1. Climate Change Mitigation Potential of Biochar:
A Review and Framework for Carbon Accounting
Master’s Project presented by John Swanson
Advisor: Dr. Daniel Richter
Good morning. My name is John Swanson and my presentation today is on the climate change mitigation potential of biochar. My study is comprised of a review and analysis of the scientific literature on this topic, and my paper includes a recommended framework for carbon accounting for biochar projects.

2. Outline Prologue: Climate Change What is Biochar? Study Methods
Biochar Background
Biochar Project Types
The Climate Mitigation Potential of Biochar
Current Market Incentives
A Carbon Accounting Framework for Biochar
Conclusions
This is an outline of my presentation today. It includes introductory information on climate change as the context for my study, An introduction to biochar, The methods for my study, Background information on biochar, Biochar project types, The climate change mitigation potential of biochar on a global scale, Current market incentives and their affect on biochar implementation, a recommended carbon accounting framework for biochar, and conclusions.

3. Prologue: Climate Change
Lower atmosphere and oceans are warming
No natural occurrences (e.g. increased solar irradiance) can account for recent changes
Climate change is one of humanity’s greatest challenges. There is now wide agreement within the scientific community that the lower atmosphere and the oceans are warming, and that this is causing changes in the earth’s climate systems. Average temperatures and climate have changed over earth’s history, however, the general consensus among researchers today is that there are no naturally occurring phenomena that can account for the changes observed over the last 150 years.

4. Prologue: Climate Change
Combustion of fossil fuels (coal, petroleum, natural gas) is primary cause
Has caused increases in heat- trapping greenhouse gases (carbon dioxide, methane, nitrous oxide and some halocarbons)
Increases radiative forcing
Most scientific organizations regard the combustion of fossil fuels as the primary driver of climate change. The use of fossil fuels over the last century, and contributions from other industrial processes has caused increases in the tropospheric concentrations of heat-trapping greenhouse gases. These gases include carbon dioxide, methane and nitrous oxide, as well as some halocarbons. These gases prevent radiant heat from escaping to the upper atmosphere.

5. Prologue: Climate Change
Anticipated effects of climate change include changes in weather patterns, storms, drought
Affects human habitation, agricultural systems, ecosystems and species (extinctions).
Areas of recent exceptional drought in Texas; The Brazos River is running dry.
The anticipated effects of climate change include changes in weather patterns and regional climate, increased severe weather events including storms and droughts, adverse effects on human habitation, agriculture, ecosystems, and species extinctions in affected areas. The frequency and severity of such climate events are affected by increased concentrations of greenhouse gases in the atmosphere.

6. Prologue: Climate Change
Polar ice and glaciers receding
Sea levels rising
Climate change is also causing arctic sea ice to recede at an increasing rate. Sea level rise from thermal expansion of ocean water and the melting of land based ice sheets and glaciers is also occurring. A rise in mean sea level of over three feet is expected this century. Sea level rise of that magnitude would result in catastrophic damage to coastal areas from flooding due to storm surges and high tide events.
Marshall Islands high tide, 2011
Hurricane Sandy storm surge inundating New Jersey Coastline, 2012

7. Prologue: Climate Change
Policy and scientific responses: alternative energy, efficiency, carbon sequestration
Scientists and policy analysts have developed proposed responses to reduce net greenhouse gas emissions and limit the effects of climate change. These proposals include the use of alternative energy sources, energy efficiency measures for electricity demand and transportation, and the sequestration of carbon in living biomass, or below ground as stored gases. Such strategies are intended to reduce net greenhouse gas emissions from human activity and stabilize the concentration of these gases in the atmosphere.

8. Biochar Biomass deliberately charred and applied to soil -- Biochar
In recent years, the production and application to soil of charred or “carbonized” biomass has received increased interest as a technique that may have significant climate change mitigation potential. Charred material is generated when biomass is thermally decomposed in an oxygen-deficient atmosphere, which prevents complete oxidation of the biomass. Charred biomass that is deliberately incorporated into soil for long term carbon stabilization and soil amendment is typically referred to as biochar.

