: A new and potent Blue Carbon climate
change intervention. Nature, Scientific Reports
Crooks. S., Troxler, T., Sutton-Greer, A, Herold, N.& Wirth T. (2018). The U.S. Experience
Including Coastal Wetland Management in the National Greenhouse Gas Inventory.
Nature Climate Change.
Holmquist, J.R., Windham-Myers, L., Bliss, N., Crooks, S. and 29 more. (2018). The
Accuracy and Precision of Soil Carbon Stock Estimates for Tidal Wetlands in the
Contiguous United States. Nature, Scientific Reports
Holmquist, JR, L Windham-Myers, B Bernal, K Byrd, S Crooks, M Gonneea, N Herold, S
Knox, K Kroeger, J McCombs, P Megonigal, L Meng, J Morris, T Troxler, D Weller (2018)
Uncertainty in United States Coastal Wetland Greenhouse Gas Inventory.
Environmental Research Letters.
Troxler, T., Kennedy, H., Crooks., S. and Sutton-Greer, A. 2019 Introduction of Coastal
Wetlands into the IPCC GHG Methodological Guidance. Chapter 16 in Windham-
Myers, L.M., S.Crooks, and T. Troxler 2019. A Blue Carbon Primer: The State of Coastal
Wetland Carbon Science, Practice and Policy. CRC Press, New York.
“Blue” Carbon Papers and Books

29. www.silvestrum.com
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2016
In 2016 gross US GHG emissions were 6,511 MMT CO2e. An increase of 2.4% above
1990 and a drop of 1.9% below 2015.
LULUCF Sector net sink of 717 MMTCO2e Coastal Wetlands net sink of 8.5 MMtCO2e

30. www.silvestrum.com
United States: Emissions of Interest
• Emissions and removals of CO2 and CH4 on intact and
restoring wetlands.
• Drainage and excavation activities
• Conversion of wetlands to open water
• Forestry activities on wetland soils
• CH4 emissions from impounded waters
• Aquaculture

31. www.silvestrum.com
Inventory: Coastal Wetland Chapters Included
• 6.8 Vegetated Coastal Wetlands Remaining
Vegetated Coastal Wetlands
– Vegetated Coastal Wetlands Converted to Open Water
Coastal Wetlands
– Open Water Coastal Wetlands Converted to Vegetated
Coastal Wetlands
• 6.9 Lands Converted to Vegetated Coastal Wetlands

32. www.silvestrum.com
Methodological Approach
• Scope emissions and removals of interest / capabilities
• Decision: activity-based analysis or apply Managed Land Proxy
• Define Coastal Land Area based upon extent of tides and Land Representation.
• Quantify land use within Coastal Land Area
• Quantify land use change 1990-2018.
• Ascribe a CO2 and CH4 emissions factor for land use change based upon Tier 1
default values or country-specific data for C stocks, stock change and CH4 flux.
• Estimate N2O emissions from aquaculture based upon T1 emissions factor and
annual survey of aquaculture production.
• Calculate annual emissions and removals:
– Coastal Vegetated Wetlands Remaining Coastal Vegetated Wetlands
– Coastal Vegetated Wetlands converted to Coastal Wetlands Open Water
– Lands Converted to Coastal Wetlands.
– Coastal Wetlands Converted to Lands (reported under other land use categories)

33. www.silvestrum.com
U.S. Analysis: Methodological Tiers*
Tier 3: Higher order methods
Potential future improvements. Focus of ongoing research.
Tier 2: A more accurate approach (country specific)
Land cover change (CCAP: 30 m resolution, 4 epochs)
Soil carbon stocks, C sequestration (Literature review)
Tier 1: Simple first order approach
Depth of eroded soil (1m), based on T1 excavation procedure.
Methane emissions EF (IPCC 2014) and mapped salinity threshold
Aquaculture N2O emissions factors
* Different tiers can be applied to different C pools, if all data do not support the highest tier approach

34. www.silvestrum.com
•National Coastal Land Cover Monitoring Program
–Updated every five years since 1996
•Based on Landsat imagery (30m)
–Regional to county scale in scope
•Consistent, Accurate Products
–FGDC National Geospatial Data Asset
•25% of the contiguous U.S. (CONUS)
–Coastal expression of the NLCD
•Additional Coastal Detail
–Focus on wetland categories
–More dates / longer time series
C-CAP Regional Land Cover and Change
coast.noaa.gov/digitalcoast/data/ccapregional

35. San Francisco Bay – San Joaquin River, CA New Orleans – Mississippi River, LA Chesapeake Bay – Blackwater National
Wildlife Refuge, MD
Extent of
Coastal Land
Area
Tide data
Lidar surface
C-CAP land cover

