Limiting global warming to 1.5°C requires large-scale reductions in greenhouse gas emissions across all sectors, but also the use of carbon dioxide removal (CDR) methods. CDR refers to human activities that capture CO2 from atmosphere and permanently store it in geological, soil or ocean reservoirs, or in products. These methods are divided into durable and non-durable depending on the length of time the removed carbon is stored. Only durable CDR, where carbon is safely stored for millennia, can truly neutralize emissions from the long carbon cycle, such as emissions from fossil fuels.

The necessity of a resilient CDR

Need CDR arises for several reasons: neutralising residual CO2 emissions after reaching net zero, avoiding exceeding the carbon budget, reversing temperature overshooting and neutralising the impact of non-CO2 emissions. Deep emission reductions combined with resilient CDR are essential to limit global warming to 1.5°C. The residual CO2 emissions that remain after implementing all possible mitigation measures must be neutralised by removals stored over millennia. Non-resilient CDR methods such as afforestation, which store carbon for tens to hundreds of years, are not suitable for neutralising emissions from fossil fuels.

Current status and challenges

Despite the urgent need to scale up resilient CDR to achieve global net zero, both capacity and demand remain far below what is needed. In 2023, less than 1.3 million tonnes of CO2 were removed by resilient methods. This would need to increase a thousandfold by 2050 to reach net zero. Current demand for resilient removals is low, with a handful of companies responsible for almost all purchases. Microsoft alone is responsible for more than two-thirds of all contracted resilient CDRsThis limited adoption reflects the lack of clear business incentives for most companies to invest in resilient CDR unless they can use it to support their net-zero claims or for marketing purposes.

Sustainable CDR is not without its challenges. Even when carefully managed, it can lead to significant environmental and social risks, such as competition for land, water and clean energy. In addition, there is risk of double counting of removals, where the same removal is claimed by two or more entities, such as a company and a national government, which undermines the credibility of net zero claims. Transparency in CDR projects is also very limited, as companies and developers often do not disclose key details.

The role of governments and voluntary initiatives

Durable CDR has a limited sustainable potential, making it a scarce resource that cannot serve as a universal solution to ongoing emissions. It should be treated as public good and should be reserved for neutralising residual emissions in hard-to-decarbonise sectors.

Governments are best prepared to develop and scale resilient CDR through measures such as procurement obligations, removal trading schemes or taxation. However, such policies are currently largely absent in most jurisdictions. In this absence, voluntary initiatives such as the Science-Based Targets Initiative (SBTi) and the International Organization for Standardization (ISO) can play a key role in guiding corporate action.

Recommendations for voluntary initiatives

To strengthen support for resilient CDR and ensure its integrity, the following recommendations for voluntary initiatives are key:

1. Require companies to set separate targets for reducing greenhouse gas emissions and for promoting resilient CDR. These goals should not be merged into a single net zero goal at the company level.
2. Ask companies to set monetary targets for resilient CDR in the short and medium term to help finance its scaling.
3. Provide a clear definition of resilient CDR and establish social and environmental safeguards.
4. If voluntary standards continue to require combined objectives, durable CDR should only be used to neutralize residual emissions, which cannot be reduced by current or projected technologies in the coming decades.
5. Long-term and interim targets for a resilient CDR should cover all emission ranges (Scope 1, 2 and 3).
6. A resilient CDR for fossil fuel emissions should ensure that carbon is stored for millennia.
7. A non-resistant CDR is unsuitable to neutralize biogenic methane emissions and CO2 emissions from land use.

These measures are essential to ensure that the promotion of resilient CDR is not just “greenwashing” and that it actually contributes to limiting global warming to 1.5°C. Transparency and independent evaluation of projects are essential to avoid negative impacts on local ecosystems and communities. JRi