Terrestrial Carbon Sequestration Adrian Martin Global terrestrial C budgets Global terrestrial C budgets Historical C emissions from land use change Historical C emissions from land use change Global potential for LULUCF sequestration Global potential for LULUCF sequestration Reforestation Reforestation Managing agricultural lands Managing agricultural lands Institutional framework: Kyoto and CDM Institutional framework: Kyoto and CDM Social issues Social issues

IIED (2002)

Carbon cycling on land 270 PgC/yr dissolved in leaf water ~ 1/3 atmospheric C 120PgC/yr fixed through Photosynthesis = Gross Primary Productivity 60Pg/yr plant growth = Net Primary Productivity 60Pg/yr Respired by plants >½ directly released to atmosphere

60Pg/yr Net Primary Productivity Net Ecosystem Productivity Net Biome Production Releases through fire, harvests, soil erosion, … Heterotrophic respiration Bacteria, fungi Herbivores

Net Ecosystem Productivity Tropical Forests: MgC/ha/yr Tropical Forests: MgC/ha/yr Temperate forests: 0.8 – 7.0 MgC/ha/yr Temperate forests: 0.8 – 7.0 MgC/ha/yr Boreal forests: (<0?) – 2.5 MgC/ha/yr Boreal forests: (<0?) – 2.5 MgC/ha/yr (IPCC 2001)

Global C02 Budgets (PgC/yr) 1980s1990s Atmosphere Increase 3.3 ± ± 0.1 Emissions (fossil fuel, cement) 5.4 ± ± 0.4 Ocean-atmosphere flux ± ± 0.5 Land-atmosphere flux (net biome production) (net biome production) -0.2 ± ±0.7 - Land use change - Land use change Residual terrestrial sink - Residual terrestrial sink-1.9

Historical Losses of Terrestrial Carbon through Land Use Change Houghton (1990) estimates 121PgC lost 1850 – 1990 Houghton (1990) estimates 121PgC lost 1850 – 1990 De Fries et al (1999) further 60PgC lost prior to 1850 De Fries et al (1999) further 60PgC lost prior to 1850 Total 180PgC (280 from fossil fuels) Total 180PgC (280 from fossil fuels) Approx 40% of this in atmosphere Approx 40% of this in atmosphere Substantial (but ultimately limited) opportunities for modifying above and below ground carbon storage Substantial (but ultimately limited) opportunities for modifying above and below ground carbon storage

Deforestation (cont.) Deforestation responsible for estimated 90% of land use change emissions since 1850 Deforestation responsible for estimated 90% of land use change emissions since 1850 FAO (2001) Global Forest Resources Assessment 2000: FAO (2001) Global Forest Resources Assessment 2000: Gross annual loss : 14.6 million ha. Gross annual loss : 14.6 million ha. Net annual loss : 9.4million ha. Net annual loss : 9.4million ha.

Forest Area Changes TropicalNon-tropical Natural Forest (Million Ha) Plantation Forest (Million Ha) Source: FAO 2001 Main cause of loss in tropical areas: conversion to agriculture

Global Potential: LULUCF IPCC (1996 SAR) slowing deforestation and promoting reforestation could increase carbon stocks by 60-87PgC IPCC (1996 SAR) slowing deforestation and promoting reforestation could increase carbon stocks by 60-87PgC IPCC (2000 SRLULUCF) various management options could lead to global land-atmosphere flux of -1.3PgC/yr in 2010 and -2.5PgC/yr in 2040 IPCC (2000 SRLULUCF) various management options could lead to global land-atmosphere flux of -1.3PgC/yr in 2010 and -2.5PgC/yr in 2040 Plantations: Plantations: Coniferous AUS & NZ: 10 t/ha/yr Coniferous EUR & US: t/ha/yr Canada and former SU: 0.9 –1.2 t/ha/yr Tropical: 6.4 – 10 t/ha/yr

Biomass Litter/woody debris Soil Organic Matter Wood Products & Landfill Above Ground Below Ground Short Term Long Term Cultivated land Forest - Non-cultivated land Forest -? IPCC 2000 SRLULUCF, Table 3-6