36. www.silvestrum.com
San Francisco Estuary, CA

37. www.silvestrum.com
CONUS Coastal Land Area: Land Use and Soils
Land Use Category Total Area Organic Soil Mineral Soil
(Ha) Area (ha) Area (%) Area (ha) Area (%)
Developed Land 151,304 37,667 24.9 113,637 75.1
Cultivated Land 267,137 114,567 42.9 152,571 57.1
Grassland (inc Scrub) 65,909 17,499 26.5 48,410 73.5
Forest Land (Dry) 45,401 5,358 11.8 40,042 88.2
Palustrine F, SS & EM 1,607,306 984,454 61.2 622,852 38.8
Estuarine F, SS & EM 2,188,624 1,064,223 48.6 1,124,400 51.4
Soil data from Soil Survey Geographic DatabaseTotal coastal land area: 4,325,681 ha
Settlement or dry drained agro-forestry: 13%

38. www.silvestrum.com
CONUS Coastal Land Area: Land Use and Soils
Land Use Category Total Area Organic Soil Mineral Soil
(Ha) Area (ha) Area (%) Area (ha) Area (%)
Developed Land 151,304 37,667 24.9 113,637 75.1
Cultivated Land 267,137 114,567 42.9 152,571 57.1
Grassland (inc Scrub) 65,909 17,499 26.5 48,410 73.5
Forest Land (Dry) 45,401 5,358 11.8 40,042 88.2
Palustrine F, SS & EM 1,607,306 984,454 61.2 622,852 38.8
Estuarine F, SS & EM 2,188,624 1,064,223 48.6 1,124,400 51.4
Annual emissions from drained organic former wetland soils:5,071,805 tCO2

39. www.silvestrum.com
Wetlands Remaining Wetlands (2016)
Annual emissions and removals (parentheses)
Land Cover Total Area C Sequest CH4 emissions Total removal
(Ha) tCO2 / yr t CO2e/yr t CO2e/yr
Palustrine Forest 873,340 NA NA NA
Palustrine S Shrub 138,749 (687,394) 675,900 (11,494)
Palustrine E Marsh 599,146 (3,458,534) 2,901,425 (899,393)
Estuarine Forest 191,550 (681,471) - (681,471)
Estuarine S Shrub 97,099 (350,224) - (350,224)
Estuarine E Marsh 1,852,842 (6,902,298) - (6,902,298)
Total 3,795,930 (12,079,921) 3,577,325 (8,502,596)

40. www.silvestrum.com
Wetland Conversions (1990-2016)
Land Use Change Net Emission
MMtCO2 / yr
Wetland to Open Water 1.27-7.19
Wetland Drainage 0.70-1.92
Wetland Restoration 0.015-0.025

41. www.silvestrum.com
Summary: Considerations for Management
• Coastal Wetlands sequester net 8.5 MMTCO2e/yr.
• Preventing new drainage would avoid 0.7 – 1.9 MMTCO2e/yr.
• Restoring wetlands on drained organic soils (non developed)
would avoid emissions of 4 MMTCO2e/yr.
• Restoring tidal connection to hundreds of small scale
impounded waters would avoid reduce of 1-3 MMTCO2e/yr.
• Wetlands erosion releases 1-7 MMTCO2e/yr.
• Current restoration accounts for only 0.02 MMTCO2e/yr of
new carbon sequestration

42. www.silvestrum.com
Main Sources of Error
• Small data set for Palustrine wetlands (C stocks, stock change
and CH4).
• Trend changes: extrapolation from 4 CCAP data points 1996,
2001, 2006, 2010. (2015 to be released this year)
• Methane: estuarine / palustrine delineated by 5 ppt salinity.
Emissions factors by 18 ppt.
• Soil C erosion losses: based upon Tier 1 assumption of 1 m
depth of soil erosion.
• Fate of C: 100% of eroded C returns to atmosphere. (Standard
across inventory.)

43. www.silvestrum.com
Planned and Potential Improvements
Planned
• Inclusion of biomass (2019)
• Refined dataset and database on soil carbon stocks (2019)
• Refined uncertainty analysis (2019)
• Inclusion of CCAP 2015 in trend analysis (2020)
• Refined tidal boundary (2020)
• Further integration with NRI and FIA datasets
Potential
• Inclusion of seagrass meadows
• Improved C and CH4 fluxes from palustrine wetlands
• Improved quantification of fluxes from impounded water
• Impacts of forestry activities on wetland soils
• Inclusion of wetlands above the Coastal Land Area.

