Baseline Scenario and Additionality Considerations

Baseline Scenario Considerations

It can be assumed that the baseline scenario is the continued quantity of carbon, accounted for as CO₂e, remaining in the fast carbon cycle (ocean, atmosphere, biosphere), in the absence of the project activity. As with the project boundary, all SSRs within the baseline scenario have been identified according to the ISO 14064-2:2019 framework for identifying and selecting greenhouse gas SSRs for regular monitoring or estimating GHG emissions or removals.

, including forest residuals and alkaline waste byproducts, there is no change in baseline input material operations from project activities. In the event residue materials are not utilized, such as with biomass sourced via or alkaline materials sourced from increased carbonate production, emissions associated with direct or indirect production, operations, and sourcing of input materials are included in the .

For marine biomass growth and sinking, given the lack of open ocean macroalgal growth in the absence of project activities, as well as the lack of additional inputs required for macroalgal growth and sinking, the baseline for this activity can be considered zero — though emissions associated with activities enabling this growth, including macroalgae seedstock production and carbon buoy inoculation, are included within project boundaries. In a future state of significant algal biomass growth, secondary effects on phytoplankton carbon uptake associated with competition for nutrients or light may be relevant, though are de minimis for initial deployments. While related to the ocean’s baseline net primary productivity, this potential competition is currently accounted for as a discount factor in the carbon removal quantification approach detailed below.

As such, baseline sources and sinks identified in line with ISO SSR requirements include the following:

• Growth of terrestrial biomass.

• Growth and sinking of marine biomass.

• Bicarbonate storage and ocean mixing.

• Processing of terrestrial biomass (harvest and chipping operations).

• Production of carbonate materials.

Materials used in project activities must be tied to attestations from suppliers as proof of baseline conditions, particularly in regards to the alternative end-state of residue inputs. As an example, as it relates to terrestrial biomass residues, the baseline scenario assumes the contained carbon remains in the fast cycle either through combustion, natural decay, or some form of short-lived industrial processing (e.g., paper, cardboard, pulp), which must then be demonstrated via supplier attestations.

A comprehensive list of ISO-compliant SSRs for both the baseline scenario and activities conducted against the project baseline is detailed in the appendix of this protocol.

Additionality Considerations

In the absence of dedicated carbon finance, either via the voluntary carbon market or alternative carbon procurement programs, there is no current scenario in which project activities would take place, as the project requires significant resources and is unlikely to generate any other material sources of income. As it relates to , an often-used metric when assessing additionality, the current level at which the project activity is conducted is near zero.

For fast-to-slow carbon removal projects, interventions must be additional to the fast-to-slow cycle transfer that naturally occurs within the Earth system carbon cycle — i.e., current state photosynthetic activity leading to durable removal via the biological pump, geologic time scale alkaline rock weathering, or similar natural processes.

For these reasons, deployments following this protocol can be considered additional.