Mar 9, 2006 - and Greenhouse Gas Emissions. LULUCF. CO. 2. 22%. CH. 4. 55%. N .... INDIANA. COUNTY BLACKFORD. FOR INDICATED SOILS ON MAP ...
World Soil Issues and Sustainable Development: An agenda for Action 40 years ISRIC – World Soil Information (Anniversary Seminar, 9th March 2006, Wageningen)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Carlos C. Cerri, Carlos E. P. Cerri, David Powlson, Niels H. Batjes, Martial Bernoux, Keith Paustian, Eleanor Milne, Charles W. Rice
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas (GHG) Emissions
TOPICS General Considerations Importance of soil organic carbon Carbon balance and sequestration The tropics Carbon sequestration and international effort
Soil Organic Carbon / GHGs in the tropics Known knows Known unknowns Unknown unknowns
Final Considerations
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas (GHG) Emissions
TOPICS General Considerations Importance of soil organic carbon Carbon balance and sequestration The tropics Carbon sequestration and international effort
Soil Organic Carbon / GHGs in the tropics Known knows Known unknowns Unknown unknowns
Final Considerations
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Importance of SOC at global scale
Emissions
Atmosphere
Pg 730 +
Vegetation
470-655
Soil (0-30cm)
~700
Soil (1m)
1500-2000
Values in Gt C (1Gt = 109 t = 1 Pg)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Emissions
Importance of SOC at global scale Atmosphere
Pg 730
Vegetation
470-655
Soil (0-30cm)
~700
Soil (1m)
1500-2000
Values in Gt C (1Gt = 109 t = 1 Pg)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Importance of SOC at global scale
Sequestration
Emissions
Atmosphere
Pg 730 -
Vegetation
470-655
Soil (0-30cm)
~700
Soil (1m)
1500-2000
Values in Gt C (1Gt = 109 t = 1 Pg)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Importance of LULUCF to the radiative forcing Radiative forcings* by main sector Agriculture
20%
66% Industries cement And Fuel IPCC-SAR, 1996
Land Use Change
14%
* Change in the energetic balance of the Earth
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Importance of LULUCF to the radiative forcing Radiative forcings* by main sector 1.4 ± 0.2
Agriculture Agriculture
W.m-2
20% CO20% 5%
0.7 ± 0.2 0.15 ± 0.05
CO2
CH4
2
CH4 50% N2O 70%
N2O
66% Industries cement And Fuel IPCC-SAR, 1996
Land Use Change Land Use Change
14% 14%
CO2 17% CH4 5% N2O 10% * Change in the energetic balance of the Earth
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Importance of LULUCF to the radiative forcing Radiative forcings* by main sector 1.4 ± 0.2
Agriculture Agriculture
W.m-2
20% CO20% 5%
0.7 ± 0.2 0.15 ± 0.05
CO2
CH4
2
N2O
LULUCF CO2 22% CH4 55% N2O 80% IPCC-SAR, 1996
CH4 50% N2O 70% Land UseChange Change Land Land Use Use Change
14% 14%
CO2 17% CH4 5% N2O 10%
* Change in the energetic balance of the Earth
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Carbon Balance at the plot scale ∆C plant (aerial)
CO2
∆C plant (root) ∆C litter ∆C soil ∆C soluble ∆C particulate
C soluble C particulate
Time Old System t.0
New System
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
LULUCF
Carbon Sequestration at the plot scale
CO2 22% CH4 55% N2O 80%
It must be computed all 3 gases and reported using the same equivalent
Global Warming Potential (GWP)
CO2
CH4
N2O
1
23
296
CO2 Equivalent 1 kg CH4 = 23 kg CO2eq 1 kg N2O = 296 kg CO2eq C Equivalent 1 kg C-CH4 = 8.4 kg Ceq 1 kg N-N2O = 126.9 kg Ceq
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions LULUCF
CO2 22% CH4 55% N2O 80%
C sequestration ≠ C balance
∆C plant (aerial)
CH4
N 2O
CO2
∆C plant (root) ∆C litter ∆C soil ∆C soluble ∆C particulate
C soluble
∆C gases (CH4, N2O)
C particulate
Time Old System t.0
New System
Versus Alternative system
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
The Tropics Rates of land use change is greatest in the tropics Feed 70% of the population (Lal and Sanchez 1992) Increasing demand for land will be met by converting forest and pasture (C release) ~ 26% of global SOC stocks are in the tropics (Batjes 1996) Relatively little information on soils and how they react to land use change
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Carbon sequestration and international effort ¾ The Kyoto Protocol - CO2 emissions can be offset against carbon removal from the atmosphere ¾ 1st commitment period: 2008 – 2012 ¾ Article 3.3: forestry activities ¾ Article 3.4: management of agricultural soils ¾ Changes before 2008? ¾ UNFCCC -Inventories of CO2 emissions from LUC ¾ Soils sources/sinks C?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Carbon sequestration and international effort
Kyoto Protocol
We need more scientific knowledge
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas (GHG) Emissions
TOPICS General Considerations Importance of soil organic carbon Carbon balance and sequestration The tropics Carbon sequestration and international effort
Soil Organic Carbon / GHGs in the tropics Known knows Known unknowns Unknown unknowns
Final Considerations
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Known Knowns ?
