Terrestrial Carbon Sequestration Jay Angerer Texas AgriLife Research Blackland Research and Extension Center September 3, 2010

Outline Introduction Introduction Global Carbon Cycle Global Carbon Cycle Plant processes Plant processes Terrestrial Sequestration Terrestrial Sequestration Forests Forests Cropland Cropland Rangeland Rangeland Disturbed or denuded land Disturbed or denuded land

Outline (cont.) Other Benefits Other Benefits Potential Pitfalls Potential Pitfalls Monitoring and Measurement Monitoring and Measurement Decision Support Tools Decision Support Tools

Where Does Terrestrial Sequestration Fit? From:

Terrestrial Carbon Sequestration Defined From Lal et al. (2004): From Lal et al. (2004): “Carbon sequestration implies transferring atmospheric CO2 into long-lived pools and storing it securely so it is not immediately reemitted. Thus, soil C sequestration means increasing Soil Organic Carbon (SOC) and Soil Inorganic Carbon (SIC) stocks through judicious land use and recommended management practices (RMPs).”

Global Carbon Cycle From:

Plants as “Injectors” From:

Local Carbon Cycle From: Photosynthesis

Photosynthetic Pathway Differences C 3 Pathway – better able to acquire CO 2 with increasing CO 2 (fertilizer effect) Rice, barley, wheat, most trees C 4 Pathway – CO 2 is “pumped” into inner leaf cells to reduce water loss. Does not respond as much to increasing CO 2 May be beneficial to C sequestration in hot, dry environments Corn, tropical grasses From: geos462/14rockvarnish.html

Pathways of Terrestrial Carbon From Lal et al Science 304, 1623

Carbon Sequestration: Forests Reforestation – replanting areas where trees have been removed Afforestation – planting trees in cropland Increasing tree growth – increase biomass of tree species Increasing permanence of forest products – reduce “throw-away” tendencies Decreasing the loss of current forested areas

Carbon Sequestration Rates and Saturation Periods: Forests From:

Forest Carbon Sequestration Programs Reforestation of degraded lands with fast growing tree species Reforestation of degraded lands with fast growing tree species Urban tree planting Urban tree planting Fire management of forests and surrounding areas Fire management of forests and surrounding areas Change other management practices (e.g. logging procedures) Change other management practices (e.g. logging procedures)

Cropland Carbon Sequestration Changes in crop management Changes in crop management No-till No-till Minimum-till Minimum-till Conversion to grassland Conversion to grassland Manure management Manure management Fertilizers Fertilizers Irrigation Irrigation Increased use of legumes Increased use of legumes

Carbon Sequestration Rates and Saturation Periods: Ag Lands From:

Soil Carbon Dynamics In Response To Tillage SOIL CARBON (% OF ORIGINIAL) IN RESPONSE TO CULTIVATION 1 50 SOIL CARBON Plowing Perennial Vegetation years Conservation Tillage 50

Factors Affecting Sequestration Soil texture (sand, silt, clay percentages) Soil profile characteristics (depth, rocks) Climate (temperature, humidity, rainfall) Rates can range from: 0 to 150 kg C/ha per year in dry and warm regions 100 to 1000 kg C/ha per year in humid and cool climates From: Lal et al Science 304, 1623

Potential Losses Soil Erosion Soil Erosion Removal of residues and mulch can increase erosion Removal of residues and mulch can increase erosion Deposition in channels or in aquatic systems Deposition in channels or in aquatic systems Deposition is 0.4 to 0.6 Gt C/year 0.8 to 1.2 Gt C/year is lost to exposure to atmosphere Must assess carbon used for crop management Plowing Fertilizer application Chemical Use These must be accounted for to get the proper offset From: Lal et al Science 304, 1623

Biochar for Improving Ag Soils Fine grained, highly porous charcoal Fine grained, highly porous charcoal Used as a soil amendment which improves soil physical and chemical properties Used as a soil amendment which improves soil physical and chemical properties Can increase site productivity Can increase site productivity First used by Amazonian natives First used by Amazonian natives

