Carbon dioxide removal (CDR) refers to processes that actively extract CO₂ from the atmosphere and store it long-term. Unlike carbon avoidance offsets, which prevent emissions from occurring in the first place, CDR directly counteracts existing atmospheric CO₂ levels. This makes it a crucial tool for achieving net-zero targets, as it compensates for residual emissions that are difficult to eliminate.

Businesses and policymakers are increasingly shifting their focus from avoidance offsets to high-integrity CDR. While carbon avoidance projects (e.g., renewable energy initiatives) prevent emissions growth, they do not actively remove carbon that has already been emitted. With atmospheric CO₂ levels at record highs, CDR is necessary to reverse historical emissions and restore climate balance.

What defines high-integrity carbon removal?

Not all carbon removal is equal—high-integrity CDR ensures that carbon is genuinely removed, stored for the long term, and accurately accounted for. Key principles include:

Permanence: How long is carbon stored?

Permanence refers to the duration that CO₂ remains removed from the atmosphere. The longer the carbon is stored, the greater its climate benefit. Different methods provide varying levels of permanence:

Geological Storage (e.g., direct air capture with underground injection) can lock carbon away for thousands to millions of years
Mineralisation (e.g., enhanced rock weathering) stores carbon for centuries to millennia
Biochar and Soil Carbon Sequestration can store carbon for decades to centuries
Nature-based Solutions (NbS) (e.g., reforestation, afforestation, and soil restoration) typically sequester carbon for a few decades

What is considered permanent carbon storage?

Different organisations have set minimum thresholds for what qualifies as ‘permanent’ storage:

The Climate Action Reserve (CAR) requires forestry projects to commit to 100-year permanence
The Australian Carbon Credit Unit (ACCU) Scheme mandates permanence periods of either 25 or 100 years
The International Civil Aviation Organisation (ICAO) enforces stricter criteria for CORSIA-compliant credits

What defines high-integrity carbon removal?

Not all carbon removal is equal—high-integrity CDR ensures that carbon is genuinely removed, stored for the long term, accurately accounted for and drives impact on the ground. Key principles include:

Permanence: How long is carbon stored?

Geological storage (e.g., direct air capture with underground storage,) can lock carbon away for thousands to millions of years
Mineralisation (e.g., enhanced rock weathering) stores carbon for centuries to millennia
Biochar (charcoal-like substance made from burning biomass) can store carbon for centuries to thousands of years (possibly even longer as studies continue to prove)
Soil carbon sequestration can store carbon for decades to centuries
Nature-based Solutions (NbS) (e.g., reforestation, afforestation, revegetation and agroforestry) typically sequester carbon for a few decades

What is considered permanent carbon storage?

Different organisations have set minimum thresholds for what qualifies as ‘permanent’ storage:

The ICVCM's Core Carbon Principles (CCP) dictate the CCP stamp refers to 100-year permanence
The Climate Action Reserve (CAR) requires forestry projects to commit to 100-year permanence
The Australian Carbon Credit Unit (ACCU) Scheme mandates permanence periods of either 25 or 100 years
The International Civil Aviation Organisation (ICAO) enforces stricter criteria for CORSIA-compliant credits

Additionality: Would this removal happen anyway?

For a project to be considered high-integrity, it must remove CO₂ beyond what would have happened under business-as-usual conditions. If a project would have gone ahead regardless of carbon finance, it does not provide a genuine climate benefit.

For example, planting trees in an area already protected from deforestation doesn’t count as additional. True additionality ensures that every credit issued represents an actual reduction that would not have otherwise occurred.

Avoiding leakage: Preventing unintended emissions elsewhere

Leakage occurs when carbon removal efforts in one area cause increased emissions elsewhere. A common example is when deforestation prevention in one region leads to increased logging in another. High-integrity projects must implement safeguards to minimise leakage, such as comprehensive land-use planning and jurisdictional approaches to conservation.

Preventing double-counting: Ensuring clear ownership

Double-counting is a major concern in carbon markets, where the same emission reduction or removal is claimed by multiple parties. Without proper accounting, carbon credits lose credibility.