Tropical Soils ? Known Unknowns
? Unknown Unknowns
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Global distribution of soil organic carbon: native condition
? Known knowns
Global soil organic carbon ~ 1500 Pg
0-100 cm WRI, 2000 (FAO, 1995 & Batjes, 1996)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Global distribution of soil organic carbon: native condition
? Known knowns
Global soil organic carbon ~ 700 Pg
Tropical ecosystems ~ 26% or 180 Pg
0-30 cm WRI, 2000 (FAO, 1995 & Batjes, 1996)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Decline in SOM
?
Known knowns
GHG emissions
GHG CO2 N2O CH4
Carbon inputs and SOM decomposition rates are higher in the humid tropics
Soil Carbon stock Remaining from native vegetation DEFORESTATION
Time
Soil Organic Carbon Stocks/Sequestration ? and Greenhouse Gas Emissions Sources of GHG emissions Known knowns
Agriculture and land use change Fossil fuel combustion
Global
G H G (%)
Brazil
22 55 80
CO2 CH4 N2 O
75c 91 94
78%
25%
Global ranking GHG in Brazil
Fossil fuel combustion
Only fossil fuel combustion:
17th
Fossil fuel combustion + Agriculture and land use change
5th
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Soil carbon modelling
Survey data
?
Known knowns
CARBON SEQUESTRATION RURAL APPRAISAL
CURRENT LAND USE INFORMATION FROM LOCAL KNOWLEDGE (SHEET A) STATE
COUNTY
INDIANA
BLACKFORD
FOR INDICATED SOILS ON MAP DETERMINE: MUID (STATSGO ASSOCIATION) IN004 IN005 LAND USE INFORMATION TOTAL CROPLAND
72.9
90.7
IN029
IN032
74 83.4 CARBON SEQUESTRATION RURAL APPRAISAL
CLASS I & II CLASS III & IVGENERAL
LAND USE INFORMATION FROM LOCAL KNOWLEDGE (SHEET B)
Dynamic soil C modelling tool
CLASS V & VI FOREST OR TREES STATE GRASS LANDS
10.9
0.9 INDIANA
14
7.7
8.5
3.1
99.9%
100.0%
100.0%
100.1%
17.5
COUNTY
11.9
BLACKFORD
CARBON SEQUESTRATION RURAL APPRAISAL 0.6 THE COUNTY 0 1.7 ANY 0.1 PART OF BEEN DRAINED (YES/NO): IF YES, ANSWER THE FOLLOWING. 2 0.05 0 GENERAL 0 LAND USE INFORMATION FROM LOCAL KNOWLEDGE (SHEET C)
WATER / WETLANDS HAS URBAN / OTHER TOTAL
ROLLING HILLS
IN004
FLOOD PLAIN
IN005
OTHER TOTAL
IN029
0.0%
OPEN DITCH DRAINAGE INDIANA STATE % OF SOIL TIME PERIOD OF DRAINED INSTALLATION IS 10% OR MORE OF ANY MUID
LANDSCAPE DESCRIPTION MUID FLAT
STEEP HILLS
0.0%
0.0%
0.0%
0.0%
0.0%
COUNTY LEVEL FARMING AND CROPPING SYSTEM HISTORY FROM PRE 1900 TO PRESENT (SHEET D) STATE
MUID
0.0%
0.0%
TILE DRAINAGE BLACKFORD % OF SOIL TIME PERIOD OF CARBON SEQUESTRATION RURAL APPRAISAL DRAINED
COUNTY
INSTALLATION IRRIGATED (YES/NO):
IF YES, ANSWER THE FOLLOWING.