44. www.silvestrum.com
Jim
Fourqurean
Bridging Development of NDCs and GHG
Inventories for Coastal Wetlands
Dr. Stephen Crooks
Dr. Moritz von Unger
Silvestrum Climate Associates
Incorporating Blue Carbon into NDCs
Hanoi July 9-10th, 2019

45. www.silvestrum.com
Linking Inventories and NDCs for BC
• Accounting is fundamental to mitigation and adaptation policies.
– Particularly land use change
• UNFCCC is inviting Parties to apply the Wetland Supplement
• For some countries BC emissions and removals may be significant for others not.
• Countries at different levels of preparation from first thoughts to advanced.
• Before going to far begin with a scoping assessment
– Are there losses of BC?
– Have policies been put in place that would influence emissions / removals trend?
– Begin simple with default values of no national state and estimate of LUC
• If significant some countries may need assistance to advance:
– Methods (calculations of stocks and ERs and data collection)
– Data archiving,
– MRV for BC
– Harmonization with REDD
• Don’t promise too much in NDCs in terms of mitigation until after scoping.
• For those who can to take first steps in applying the Supplement

46. www.silvestrum.com 47
Stephen Crooks Ph.D.
Principal: Coastal Management/ Wetland Science
Silvestrum Climate Associates
1 415 272 3916
steve.crooks@silvestrum.com
www.Silvestrum.com
www.Facebook.com/silvestrumclimate
Qwuloolt tidal Wetland Restoration
(Image: Tulalip Tribes)

47. www.silvestrum.com
Inclusion of Blue Carbon in national inventories
– Example questions from an inventory compiler

48. www.silvestrum.com
Outline
• Coastal wetlands
• What does the IPPC guideline say?
• Paris Agreement and EU regulation 529
• Responsibility
• Reporting
• Human induced versus natural emissions
• Mitigation options
• Leaking

49. www.silvestrum.com
Coastal Wetlands
• We have to report all land
– Human induced?
– National border – 12 nautical miles ?
• No cherry picking
– Where do we have influence ?

50. www.silvestrum.com
Climate Convention versus
Paris Agreement
• UNFCCC
• National emission estimates – no commitments
• UNFCCC is only a reporting obligation. The reporting obligation differ between countries. Annex I
and Non-Annex 1 countries
• Paris Agreement
• Nationally determined contributions
• The Paris Agreement requires all Parties to put forward their best efforts through nationally
determined contributions (NDCs) and to strengthen these efforts in the years ahead. This includes
requirements that all Parties report regularly on their emissions and on their implementation
efforts.

51. www.silvestrum.com
Guidance in relation to the mitigation section
of the Paris Agreement
• Assumptions and methodological approaches
- Assumptions and methodological approaches specific to LULUCF, forests
and REDD+, if included in NDC:
- treatment in NDC (e.g. accounting like any other sector, sectoral target);
- use of base years/base periods/reference levels;
- construction of any specific baselines for land use categories/activities.
- Ensure avoidance of double counting in relation to use of Article 6
internationally transferred mitigation outcomes toward NDCs;
- The contribution from forest and land use to represent real, permanent
and verifiable emission reductions that would not occur irrespective of the
Party's actions;
• Parties to be encouraged to include the land sector in their NDCs, and
those that include it to continue to do so in the future.

52. www.silvestrum.com
What does the IPPC guidelines say?
• CHAPTER 4
– COASTAL
WETLANDS

53. www.silvestrum.com
• CHOICE OF EMISSION/REMOVAL FACTORS Tier 1
– The choice of EFs at Tier 1 is applied based on the
coastal wetland vegetation type being established
through the rewetting, revegetation or creation
activity…….
– If vegetation is reestablished through direct
reseeding….
– If the rewetting, revegetation or creation activity is
associated with recolonization (no direct replanting
or reseeding), apply EFRE = 0.
– If the rewetting and revegetation activity results in
patches of biomass (if coverage data are available),
EFRE >0 should only be applied when the mangrove,
tidal marsh plant or seagrass canopy covers at least
10% of the overall area. This consideration follows
the definition of forest (Table 4.2, Chapter 4,
Volume 4, 2006 IPCC Guidelines)
What does the IPPC guidelines say?

54. www.silvestrum.com
Double counting
• Both under- and overestimating
• In my inventory I have leaching of
dissolved organic matter (OM) from
organic soils
• Assumed instant oxidation
(OM→ C → CO2)
• YOU have to ensure that this leached
OM is not part of what you are
measuring – the origin of the carbon

55. www.silvestrum.com
The most important challenges
• From reporting view
– Only human induced – take out effects due to global
warming
– Which areas should be included – no cherry picking – are
you biased in your research?
– Scientific sound baseline estimation
– Stable annual estimates of the current C stock in the
wetlands
• Projection
• Model/driving variables
– Be part of a scientific discussion on double counting
• CO2
• CH4
• Mass balance ?

56. www.silvestrum.com