9. Study Methods Review scientific literature on biochar
Evaluate biohcar’s potential as a climate change mitigation tool
Analyze these characteristics in context of existing carbon market incentive programs
Produce a recommended framework for carbon accounting for biochar
The methods for my study included an examination of existing scientific literature on biochar’s history, characteristics, and its potential as a tool for offsetting GHG emissions. This study also provides an analysis of the incentives and structure of existing carbon markets and the degree to which they are useful for biochar projects. Additionally, a suggested framework for carbon accounting for biochar systems is provided to inform future analysis of biochar’s role in influencing GHG concentrations in the atmosphere.

10. Biochar Background Biomass has long been used for energy
Biomass combustion is carbon neutral
Fossil fuel combustion adds carbon to the cycle
Wood, agricultural waste, and manure have long been used as a source of energy. When biomass is combusted to produce heat or electricity, the energy released can be considered “carbon neutral,” because there is no net gain of carbon to the atmosphere; the organic carbon in the biomass fuel was originally captured from the atmosphere through photosynthesis, and would return to the atmosphere as carbon dioxide or methane if the biomass were left to decompose. Conversely, fossil fuel utilization removes paleo-carbon sequestered below ground for many millions of years, and through combustion, adds carbon to the atmosphere in the form of carbon dioxide and methane. However, if technologies such as pyrolysis or gasification are used, instead of combustion, to generate useable energy from biomass, biochar can be produced simultaneously.

11. Biochar Background Carbon-negative energy production,
multiple benefits from biochar
During biochar production, a portion of the biomass carbon is removed from the photosynthesis and decomposition cycle and can be stored for centuries in soil. As such, biochar-generating projects are considered carbon-negative energy systems, because carbon in the atmosphere is reduced, while simultaneously producing energy. Biochar also has the potential to yield additional environmental benefits. Biochar enhances soil’s desirable physical and chemical characteristics by retaining water and nutrients, which may reduce fertilization and irrigation requirements for agriculture. Biochar may also adsorb pesticides, nutrients and minerals in soil, preventing the movement of these chemicals to surface water or groundwater. Biochar can also reduce methane and nitrous oxide emissions from agricultural soils, which could have additional climate mitigation effects. These benefits have economic value in addition to the sequestration of carbon. Recent assessments indicate that well-managed biochar projects could play a significant role in reducing net greenhouse gas emissions.

12. Biochar Background Biochar from fire is naturally occurring
5-15% (or more) of North American prairie soil
Australia, Africa, South America
Biochar is very stable
Natural Australian soil char 1,300-2,600 yrs old
Man-made Amazonian biochar 600-8,700 yrs old
Far more stable than original biomass
Presence and age in existing soils
Resistance to decomposition in soil in laboratory incubation, compared to biomass
Biochar in soil is naturally occurring. One study estimated the char content of north American prairie soil at 5-15% from natural wildfires. Char in soil is very stable and has been carbon dated in soils up to 8,700 years. A lab study also demonstrated a lack of microbial decomposition of biochar in an incubated soil sample after 500 days. These studies demonstrate biochar’s extraordinary resistance to microbial decomposition, also known as “recalcitrance” in two ways: its presence and age in existing soils, and it’s resistance to microbial breakdown under controlled laboratory conditions.

13. Biochar Project Types Terra Preta in the Amazon Basin
Ancient technique
Supported vast communities
Could be duplicated in industrialized countries or developing nations (slash-and-char vs. slash-and-burn)
Recent interest in biochar has been stimulated by the discovery that biochar is the primary reason for the highly fertile dark earths in the Amazon Basin known as Terra Preta de Indio, or simply terra preta. Amerindian populations began deliberately enriching broad areas of the basin that were used for agricultural production with char and ash prior to the arrival of Europeans. Researchers speculate that pre-Columbian natives learned that additions of charcoal increased the fertility of these soils and the longevity of production that could be obtained from an area cleared of natural vegetation. The fact that these soils 1000 years hence retain both their enhanced fertility and their charcoal material, has spurred great interest in studying and recapturing the benefits of this land management approach.