Rangeland Carbon Sequestration Rangelands are generally characterized as grasslands or shrublands that are not suitable for consistent crop production Rangelands are generally characterized as grasslands or shrublands that are not suitable for consistent crop production Occupy almost 50% of worldwide land area Occupy almost 50% of worldwide land area Carbon sequestration would require changes in grazing management Carbon sequestration would require changes in grazing management Reduced stocking rate or livestock removal Reduced stocking rate or livestock removal Grazing systems Grazing systems

Rangeland Carbon Sequestration Improved resource management Reduce wildfires Reduce wildfires Reduce water and wind erosion Reduce water and wind erosion Restore overgrazed and denuded areas Restore overgrazed and denuded areas Conversion of cropland to grazingland Conversion of cropland to grazingland Introduce/promote nitrogen fixing legumes Introduce/promote nitrogen fixing legumes

Carbon Sequestration Rates and Saturation Periods: Rangelands From:

Issues with Rangeland Carbon Sequestration Large land area, but relatively low carbon storage Large land area, but relatively low carbon storage In US, most rangelands are privately owned or are public lands (e.g. BLM land) In US, most rangelands are privately owned or are public lands (e.g. BLM land) High degree of uncertainty in sequestration estimates for most regions High degree of uncertainty in sequestration estimates for most regions Need large land areas to be attractive to potential buyer or as an offset Need large land areas to be attractive to potential buyer or as an offset May require development of government programs for assisting farmers/ranchers in joining carbon sequestration programs May require development of government programs for assisting farmers/ranchers in joining carbon sequestration programs

Assessing Carbon Sequestration Potential for Programs

Sequestration Potential for Southwest Region

Uncertainty Analysis Uncertainty in prediction of carbon sequestration on agricultural lands can be high, especially on rangelands Uncertainty in prediction of carbon sequestration on agricultural lands can be high, especially on rangelands Lack of quantitative information on carbon sequestration for various practices and locales Lack of quantitative information on carbon sequestration for various practices and locales Models need to be calibrated to these conditions Models need to be calibrated to these conditions An uncertainty analysis was conducted using carbon modeling results for southwest region An uncertainty analysis was conducted using carbon modeling results for southwest region

Assessing Uncertainty for Southwest Region The estimated amount of carbon sequestered and its associated uncertainty were mapped The estimated amount of carbon sequestered and its associated uncertainty were mapped A weighted averaging procedure was used based on soil texture, soil map unit, major land resource area, and county. A weighted averaging procedure was used based on soil texture, soil map unit, major land resource area, and county. Spatially explicit maps of the carbon sequestered and uncertainty were produced Spatially explicit maps of the carbon sequestered and uncertainty were produced

Sequestration on Disturbed Lands Issues affecting carbon Issues affecting carbon Exposure of soil Exposure of soil Water Erosion Water Erosion Wind Erosion Wind Erosion Carbon depleted to point where soil amendments may be required Carbon depleted to point where soil amendments may be required

Sequestration on Disturbed Lands Degraded or denuded land offers opportunity to replace/sequester carbon Degraded or denuded land offers opportunity to replace/sequester carbon Fast growing tree species Fast growing tree species Grasses or grass/legume mix Grasses or grass/legume mix Biochar? Biochar?