0.0%
0.0%
COUNTY
INDIANA
TIME PERIOD OF % OF SOIL ANNUAL AMOUNT 1970-1990+ TIME FRAME INSTALLATION IRRIGATED APPLIED (INCHES) 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
BLACKFORD
TYPES OF SYSTEMS
ANNUAL CONSERVATION PRACTICES INSTALLED
IN004 PRACTICES INSTALLED 85% BY COUNTY AND SOIL TYPE IN032 % ESTIMATE OF COUNTY BEING FARMED DURING THIS TIME FRAME: TOTAL CROPLAND: % OF THIS SOIL IDENTIFIED AS CROPLAND . THE SUM OF LAND CAPABILITY CLASS I & II, III & IV, AND V & VI MUST ADD TO THIS %. CLASS I & II: % OF THIS SOIL THAT IS CLASS I & II CROPLAND. CLASS III & IV: % OF THIS SOIL THAT IS CLASS III & IV CROPLAND. CLASS V & VI: % OF THIS SOIL THAT IS CLASS V & VI CROPLAND. FOREST OR TREES: % OF THIS SOIL IDENTIFIED AS FOREST OR TREES.
IN005 IN029 IN032
USE IN REPORTING TO DOE FOR CARBON SEQUESTRATION (USE SEPARATE SHEET FOR EACH SOIL MUID)
CROP ROTATIONS (SPECIFY 1 TO 3) 1)
GRASS LANDS: % OF THIS SOIL IDENTIFIED AS GRASS LANDS.
2)
WATER / WETLANDS: % OF THIS SOIL IDENTIFIED AS WETLANDS.
3)
CORN-SOYBEAN
STATE INDIANA
LANDSCAPE DESCRIPTION: % OF THIS SOIL IN EACH LANDSCAPE DESCRIPTION.
FOR INDICATED CROPS CROP NAME YIELD (BU OR TONS/AC)
COUNTY
BLACKFORD
MUID
ACRES OF CONSERVATION PRACTICES INSTALLED (ACRES) GRASS TREE COMMON CROP ROTATION (s) CONVERSIONS PLANTING
URBAN / OTHER LANDS: % OF THIS SOIL IDENTIFIED AS OTHER LANDS INCLUDING URBAN LANDS, DEVELOPED LANDS, ABANDONED LANDS.
CORN
SOYBEAN
130
40
REDUCED TILLLAGE
NO-TILL
REDUCED TILLLAGE
NO-TILL
IN004
WETLANDS CREATED AND/OR RESTORED
1985 1986
N FERT APPLIED (LBS/AC)
110 1987
MANURE APPLIED (TONS/AC)
2
1988
1989 MUID: SOIL MAP UNIT ID FROM STATSGO. (FROM MAP) DISK DISK TYPICAL TILLAGE OPERATIONS MUID: SOIL MA P UNIT ID FROM STA TSGO. (FROM MAP) TIME PERIOD OF INSTALLATION:TIME GIVE THE TIME PERIOD WHEN DRAINAGE PRACTICES 1990 PERIOD OF INSTALLATION: GIVE THE TIME PERIOD WHEN IRRIGA TION PRA CTICES WERE INSTALLLED. (i.e. 1930-1950, 1940-1960, 1970CULTIVATE DISK WERE INSTALLLED. (i.e. 1930-1950, 1940-1960, 1970-1990, ETC.) 1990, ETC.) 1991
PLANT
% OF SOIL IRRIGATED: GIV E A OF N ESTIMA TE FOR THESE OF THEINSTALLED. AMOUNT OF IRRIGATION INSTALLED. % OF SOIL DRAINED: GIVE AN ESTIMATE FOR THESE SOILS THE AMOUNT OF SOILS DRIANAGE
PLANT
1992 CULTIVATE ANNUAL AM OUNT APPLIED (INCHES): GIVE AN ESTIMATE OF THE ANNUAL AMOUNTCULTIVATE OF IRRIGATION WATER APPLIED IN INCHES. (6 INCHES, 12 1993 INCHES, 15 INCHES, ETC.) 1994 TYPES OF SYSTEMS: TYPICAL TYPE OF IRRIGATION SY STEM INSTALLED. (CENTER PIVOT, GATED PIPE, ETC.)