Repositories for extra carbon storage in terrestrial ecosystems RepositoryFractionExamples Mean Residence Time (MRT) BiomassWoodyNon-woody Tree boles Crops/leaves Decades to centuries Months to years Soil organic matter LitterActiveStable Surface litter, crop residues Partially decomposed litter; carbon in macro-aggregates Stabilised by clay; chemically recalcitrant carbon; charcoal Months to years Years to decades Centuries to millennium ProductsWood Paper, cloth grainswaste Structural, furniture Paper products, clothing Food and feed grain landfill Decades to centuries Months to decades Weeks to years Months to decades

Predicted responses to different pools of soil organic matter for agricultural land converted to forest in northeastern United States of America (Gaudinski et al. 2000, in SRLULUCF)

Carbon sequestration through reforestation in the tropics 80 year average: 2.36Mg/ha/yr First 20 years: 6.17 Mg/ha/yr Silver et al (2000)

100 year average: 0.41 Mg/ha/yr First 20 years: 1.30 Mg/ha/yr Silver et al (2000)

Can sequestration continue beyond 80 years? One way is to harvest biomass for energy One way is to harvest biomass for energy The other is to ensure wood products have a long residence time The other is to ensure wood products have a long residence time Paper products like packaging, newspapers, magazines 0.5 Paper products like books 15 Furniture20 Fences, garden products etc 20 Railway sleepers, transmission poles 40 Timber in buildings 75 Average estimated lifetime of wooden products [Germany] Fruewald & Scharai-Rad (2000) NB The fate of stored carbon in wood products is poorly known

Changing agricultural practices for below ground carbon storage Historical loss of soil C through oxidation~ 50 PgC Historical loss of soil C through oxidation~ 50 PgC (Ingram & Fernandes, 2001) (Ingram & Fernandes, 2001) Average loss of carbon from top 100 cm of soil following conversion to agriculture = 15-40% Restoration possible through land use change and land management Global potential for C sequestration in agricultural soils PgC over years. (Paustian et al, 1997, cited in Ingram & Fernandes) Global sequestration from improved management of degraded lands 0.6 – 2 PgC/yr (Batjes, 1999, cited in Olsson & Ardo, 2002)

Carbon sequestration situation against soil organic carbon level. Source: Ingram & Fernandes (2001)

Main Issues Management Options Soil erosion (especially loss of clay content) Soil erosion (especially loss of clay content) Oxidation of carbon Oxidation of carbon Tillage Tillage Temperature (e.g. reduced canopy) Temperature (e.g. reduced canopy) Removal of organic residues Removal of organic residues Drainage (aeration) Drainage (aeration) No tillage No tillage Change of crops (raise NPP) Change of crops (raise NPP) Fertiliser Fertiliser Land use change – agroforestry, grassland Land use change – agroforestry, grassland Fallow with grasses/legumes Fallow with grasses/legumes Grazing of rangelands (see Schuman et al, 2002) Grazing of rangelands (see Schuman et al, 2002)

Olsson & Ardo (2002) case study from Sudan Modelling of 6 different management systems in Sudanese cropland Modelling of 6 different management systems in Sudanese cropland System Soil carbon in 2100 (gC m -2 ) No change 70 5:6 crop: fallow 115 5:10 crop: fallow 128 5:15 crop: fallow 163 5:20 crop: fallow 170 Grazing only 245

Institutional Basis Kyoto article 3 removals by sinks resulting from direct human-induced land-use change and forestry activities, limited to afforestation, reforestation and deforestation since 1990, measured as verifiable changes in carbon stocks in each commitment period, shall be used to meet the commitments under this Article…. Kyoto article 3 removals by sinks resulting from direct human-induced land-use change and forestry activities, limited to afforestation, reforestation and deforestation since 1990, measured as verifiable changes in carbon stocks in each commitment period, shall be used to meet the commitments under this Article…. Other sinks (such as agricultural soils may be included in the future) Other sinks (such as agricultural soils may be included in the future) 6 th COP (resumed July 2001) agreement that reforestation and afforestation allowed under Clean Development Mechanism. 6 th COP (resumed July 2001) agreement that reforestation and afforestation allowed under Clean Development Mechanism. CDM – allows developed countries to meet their own commitments by funding emission reduction or carbon sequestration projects in developing countries. CDM – allows developed countries to meet their own commitments by funding emission reduction or carbon sequestration projects in developing countries. Limited to 1% of a countrys baseline emissions (i.e. can meet about 20% of their reduction through CDM forestry projects). Limited to 1% of a countrys baseline emissions (i.e. can meet about 20% of their reduction through CDM forestry projects).