14. Biochar Project Types Modern techniques
Pyrolysis, gasification (also torrefaction, flash carbonization, hydrothermal carbonization)
Fast pyrolysis: 13% syngas, 75% oil, 12% char
Slow pyrolysis: 35% syngas, 30% oil, 35% char
Gasification: % syngas, 5% oil, 10% char
Historically, char and charcoal were produced using pits or brick kilns. Modern techniques can produce char with fewer emissions of particulates or smoke. Pyrolysis is the thermal decomposition of organic material in the absence of oxygen and is also an initial stage in both combustion and gasification. One can manage the temperature and exposure time of the biomass to the heat to achieve desired ratios of three end products: syngas (a combustible mixture of hydrogen, hydrocarbons, and other gases), bio-oil and char. Fast pyrolysis, slow pyrolysis and gasification can be used to produce different amounts of these products. Syngas can be combusted to generate electricity for on-site use or connection to a power grid. Bio-oil can be combusted or refined for use as a transportation fuel, but the refining process is atypical compared to petroleum oil, affecting its feasibility as a fossil fuel substitute.

15. Climate Mitigation Potential of Biochar
Studies of annual global mitigation potential
Woolf (2010): 1.8 Pg C annually (12% of anthropogenic emissions)
International Biochar Initiative: 0.2 to 2.0 Pg C/yr
Nicholas Institute: Pg C/yr in U.S. agriculture
Terra Preta soil – 250 Mg/ha
Non Terra Preta soil – 100 Mg/ha
Above ground biomass – 110 Mg/ha
Productivity improvements variable and not fully characterized
Several studies estimate the potential climate mitigation benefits of biochar projects. These studies model the quantities of GHG offsets that can be obtained from biochar projects annually in terms of the mass of carbon, either in avoided carbon dioxide emissions, or as sequestered carbon. The scenarios use assumptions regarding the efficiency of a chosen system, the mass of sustainable biomass feedstocks available, and the presumed presence or absence of offset benefits in addition to sequestration. One study estimated sustainable biochar offset potential at 1.8 Pg annually. A Pg is equal to 1 billion metric tons. This represents approximately 12% of anthropogenic fossil fuel emissions. A study by the IBI found a range of 0.2 to 2.0 Pg in offsets or avoided emissions, under several sets of assumptions. The Nicholas Institute at Duke University estimated a potential of about 0.18 Pg just from US agricultural projects in a comparison of techniques using modified agricultural practices. Other studies considered the rates at which biochar could be applied to soil without adverse agronomic impacts. Terra preta soils contain up to 250 Mg (metric tons) carbon/ha compared to adjacent tropical soils at 100 Mg/ha. The terra preta exceeds the carbon content of above ground tropical forest biomass, estimated at 110 Mg/ha. Several studies exhibited increased agricultural productivity with biochar additions, but some studies exhibited no increases, or in some cases decreases, in production. The differences are likely due to variables in the makeup of the soil, the char, climatic conditions, and the plant species. Researchers agree that these relationships are not yet fully characterized and deserve further research.

16. Current Carbon Market Incentives
Regulatory
Clean Development Mechanism (Kyoto)
European Emissions Trading Scheme
California Cap-and-Trade
Voluntary
Verified Carbon Standard
Climate Action Reserve
American Carbon Registry
Biochar not currently included
Currently, there are no carbon markets that offer carbon offset credits or other financial compensation for the carbon sequestration or soil emissions suppression of biochar applied to soil. Major regulatory carbon market systems include the Clean Development Mechanism, the European Union Emissions Trading Scheme, and the California Cap and Trade market. Significant voluntary markets also exist, including the Verified Carbon Standard, the American Carbon Registry, and the Climate Action Reserve, but these, likewise do not accept biochar projects as a carbon offset protocol at this time. Forestation, agricultural projects, alternative energy and efficiency programs account for most offset protocols that are currently allowed under these programs.

