Planting your way to net zero: Exploring Climate Active sequestration guidelines and FullCAM modelling - 100% Renewables

Planting your way to net zero: Exploring Climate Active sequestration guidelines and FullCAM modelling

In the ongoing effort to address climate change, there is little doubt that carbon sequestration through afforestation or reforestation can play a crucial role in a multifaceted climate change strategy. This approach involves planting trees and other woody vegetation to absorb and store carbon dioxide from the atmosphere.

Initiatives to sequester atmospheric carbon in woody vegetation can be incorporated into emissions reduction strategies either as carbon credit projects, for example through the Commonwealth Government’s Australian Carbon Credit Unit (ACCU) Scheme or, alternatively, as carbon insetting projects. Insetting refers to the practice of implementing carbon reduction activities directly within an organisation’s operational boundaries or value chain, rather than solely relying on traditional offset mechanisms typically managed by 3rd parties.

For organisations with suitable land under their management, insetting through tree planting can be a viable and practical option for reducing net emissions, with multiple benefits. Not only do trees provide a means to store carbon through the absorption of carbon dioxide during photosynthesis, but can support biodiversity, restore ecosystems, and enhance overall environmental health. Forests deliver essential ecosystem services such as shade, water regulation and soil protection, fostering ecological stability and climate change resilience, and can provide social and economic benefits. Recognised in global initiatives like the Paris Agreement, these strategies represent a vital component of comprehensive climate change strategies, aligning environmental, economic, and social objectives.

In this blog post, we will explore the topic of carbon sequestration quantification, together with an overview on the latest guidance provided by Climate Active and a look at the industry standard modelling tool called FullCAM.

Climate Active guidelines in the broader policy context 

The guidelines for incorporating carbon sequestration into a Climate Active carbon account are currently in development, with an anticipated finalisation date likely to be at the end of 2023 or early 2024. These guidelines are specifically designed for entities seeking to measure carbon sinks resulting from tree and shrub plantations, as part of their organisational carbon footprint calculations.

It is crucial to note that the Climate Active guidelines distinguish themselves from the Australian Carbon Credit Unit (ACCU) methods, which maintain their own set of rules for carbon credit projects. While there are similarities between the Climate Active guidelines and ACCU methods, the primary distinctions revolve around the starting and ending points of the processes.

Unlike ACUU methods, the Climate Active guidelines do not mandate that plantings be entirely new, nor do they generate ACCUs or any other tradable carbon credit unit. In cases where plantings are part of an ACCU Scheme project generating ACCUs, they cannot be accounted for using the Climate Active guidelines. However, entities have the option to employ voluntary cancellation of ACCUs to offset emissions.

Eligibility requirements for carbon sequestration

Entities interested in including tree planting activities in carbon footprint calculations must adhere to specific eligibility criteria. These criteria encompass a range of requirements, such as the need for plantings to fall within the operational control or supply chain of the entity, taking place in or after 1990, having a minimum plot area of 0.2 hectares, and being located in an area with FullCAM coverage. Additionally, the designated area must have remained free of forest cover for at least five years prior to planting, with no clearing activity having occurred in the five years preceding planting.

Moreover, the entity must plant species of trees capable of reaching a height of at least 2 meters and achieving a crown cover of at least 20% of the planting area. These species should either consist of native species to align with local vegetation or adhere to environmental planting specifications contained within ACCU methods.

Quantifying carbon sequestration with FullCAM

To model the abatement outcomes of tree planting activities with precision, Climate Active mandates the use of CSIRO’s FullCAM software. FullCAM, an acronym for “Full Carbon Accounting Model,” is a comprehensive tool developed by the Australian government’s Commonwealth Scientific and Industrial Research Organisation (CSIRO).

FullCAM’s capabilities encompass various facets of carbon accounting and modelling, including:

  • Inventory data: FullCAM relies on inventory data, encompassing factors like forest area, age, species composition, and other pertinent parameters, to create a comprehensive representation of the forest landscape.
  • Growth and yield models: These models simulate forest growth over time, considering species-specific characteristics, climate variations, and management practices to estimate biomass production accurately.
  • Upper age limits: FullCAM introduces upper age limits to ensure reliable sequestration estimates, with these limits differing for plantation forestry and environmental plantings.
  • Decomposition: FullCAM tracks the fall and decomposition of organic material, such as leaves and branches, offering estimates of the carbon released back to the soil and into the atmosphere over time.
  • Biomass and soil carbon: While the model calculates the movement and storage of carbon between biomass and soil “sinks”, only carbon sequestered in the vegetation’s trunks and branches is eligible for insetting.
  • Harvest and deforestation: In cases of forest harvesting or deforestation, FullCAM computes emissions arising from biomass removal.
  • Reporting: Calculated estimates can be employed for various reporting purposes, including carbon accounting, emissions trading schemes, or the monitoring of forest carbon balance.

Calculation of net emissions abatement

For carbon accounting purposes, the net carbon masses for each reporting period are calculated by subtracting the carbon stock at the beginning of the period from that at the end. Subsequently, this value is multiplied by a specific factor to obtain the corresponding net amount of sequestered CO2, which is then included in the carbon account. The Climate Active guidelines require that a further conservative multiplier of 70% be applied to account for observed real-world variations in forest growth and permanence.

Third-party verification

In the pursuit of accurate and trusted carbon accounting, third-party verification plays a pivotal role. It serves as an additional layer of scrutiny to ensure that entities adhere to the guidelines faithfully and provides for a higher level of transparency.

To qualify for inclusion within the emissions boundary for Climate Active certification, third-party verification is mandatory in the initial year following plantings. This verification process is undertaken by entities with relevant expertise in vegetation assessments, GIS, and FullCAM. The verification process encompasses several key aspects:

  • Evidence of time of planting: Various forms of evidence can be used to verify the timing of planting, including aerial or satellite images, date-stamped photographs, records of contractors or plant/seed purchases, and estimates of canopy area.
  • Location verification: The boundaries of each planting plot must be precisely defined using field surveys, aerial photographs, date-stamped geo-referenced remotely-sensed imagery, or soil/vegetation/landform maps.
  • Ongoing requirements: Any changes in site characteristics, land management regimes, or instances where plantings fail to achieve forest potential must be addressed. Modified boundaries must be identified in the subsequent technical report submitted to Climate Active.
  • Biomass harvesting: Certain biomass harvesting activities are permitted under specific conditions, such as ecological thinning or the utilisation of fruits, nuts, or seeds.
  • Tree clearing and offset retirement: Deliberate tree cutting necessitates the retirement of offset units equivalent to previously claimed sequestration. Once a tree planting is included in certification, it must remain within the emissions boundary even if certification is terminated and subsequently restarted.
  • Statutory declaration: Each technical report submitted to Climate Active must include a completed statutory declaration, certifying compliance with specific requirements. This includes ensuring no clearing of vegetation outside the modelled area and avoiding double counting of carbon sequestration.

How we can help

The Climate Active guidelines and FullCAM serve as invaluable resources for organisations striving to measure and offset their carbon emissions through tree planting activities. 100% Renewables has proficiency in the use of FullCAM and can use this expertise to help you quantify sequestration from historical tree planting activities or, alternatively, undertake modelling of any potential future tree planting scenarios. Our services can provide you with the numbers you need to determine whether insetting is a viable pathway for you, the likely impact of various scenarios on your carbon footprint, and ways to optimise your planting strategy with regards to species selection and other key factors. Please reach out to Ian for more information.



If you need help developing a net zero strategy, contact us today to learn how we can support your transition. Reach out to  Barbara or Patrick for more information.

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