Input database
1995
Comments:
1996 1997 1998
TIM E FRAM E: PERIOD OF TIME AS SPECIFIED. 1999 % ESTIM ATE OF COUNTY BEING FARM ED DURING THIS TIM E FRAM E: GIVE AN ESTIMATE OF THE COUNTY AREA BEING FARMED DURING THIS TIME FRAME. 2000
Simulation models
Output database
TYPICAL CROP ROTATION: CROP ROTATIONS INCLUDE (CORN-CORN; CORN-SOYBEAN; CORN-CORN-OATS-MEADOW-MEADOW; M UID: SOIL MAP UNIT ID FROM STATSGO. (FROM MAP) CORN-SOYBEAN-CORN-OATS-MEADOW-MEADOW; ETC) CROPROTATIONS. ROTATION: PICK THE TWO MOST COMMON CROP ROTATIONS. IF ONE ROTATION IS >90% OF CROPPED ACRES, FOR INDICATED CROPS: ACTUAL CROP INFORMATION FOR THE INDICATED CROPS IN THE REPORT ONLY THAT ROTATION. TOTAL FOR THE COUNTY SHOULD EQUAL THE CTIC REPORTED VALUES FROM 1989 TO CROP: CROP NAME AS SHOWN IN CROP ROTATION. PRESENT. SEE SUPPLEMENTAL INFORMATION. YIELD: CROP YIELD IN BU/AC FOR GRAINS OR TONS/AC FOR HAY. REDUCED TILLAGE: REDUCED TILLAGE FARMING WHICH LEAVE GREATER THAN 15% RESIDUE AFTER PLANTING. (INCLUDES N FERT APPLIED: ESTIMATE OF COMMERCIAL NITROGEN FERTILIZER APPLIED ANNUALLY (LBS/AC). MULCH TILL, RIDGE TILL BUT NOT NO-TILL).
MANURE APPLIED: ESTIMATE OF MANURE APPLIED ANNUALLY (TONS/AC), BY CROP.NO-TILL: NO-TILL FARMING SYSTEM. TYPICAL TILLAGE OPERATIONS: TYPICAL TILLAGE OPERATIONS USED TO GROW THIS CROP. (EXAMPLES ARE FALL PLOW; GRASS CONVERSIONS: ALL GRASS PLANTING CONSERVATION PRACTICES. SPRING PLOW; CHIESEL PLOW; DISK; HARROW; CULTIVATOR; DRILL; PLANT; ETC.)
(WATERWAYS, BUFFERS INCLUDING RIPIARIAN BUFFERS, FILTER STRIPS, TERRACES, CRP). USE 12' WIDTH FOR TERRACES (LF*12/43560=ACRE). USE 40' WIDTH FOR ALL OTHER PRACTICES REPORTED IN LINEAR FEET (LF*40/43560=ACRE). TREE PLANTING: ALL CONSERVATION PRACTICES THAT INCLUDE TREE PLANTINGS. (WINDBREAKS, SHELTERBELTS, AGROFORESTRY)
Plant Growth
WETLANDS CREATED AND/OR RESTORED: ALL CONSERVATION PRACTICES THAT INCLUDE THE CREATION OR RESTORATION OF WETLANDS.
Spatial data
Residues CO2
CO2
Active SOM
CO2
CO2
Slow SOM
Passive SOM CO2 CO2
90 80
No-tillage
70
Conventional tillage
60 50 40
Process-knowledge
30 20 10
n B K e e nd nt uc Ke ky nt W u . L cky a S . fay Ch et t e ar le s Ho t on yt ev Ho i ll e yt ev Ho i ll e yt ev M i a n ll e ha tt W an oo st W er oo st W er oo st W er oo st er KB S Ak ro n Si dn ey
rif fi
e
ho
es rs Ho
G
G
rif fi
n
0
Long-term experiments
After: Easter et al. (2005)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known knowns • Estimates of soil organic carbon (SOC) stocks for the Brazilian Amazon obtained from different studies (Cerri et al. 2006, AEE subm.) Source
Soil layer (cm)
SOC stocks (Pg)
Moraes et al. (1995)
0-20
21
Batjes & Dijshoorn (1999)
0-30
25
Bernoux et al. (2002)
0-30
22.7 ± 2.3
Batjes (2005)
0-30
23.9 - 24.2
GEFSOC project* Century RothC IPCC
0-20 0-20 0-30
32.6 27.0 26.9
* Estimates for the year 2000 and includes land use changes and management practices
• Estimates of SOC stocks and changes remain fraught with uncertainty, irrespective of scale. This uncertainty should be quantified (Falloon and Smith, 2003).