17. Current Carbon Market Incentives
Protocol proposed
Could be developed
Would have to meet program criteria:
Additionality,
Permanence
Verifiability
Ownership
Quantification
One offset protocol for biochar projects has been published for consideration, and some biochar advocates promote the benefits of approving biochar protocols for use within the carbon markets. In particular, the CAR and ACR have ongoing evaluation and approval programs for new protocols, and have a demonstrated willingness to adopt additional methods. Approved protocols within these markets typically include criteria for establishing the additionality, permanence, verifiability, ownership, and quantification of carbon offsets. Proposed offset protocols for biochar would need to address these criteria.

18. Current Carbon Market Incentives
Limitations:
CA: Pg C/yr to 2020
EU ETS: Pg C/yr to 2020
Together = 5% of global potential if all offsets were from biochar
Other incentives: tax breaks, subsidies
Some systems will be self-sustaining
Even if biochar project protocols were approved for these markets, there are limitations to the total amount of biochar that could be counted under an offset program. The regulatory carbon markets require the emitters of greenhouse gases to significantly reduce emissions, and the programs limit the amount of carbon offsets that can be used for compliance under the emissions caps. For example, in the California market, individual entities are allowed to use offsets to comply with up to 8% of their total emissions limit. This limits the total amount of offsets allowed to be used for compliance in CA to about Pg/yr C, on average through The EU ETS allows about Pg C/yr through 2020 within the European market. Assuming all offsets came from biochar projects, this only supports 5% of biochar’s global estimated potential. This does not mean that biochar offset protocols could not play a role in climate change mitigation. However, it does demonstrate that the financial incentives of existing markets are limited, and these markets alone cannot maximize the global potential of biochar to offset GHG emissions. To maximize biochar’s potential, many projects would have to obtain revenue from alternative policy incentives or be self-sustaining.

19. A Carbon Accounting Framework
Biochar seems to be a tool worth pursuing
May occur in multiple sectors to varying extent
4 Gasifiers in CA currently, 1 under construction; numerous unmonitored farm-scale systems in U.S. and globally
A framework and database for carbon accounting for projects would be desirable
It’s likely that adoption of biochar systems will occur in multiple sectors and to varying extents, because the systems serve to address different objectives on different scales. Ongoing research may encourage a large number of small, widely-distributed electrical generation stations that produce biochar, using locally-available biomass. New projects could also emerge in the form of larger-scale, grid-connected bioenergy plants using, for example, biomass from forest thinning, or municipal green waste. There are several pilot scale gasification projects currently in CA. 2 are producing grid-connected energy, and there is one larger plant under construction. If biochar projects are developed outside carbon markets, alternative carbon accounting methods and databases may become important to evaluate the climate effects and other costs and benefits of these systems.

20. A Carbon Accounting Framework
The amount of biochar produced over time.
Carbon content of the biochar
Labile (volatile or easily decomposed) and recalcitrant fractions of the biochar
The disposition of the biochar after production
Information on the feedstock: composition, source, location of origin, sustainability
Quantitative information on the disposition of the energy produced
Lifecycle energy inputs used to produce the feedstock
Characteristics of the soil to which biochar is applied
Ideally, to capture information across all project types, a registry with data collection methods and project parameters would be established. The critical information needed to assess the impacts of a biochar project include The amount of biochar produced over time. Information on the carbon content of the biochar. The labile and recalcitrant fractions of the biochar. The disposition of the biochar after production. Information on the feedstock to assess lifecycle emissions of the produced material. Information on the disposition of the energy produced and the sources of energy that would be offset by the project. Ideally – if available – information on the lifecycle energy inputs used to produce the feedstock. And the characteristics (before and after) of the soil to which biochar is applied, to assess soil carbon stocks, plant productivity, and other offset characteristics.