High-quality projects ensure each credit is uniquely identified and tracked, retired after use, and clearly attributed to prevent multiple claims. The corresponding adjustment mechanism under Article 6 of the Paris Agreement helps prevent double-counting by ensuring host countries do not also count sold credits toward their own emissions targets.

Monitoring, Reporting & Verification (MRV): Measuring integrity

Without rigorous verification, it’s impossible to confirm whether a carbon removal project is delivering its intended benefits. High-quality projects undergo third-party verification, life cycle assessments (LCA) to confirm net-negative carbon impact, and independent audits to ensure compliance with established methodologies.

This is particularly important for nature-based projects, where carbon storage is vulnerable to external factors like land-use change and extreme weather.

Additionality: Would this removal happen anyway?

Avoiding leakage: Preventing unintended emissions elsewhere

Carbon leakage occurs when carbon removal efforts in one area cause increased emissions elsewhere. A common example is when deforestation prevention in one region leads to increased logging in another. High-integrity projects must implement safeguards to minimise leakage, such as comprehensive land-use planning and jurisdictional approaches to conservation.

Preventing double-counting: Ensuring clear ownership

Double-counting is a major concern in carbon markets, where the same emission reduction or removal is claimed by multiple parties. Without proper accounting, carbon credits lose credibility.

Monitoring, Reporting & Verification (MRV): Measuring integrity

Without rigorous MRV, it’s impossible to confirm whether a carbon removal project is delivering its intended benefits. High-quality projects undergo third-party verification, life cycle assessments (LCA) to confirm net-negative carbon impact, and independent audits to ensure compliance with established methodologies.

This is particularly important for nature-based projects, where carbon storage is vulnerable to external factors like land-use change and extreme weather.

impact and co benefits of carbon removal

Impact and co-benefits: Driving positive growth on the ground

High-integrity carbon removal also prioritises meaningful environmental and social impacts. Beyond carbon sequestration, projects should contribute to local communities, biodiversity, and ecosystem restoration. Key co-benefits include:

Biodiversity Conservation: Many nature-based solutions, such as reforestation and wetland restoration, enhance habitats for endangered species and improve overall ecosystem health
Water and Soil Health: Sustainable land management practices improve soil fertility, reduce erosion, and enhance water retention, benefiting agricultural productivity and local water systems
Community Livelihoods: Carbon projects should support local and Indigenous communities by providing fair economic opportunities, land tenure security, and sustainable income sources
Resilience to Climate Change: Restoring degraded landscapes and promoting sustainable agriculture can help communities adapt to changing climatic conditions, reducing the risks of droughts, floods, and extreme weather events

By integrating co-benefits into carbon removal strategies, companies can ensure that their investments drive holistic, lasting environmental and social improvements while maintaining carbon integrity.

High-impact and high-integrity carbon removal

Ensuring carbon removal is high-integrity is not just a technical requirement—it’s essential for maintaining trust in climate markets and making real progress in addressing climate change. By prioritising impact and co-benefits, companies promote climate resilience, mitigation and adaptation, whilst meeting their climate / net zero goals.

Companies investing in carbon removal should carefully evaluate projects based on permanence, additionality, verification, safeguards against double-counting and leakage, as well as impact on the ground. Meanwhile, policymakers must continue refining rules to uphold integrity across the market.

At Opna, we help organisations navigate the complexities of carbon removal by connecting them with vetted, high-integrity projects. If you're looking to build a credible, effective carbon removal strategy, get in touch with us today.

Impact and co-benefits: Driving positive growth on the ground

Biodiversity conservation: Many nature-based solutions, such as reforestation and wetland restoration, enhance habitats for endangered species and improve overall ecosystem health
Water and soil health: Sustainable land management practices improve soil fertility, reduce erosion, and enhance water retention, benefiting agricultural productivity and local water systems
Community livelihoods: Carbon projects should support local and Indigenous communities by providing fair economic opportunities, land tenure security, and sustainable income sources
Resilience to climate change: Restoring degraded landscapes and promoting sustainable agriculture can help communities adapt to changing climatic conditions, reducing the risks of droughts, floods, and extreme weather events

By integrating impact and co-benefits into carbon removal strategies, companies can ensure that their investments drive holistic, lasting environmental and social improvements while maintaining carbon integrity.