By
Director of Climate Science & Impact
4 min read
When evaluating climate projects or sourcing carbon credits, two concepts are often discussed together: additionality and permanence.
They are related concepts, and it’s easy to wonder whether they overlap or even describe the same thing. In reality, they answer two very different questions - and the most credible carbon credits from climate projects need both.
At Ecologi, we simplify climate action into three steps guided by our 3Rs framework: Reduce, Restore, and Report. Reducing emissions must always come first in your climate journey. But for the emissions that can’t yet be eliminated, step two - Restore - focuses on contributing to climate and nature projects, including funding high-quality carbon avoidance and removal projects. By focusing on funding high-quality carbon avoidance and removal projects you can offset your ongoing emissions. This is where additionality and permanence become especially important for carbon credit quality.
Additionality vs Permanence
Simply put, additionality is about whether the climate benefit produced goes beyond what is already happening; permanence is about how long the benefit lasts. But let’s dig a little deeper.
What is permanence?
Permanence refers to the long-term durability of the emissions benefits of carbon avoidance or removal projects.
For example, it describes the approximate timescale that carbon stored by carbon dioxide removal projects will remain out of the atmosphere for an extended period, minimising the risk of re-release. It ranges across a spectrum from high-to-low, and a project can have high permanence if it stores carbon for decades or centuries, or longer still.
What is additionality?
Whereas additionality refers to whether the carbon avoidance or removal benefits from a project would have occurred anyway, in the absence of the project.
It evaluates the emissions benefit achieved by the project against a business-as-usual scenario. Therefore, if the project creates a benefit that wouldn’t have happened without the project’s intervention or support, the benefit is additional. In principle, additionality is a yes-or-no assessment.
What’s the difference?
Permanence strategies involve implementing measures to prevent the release of stored carbon back into the atmosphere. This may include selecting long-lived carbon storage options such as those which store carbon in the geosphere, which can lock the carbon away in a stable form for thousands of years.
Additionality strategies focus on demonstrating that the emission avoidance or removals generated by a project are additional to what would have occurred without the project. For example, by demonstrating that the project would be financially non-viable if carbon credits were not being used to finance it.
Why additionality and permanence both matter
The purpose of ensuring permanence is to maintain the integrity of carbon avoidance or removal projects, by minimising the risk of the emissions benefit being reversed. It assures stakeholders that carbon credits generated by the project represent lasting emissions avoidance or removal benefits.
The purpose of assessing additionality is to ensure that finance provided to projects contributes to real and additional emissions avoidance or removal, beyond what would have happened anyway. This is so that buyers are assured that they are meaningfully contributing to the project and its outcomes.
Together, these concepts help distinguish high quality carbon credits that you can be confident in to deliver real, durable climate impact.
How permanence and additionality vary by project type
Project permanence varies by the type of project. Nature-based projects typically have low-to-medium permanence, as carbon is stored in the biosphere and may be re-released on timescales of years to decades through disturbances such as wildfire, disease, or land-use change. Durable or tech-based solutions like direct air carbon capture with storage (DACS) are generally highly permanent because the storage takes place in the geosphere (underground) and carbon can stay there for centuries, if not millennia.
Additionality also varies by project. For example, a renewable energy project may not be additional if economic or legislative incentives already exist for its development. In contrast, forest conservation projects in areas with high deforestation risks can be highly additional, because the forest may be very likely to be cut down or degraded without intervention.
How Ecologi assesses permanence and additionality
To recap, both concepts are crucial for maintaining the integrity of carbon avoidance and removal projects and advancing efforts towards achieving global net-zero. Without additionality, there’s a risk that the projects fund outcomes that would have happened anyway. Without permanence, climate benefits may be temporary and undershoot long-term climate goals.
That’s why Ecologi assesses every project through a rigorous quality lens, with additionality and permanence as core criteria within our Restore pillar. We’ll work with you to reduce your emissions, fund high-quality carbon avoidance & removal projects, and report your progress with confidence.
Want to get started?
Talk to our experts about how we assess carbon projects for additionality and permanence, or explore our carbon project assessment framework in more detail.