Potential Sequestration Rates From: Lal et al Science 304, 1623

Other Benefits of Terrestrial Sequestration Improved Ecosystem Services Improved Ecosystem Services Cleaner water Cleaner water Cleaner air Cleaner air Improved soil fertility Improved soil fertility Improved biodiversity Improved biodiversity Potential for monetary benefits Potential for monetary benefits Carbon trading/offsets Carbon trading/offsets

Pitfalls Interactions with biofuel production Interactions with biofuel production Land areas may be used for biofuel production rather than C sequestration Land areas may be used for biofuel production rather than C sequestration Implications for food security/livelihoods Implications for food security/livelihoods In the case of livestock producers, may reduce land available for grazing In the case of livestock producers, may reduce land available for grazing Increasing population may drive land use change to meet food security needs and negate carbon gains Increasing population may drive land use change to meet food security needs and negate carbon gains

Pitfalls Leakage Leakage The IPCC Special Report (2000) defines leakage as "the unanticipated decrease or increase in greenhouse gas (GHG) benefits outside of the project's accounting boundary as a result of project activities." The IPCC Special Report (2000) defines leakage as "the unanticipated decrease or increase in greenhouse gas (GHG) benefits outside of the project's accounting boundary as a result of project activities." Example: For a forest under a C sequestration program, logging may be displaced to an area outside the Project area. The CO 2 emissions that result from the displaced logging could partially or completely negate the benefits of avoiding CO 2 emissions in the protected forest. Example: For a forest under a C sequestration program, logging may be displaced to an area outside the Project area. The CO 2 emissions that result from the displaced logging could partially or completely negate the benefits of avoiding CO 2 emissions in the protected forest.

Monitoring and Verification Monitoring Monitoring Are (or where) the contracted practices being applied? Are (or where) the contracted practices being applied? Verification Verification Are the contracted practices sequestering carbon Are the contracted practices sequestering carbon Evaluation Evaluation Is their leakage? Is there proper accounting? Is their leakage? Is there proper accounting? Reporting Reporting Is the project meeting contract goals? Is the project meeting contract goals?

Monitoring and Verification Generally need to sample large area in multiple places to get a reasonable representation of carbon amounts Generally need to sample large area in multiple places to get a reasonable representation of carbon amounts Rangelands with non-uniform vegetation and terrain require more sampling Rangelands with non-uniform vegetation and terrain require more sampling Samples using conventional lab analyses are expensive to process Samples using conventional lab analyses are expensive to process Terrestrial sequestration verification would be too expensive to do with conventional methods. Terrestrial sequestration verification would be too expensive to do with conventional methods.

Measurements of Soil Carbon Develop improved technologies and systems for direct measurements of soil carbon Develop improved technologies and systems for direct measurements of soil carbon Two Methods Two Methods Laser induced breakdown spectroscopy (LIBS) Laser induced breakdown spectroscopy (LIBS) Near Infrared Reflectance Spectroscopy (NIRS) Near Infrared Reflectance Spectroscopy (NIRS) Allow rapid scans of samples in the field Allow rapid scans of samples in the field Examine correlation of results with other technologies Examine correlation of results with other technologies Principles for cost effective sampling Principles for cost effective sampling

LIBS System

Portable NIRS System

Simulation Models and Decision Support Tools Models can be used to assess carbon sequestration potential for a given area Models can be used to assess carbon sequestration potential for a given area Provide the ability to examine different management alternatives for carbon gain Provide the ability to examine different management alternatives for carbon gain Allow examination of other outputs such as erosion and water quality under the selected practice Allow examination of other outputs such as erosion and water quality under the selected practice

Simulation Models CENTURY Model CENTURY Model Model and Documentation Model and Documentation Online tool: Online tool: APEX and EPIC Model APEX and EPIC Model COLE (Carbon OnLine Estimator): Web-based Tool for Forest Carbon Analysis COLE (Carbon OnLine Estimator): Web-based Tool for Forest Carbon Analysis

Carbon Decision Support Tool

Homework Read two journal articles: Read two journal articles: Soil Carbon Sequestration Impacts on Global Climate Change and Food Security Soil Carbon Sequestration Impacts on Global Climate Change and Food Security R. Lal (11 June 2004) Science 304 (5677), Soil carbon sequestration to mitigate climate change and advance food security. R. Lal, et al. Soil Sci 172 no12 D 2007

Questions?