21. A Carbon Accounting Framework
Recommended list of parameters
Char chemistry (pH, metals, dioxins, PAH, etc.)
Char physical parameters (CEC, surface area, etc.)
Char production characteristics (feedstock, temperature, process, etc.)
Char disposition and application (location, application rate, soil type, etc.)
Quantified soil characteristics of soil before and after application
In the written portion of my project, I have listed parameters that could be recorded in a database for further evaluation. The measurement parameters are not meant to represent a comprehensive set of data for tracking projects, but rather a starting point for further consideration. They include (read…). If such information were saved to a database, the information from multiple projects could be used to develop models, or to estimate GHG mitigation effects. Not all parameters will necessarily be tracked by all projects, because there is no centralized oversight entity for all biochar projects. However, available data could be used to analyze relationships. For example, if the recalcitrance of biochar associated with specific measured conditions is demonstrated, estimates of the sequestration potential across multiple projects could be calculated.

22. Conclusions Biochar must play a role in climate change mitigation
Biochar projects have the potential to feasibly/sustainably offset >1 Pg (1 billion tons) of CO2 carbon equivalents annually
Current carbon market incentives are not sufficient to rapidly increase or maximize the initiation and development of biochar projects
Based on the foregoing information I developed 8 conclusions. 1st biochar must play a role in climate change mitigation. The stabilization of biomass to biochar under sustainable protocols is not only an interesting idea; it is likely that this approach will be an imperative component in a multi-phased strategy to reduce and offset GHG emissions on a global scale. Biochar production is arguably the only currently known, economically feasible method for reducing carbon dioxide concentrations in the atmosphere on centennial to millennial time scales. GHG concentrations that may cause serious or even catastrophic climate change impacts are likely to be reached, or may already be present. In addition to reductions in fossil fuel emissions, the removal of carbon from the atmosphere, and its sequestration on centennial or millennial time scales will be required if climate impacts are to be mitigated. #2. Its relatively certain that biochar projects could be scaled in number to effectively sequester or offset 1 Pg of carbon annually. This exceeds the potential of afforestation. #3 Current carbon markets cannot provide sufficient incentives to maximize biochar’s potential

23. Conclusions
Other financial incentives could be used to accelerate the implementation of new projects.
Incentives should be prioritized for initiation of projects with greatest mitigation or economic potential
Uncertainty regarding recalcitrance in soil should not inhibit efforts for project initiation and development
4th, while offset protocols and carbon markets may be used to spur investment in biochar, the current markets will not maximize its potential. Some biochar projects may be self-sustaining without public incentives if energy production is profitable, or the other benefits of the char are monetized. However, subsidies, grants or other incentives could accelerate the initiation of projects with desirable characteristics. 5th, The potential climate change mitigation effects and economic benefits of biochar projects are not equal across all project types and circumstances. Systems that carry the greatest carbon offset potential based on reasonable project life cycle analyses, and those projects that are likely to achieve sustainable environmental and economic co-benefits should receive the highest prioritization with regard to distribution of limited financial assistance. 6th, Uncertainty regarding the recalcitrance of biochar in soil should not inhibit efforts for project initiation and development. Instead, the ongoing acquisition of data from multiple projects should inform biochar project carbon accounting. It is relatively certain that biochar additions to soil will sequester significant amounts of carbon for >100 years.

24. Conclusions
Biochar projects should be pursued despite conditions that may favor biomass combustion
A comprehensive carbon accounting system should be developed to evaluate global impact of biochar projects on net greenhouse gas emissions and climate.
7th, Biomass combustion for energy generation may achieve considerable emissions offsets, approaching those of biochar systems, and some considerations may favor these systems. However, biomass combustion does not achieve the biochar co-benefits of 1) soil amendment, 2) reduction in emissions from soil of CH4 and N2O, 3) surface and groundwater quality improvement, 4) indirect reductions in GHG emissions associated with lowered agricultural irrigation and fertilizer use, and 5) most importantly, removal of carbon from the atmosphere. Finally, Biochar may become a significant wedge against climate change. A carbon accounting system for biochar that is not otherwise tracked would greatly benefit the analysis of biochar’s climate change mitigation effects.

25. Biochar