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known knowns food
fiber
Soil
biomass
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
energy
Soil
?
Known knowns
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
energy Ethanol sugarcane
?
Known knowns Biodiesel
soybean
Castor-oil plant
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Global warming
?
Known knowns
CO2 Fotosynthesis
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known knowns
Biodiesel and the Carbon Cycle
Used or Waste Oil
Transesterfication Process
Oil Extraction and Use
CO2 in the Atmosphere Oil seed (ie. Canola)
Reduced Smog And CO2
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known knowns
CO2
+3,2 ± 0,1PgC yr-1
Preserving Biodiversity Combating land degradation
Improving soil quality Increasing soil productivity
Fossil fuel combustion
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known knowns
win-win scenario
CO2
+3,2 ± 0,1PgC yr-1
Preserving biodiversity Combating land degradation
Improving soil quality Increasing soil productivity
Fossil fuel combustion
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
biologically, it is most useful when it decays (Janzen 2006)
Emissions
Sequestration
Known knowns
Known knows….most known is
Soil organic matter is much more than a potential sink for storing excess CO2
?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
biologically, it is most useful when it decays (Janzen 2006)
Emissions
Sequestration
Known knowns
Known knows….most known is
Soil organic matter is much more than a potential sink for storing excess CO2
?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Known Knowns ?
Tropical Soils ? Known Unknowns
? Unknown Unknowns
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Global distribution of soil organic carbon: native condition
?
Known Unknowns
Tropical ecosystems ~ 26% or 180 Pg
WRI, 2000 (FAO, 1995 & Batjes, 1996)
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Known Unknowns
Soil C Known
Slash & burn
Crop/Pasture installation
?
Soil C
Unknown
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Global distribution of soil organic carbon:
Organic carbon kg.m-2
anthropgenic use
180 Pg C
+∆ or
-∆
?
Known Unknowns
?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Carbon sequestration/GHG: full account
?
Known Unknowns
Example of N2O
100 Kg N ha-1 1.25 kg N-N2O 1 year
Soil C
Soil C
1.96 kg N2O x 296 (GWP) = 580 kg CO2eq
↓
158 kg Ceq ha-1 yr-1
∆ C > 158 kg ha-1 yr-1 to have a benefit N2O emissions can be greatly influenced by land management and difficult to predict
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions SOC origin
?
Known Unknowns
One origin
Soil Carbon stock Remaining from native ecosystem DEFORESTATION
Time
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Known Unknowns
2
CO2
?
N 2O
Forest Slash Burn Dense Cerrado Cerrado In soil: Savanna Organic matter dynamic C and N stocks Agregation Structure δ 13C Functional diversity
CH4
Pasture
Agriculture
Main culture Soybean Rice Cotton Maize
Succession Fallow Millet Sorgum Pasture/crop
Management Conventional Conservative
Social and economic consequences
Population Income distribution Eduaction Health Sanitation
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Known Knowns ?
Tropical Soils ? Known Unknowns
? Unknown Unknowns
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Unknown Unknowns
The most difficult part!!
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Unknown Unknowns
Biotechnological improvement
Is it possible to enhance C sequestration by changing soil microorganisms, plant biochemistry and/or belowground allocation by plant? Do we know all about those??
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Do we know all about plant??
?
Unknown Unknowns
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Unknown Unknowns
Feedbacks Example
Plant and Soil
How will global warming, through its effects on carbon inputs (quantity and quality) and soil C mineralization, affect soil C stocks ?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions Adding residue and N stimulated fungi which seemed to have Inhibited C mineralization……Why?
CO2
?
Unknown Unknowns
CO2
Plant C Fungi
SOM
Rice et al 2006
CT
NT
Fungi SOM Enhanced Aggregation
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
?
Unknown Unknowns
Food Security How will future “soil C sequestration/greenhouse gas emissions” impact on food security and livelihoods?
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas (GHG) Emissions
TOPICS General Considerations Importance of soil organic carbon Carbon balance and sequestration The tropics Carbon sequestration and international effort
Soil Organic Carbon / GHGs in the tropics Known knows Known unknowns Unknown unknowns
Final Considerations
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Knowledge of SOC stocks and changes is needed to devise plans for:
• The sustainable management of ecosystems •The mitigation of GHG emissions •The likely impacts of climate change on soils/ecosystems in the future
Soil Organic Carbon Stocks/Sequestration and Greenhouse Gas Emissions
Our grandchildren still have problems to study…