The production and application of biochar into soils could contribute to climate-change mitigation in different ways and therefore carbon markets are one option to channel funding to biochar projects. To become accepted, biochar advocates will have to address the
following aspects:
x sustainability issues;
x public perception issues;
x additionality;
x proof of permanence;
x leakage;
x recognised carbon accounting, validation; monitoring, reporting, and verification methodologies; and
x compatibility with other type of credits.
Sustainability issues
All projects in carbon markets should promote sustainable development. If negative consequences are likely to arise, then project developers must take them into account and avoid them. Depending on specific local conditions, biochar projects may have detrimental effects on biodiversity and local populations due to the change of land use and crop
production choices, which could result in social conflict (Ernsting and Smolker, 2009).
Public perception issues
Public perception is an essential factor to consider when developing a carbon project. Stakeholder meetings should take place prior to the commencement of any carbon project in order to collect and consider feedback from the community involved. Attitudes toward
63 biochar are divided and can play a major role in the acceptance of biochar. Biochar
advocates and pyrolysis companies push for the inclusion of biochar in carbon markets, whereas civil and non-governmental groups have signed a declaration to “keep biochar and
soils out of carbon trading” (Rainforest Rescue, 2009). This declaration was signed by approximately 150 organisations. A Biofuelwatch briefing paper states (Ernsting and Smolker, 2009):
“Lobbying is underway for a massive scaling up of biochar production, and yet there is
little to substantiate the many proclaimed benefits. It is critical that we address this issue with caution, especially given the many dire consequences associated with any technology that involves large biomass demand and manipulation of poorly understood soil
ecosystems!”
Additionality
A project in carbon markets is additional if GHG emissions are reduced below those that would have occurred in a baseline scenario. On the one hand, studies have claimed that the economic viability of biochar projects highly depends on the revenue from carbon finance (Gaunt and Lehmann, 2008; McCarl et al., 2009; Roberts et al., 2010) suggesting their additionality. On the other hand, others claim that a biochar scheme “would need no
subsidy: the farmer would make a profit” (Bruges, 2009, quoting James Lovelock, the
author of the Gaia Theory). Baum and Weitner (2006) declared that “production and
application costs of biochar may be fully recovered, even in the absence of a carbon market, based solely on crop production benefits and fertilizer cost savings”. Sohi et al.,
(2009) stated that “for any biochar scenario it is possible that the agronomic value for
biochar is sufficient to render the economic evaluation positive, without resorting to carbon
markets or Government incentives.” If these statements become reality and biochar turns out to be the powerful ingredient in soil management, then it should not be used as an additional permit to continue polluting through offsetting mechanisms.
Proof of permanence
Demonstrating permanence is a significant challenge for biochar projects. Concerning C sequestration in soils, the variation of labile fractions of different biochars under different soils and climates make it difficult to estimate an accurate stability of biochar. By
comparison, temporary credits from forestry projects have primarily seen action in the voluntary carbon markets and have been traded at a negligible value because of the lack of compatibility reduces their attractiveness (Ristea and Maness, 2009).
Leakage
In carbon markets, leakage is defined as the net change of anthropogenic emissions by sources of GHG which occurs outside the project boundary, and which is measurable and attributable to the project activity (UNFCCC, 2012a). This definition is open to
interpretation. It begs the question: ‘Who does the measuring and attribution, under whose
rules and why?’ Leakage, just as baseline and project scenarios, is a hypothetical concept. In practice, project developers appear to generally dismiss leakage on the basis that it is difficult to calculate (Boyd et al., 2007; Millard-Ball and Ortolano, 2010).
The displacement of biomass used for energy to produce biochar could be seen as leakage (Bruun and Luxhøi, 2008). Gaunt and Cowie (2009) suggested another type of leakage concerning the production of biochar from the removal of crop residues left on the ground, which deprives soil of C build up. Furthermore, GHG emissions related to land use change is another kind of leakage that a biochar project could cause. For example, Roberts et al. (2010) hypothesised that the diversion of annual crops to perennial grass energy crops for biochar production would cause land conversion to cropland to replace the crops lost to biochar feedstock, and this would reduce the climate change benefit of the biochar system.
Recognised carbon accounting, validation, monitoring, reporting and verification methodologies
Currently there are no approved carbon methodologies for biochar projects. Carbon Gold (2009), a British company, presented a general biochar methodology to the Verified Carbon
65 Standard (VCS), formerly the Voluntary Carbon Standard Association, but it did not pass its double approval process. During the call for public inputs, there were nine submissions from stakeholders including the New Zealand Biochar Research Centre.
GHG emissions that could be avoided in a baseline scenario due to the combustion of bio- oil and pyrolysis gas for energy production are eligible and therefore, do not face major methodological barriers in carbon markets. Emission reductions attributed to the
displacement of fossil fuels with liquid bio-oil produced from pyrolysis are accepted. If the pyrolysis gas and resulting heat are used to meet the energy needs of the pyrolysis plant, then the net GHG emissions associated to the combustion of the pyrolysis gas would be part of the project and would not represent any additional emission reductions. However, if the pyrolysis gas (or heat) is used to displace fossil fuels outside the project’s boundary, then these reductions can also be recognised. If the feedstock is hypothesised to decompose anaerobically in the baseline scenario (Gaunt and Cowie, 2009), then the amount of CH4
emissions avoided due to the production of biochar could also be claimed. Carbon accounting and monitoring methodologies for most of these activities are available at the CDM website.
Calculation of the emission savings that could be associated with the application of biochar into soils remain one of the greatest challenge that biochar faces in carbon markets. This is due to the large uncertainties concerning biochar-soil dynamics. Ogawa et al. (2006) and Gaunt and Cowie (2009) have highlighted the lack of methods for monitoring and verifying biochar projects.
Compatibility with other type of credits
The potential of biochar to sequester C in soils on a long-term basis has been explained (Lehmann, 2007). This form of C sequestration is rather unique and cannot be compared to other types of credits currently available in the market since it removes CO2 from the
atmosphere on a long-term basis. Some carbon credits refer to the avoidance of GHG emissions by displacing fossil fuels, whereas others stand for temporary C sequestration (e.g. forestry projects). The incompatibility between credits makes the price of temporary credits diminish (Ristea and Maness, 2009). Moreover, carbon credits issued to projects
concerning avoided deforestation are also different and compatibility is a major concern (Neeff and Ascui, 2009). Further consensus on the need to distinguish biochar from other types of carbon abatement technologies is required to address the issue of compatibility for biochar credits.