Eligible Land Use Activities in the CDM. Source: IIED 2002

Sequestration: a few concerns Verification issues and transaction costs Verification issues and transaction costs What kind of forestry? What kind of forestry? Large-scale? Large-scale? Monocultures Monocultures Fast-growing exotics? Fast-growing exotics? Whose development priorities? Whose development priorities? Will sinks solve the problem? Will sinks solve the problem? Global feedbacks Global feedbacks

FAO (2001) Global Forest Resources Assessment 2000, FAO (2001) Global Forest Resources Assessment 2000, Fruehwald, A. & Scharai-Rad (2000) Wood products as carbon sinks: a methodological approach, Fruehwald, A. & Scharai-Rad (2000) Wood products as carbon sinks: a methodological approach, IPCC (2001) Climate Change 2001: the scientific basis. IPCC (2001) Climate Change 2001: the scientific basis. IPCC (2000) Special Report on Land Use, Land Use Change and Forestry IPCC (2000) Special Report on Land Use, Land Use Change and Forestry IPCC (2001) Climate Change 2001: Mitigation. Section 4. Technological and Economic Potential of Options to Enhance, Maintain, and Manage Biological Carbon Reservoirs and Geo-engineering. IPCC (2001) Climate Change 2001: Mitigation. Section 4. Technological and Economic Potential of Options to Enhance, Maintain, and Manage Biological Carbon Reservoirs and Geo-engineering. IIED (2002) Laying the Foundations for Clean Development: preparing the land use sector: a quick guide to the Clean Development Mechanism, London: International Institute for Environment and Development, IIED (2002) Laying the Foundations for Clean Development: preparing the land use sector: a quick guide to the Clean Development Mechanism, London: International Institute for Environment and Development, Ingram, J. & Fernandes, E. (2001) Managing carbon sequestration in soils: concepts and terminology, Agriculture, Ecosystems and Environment, 87, Ingram, J. & Fernandes, E. (2001) Managing carbon sequestration in soils: concepts and terminology, Agriculture, Ecosystems and Environment, 87, Schuman, G., Janzen, H. & Herrick, J. (2002) Soil carbon dynamics and potential carbon sequestration by rangelands, Environmental Pollution, 116, Schuman, G., Janzen, H. & Herrick, J. (2002) Soil carbon dynamics and potential carbon sequestration by rangelands, Environmental Pollution, 116, Silver, W., Ostertag, R. & Lugo, A. (2000) The potential for carbon sequestration through reforestation of abandoned tropical agricultural and pasture lands, restoration Ecology, 8 (4), Silver, W., Ostertag, R. & Lugo, A. (2000) The potential for carbon sequestration through reforestation of abandoned tropical agricultural and pasture lands, restoration Ecology, 8 (4), Olsson, L. & Ardo, J. (2002) Soil carbon sequestration in degraded semiarid agro-ecosystems – perils and potentials, Ambio 30 (6), Olsson, L. & Ardo, J. (2002) Soil carbon sequestration in degraded semiarid agro-ecosystems – perils and potentials, Ambio 30 (6), Seely, B., Welham, C., Kimmins, H. (2002) Carbon sequestration in a boreal forest ecosystem: results from the ecosystem simulation model, FORECAST, Forest Ecology and Management 169, Seely, B., Welham, C., Kimmins, H. (2002) Carbon sequestration in a boreal forest ecosystem: results from the ecosystem simulation model, FORECAST, Forest Ecology and Management 169, Ridgwell, A., Maslin, M. & Watson, A. (2002) Reduced effectiveness of terrestrial carbon sequestration due to an antagonistic response of ocean productivity, Geophysical Research Letters, 29 (6), 19 Ridgwell, A., Maslin, M. & Watson, A. (2002) Reduced effectiveness of terrestrial carbon sequestration due to an antagonistic response of ocean productivity, Geophysical Research Letters, 29 (6), 19