Four demands for a successful long-term strategy for negative emissions 

Publish date: June 5, 2024

For Germany to achieve the goal of climate neutrality by 2045, negative emissions are required. These negative emissions, as depicted globally in the IPCC scenarios [1], remove CO2 from the atmosphere and store it permanently. To create the basis for this, the Federal Ministry of Economics and Climate Protection (BMWK) presented the first key points for the long-term strategy for negative emissions (LNe) in February, assessing the role of negative emissions up to 2060. A stakeholder dialogue, in which Bellona will participate, will also serve as the basis for further development. Bellona welcomes this process and views the paper as a solid foundation for this strategy. However, the following gaps still need to be filled to ultimately create a successful strategy that appropriately assesses Carbon Dioxide Removal (CDR) methods and embeds them in the climate protection portfolio with environmental integrity in mind: 

A robust definition of CDR must be the basis for a negative emission strategy 

Carbon Capture and Storage (CCS), Carbon Capture and Utilisation (CCU) and CDR are often jointly categorised as carbon management. However, the methods must be distinguished from each other and considered separately based on their different effects on carbon cycles and thus different effectiveness as climate change mitigation tools.  

Four principles define collectively Carbon Dioxide Removal [2]: 

1. CO2 is physically removed from the atmosphere. While fossil CCS and CCU prevent CO2 from entering the atmosphere, only atmospheric and biogenic CO2 capture can contribute to a reduction of CO2 in the air and negative emissions.1 

2. The CO2 extracted from the atmosphere is permanently stored. Emitted CO2 remains in the atmosphere for several hundred years to several millennia, permanently impacting our climate. Negative emissions best contribute to climate change mitigation if the extracted CO2 is stored for at least as long.   

3. All emissions in the value chain are taken into account. Upstream and downstream greenhouse gas, including CH4 and N2O, emissions associated with the extraction and permanent storage of CO2, such as emissions from energy consumption, embodied carbon or transport, must also be counted.  

4. More CO2 is extracted from the atmosphere and stored, than GHGs emitted. Ultimately, a CDR process must result in an overall reduction in the amount of GHGs that are in the atmosphere as a result of the activity. 

Several methods and technologies can generate negative emissions. Using the above principles is an easy way to identify methods that can negative emissions and those which cannot, such as CCS applications that capture fossil emissions or methods that do not permanently store the captured CO2.  

We welcome the clear separation and intended assessment of the effectiveness and efficiency of methods and technologies that is based on permanence and reversibility in the LNe cornerstones. However, the paper only refers to storage that is “as permanent as possible”, which we consider to be insufficient. How “long-term extraction and storage” are defined (i.e. permanence) will be clarified during the development of the strategy and thus poses a risk to the effectiveness of the strategy which may face intense political pressure to loosen the rules. 

Separate targets must be set for emission reduction, permanent removal and non-permanent sequestration  

As part of the LNe, the expected residual emissions will be modelled in order to determine a target for negative emissions, from which the scope of the required infrastructure expansion and the level of investment can be derived. It must be made clear here that we cannot remove as much CO2 as we currently expect to remove on the basis of current climate plans [3], and especially not to compensate for all current emissions [4]. Methods for permanent CO2 removal are often based on technologies that, do not yet exist on a large scale, will remain expensive for the foreseeable future, and are very resource-intensive: depending on the method, they require a lot of land, renewable energy, sustainable biomass, or minerals. The availability of CDR will not meet the expected demand to offset the forecast residual emissions in the foreseeable future [3]. As the 2nd “State of CDR” report published yesterday (4th June 2024) indicates [5], the amount removed by the new CDR methods, including BECCS, DACCS or biochar, is currently only around 0.1% (0.002 Gt CO2) of the total 2.2 Gt CO2 removed each year. We argue that negative emissions should not be seen as an arbitrary gap filler between mitigation and zero emissions. Instead, the targets for negative emissions should be based on realistic feasibility assessments, which reflect systemic limitations and opportunity costs such as limited available resources and land use competition. 

To reach climate neutrality, we must reduce residual emissions as much as possible in order to minimise the need for CDR. What constitutes residual emissions will remain a moving target: new technologies will further advance industrial decarbonisation. It is essential to set separate targets for emission reductions and CO2 removals, as indicated in the key points of the LNe. The hierarchy of climate protection measures applies here: the more CO2 we avoid now and do not emit through mitigation measures, the less future generations will have to remove from the atmosphere. When CO2 is captured from the atmosphere, emissions first enter the atmosphere and then have to be removed from there at great expense. For example, the average 2023 carbon credit price for novel CDR ranged between $111-1608 per ton CO2, around 100x more expensive than emission reduction or avoidance credits [5]. If the removals do not take place at the same time, but decades in the future, as envisaged in many climate protection scenarios, climate damage will be incurred in the meantime. This can then only be limited retrospectively, but not completely avoided. What counts as a residual emission should therefore be defined for short time scales, but regularly reviewed in order to further promote innovation. 

Biogenic sinks are exposed to a high risk of reversibility, e.g. due to forest fires or changes in land management [6]. For progress towards a stable net-zero scenario, so-called ‘geological net-zero’, emitted carbon should be returned to permanent storage instead of into biogenic sinks with a less reliable storage. Only in this way can CDR be a long-term and reliable climate solution. Nevertheless, non-permanent sinks often have valuable co-benefits, for example the strengthening of biodiversity, resilience of ecosystems or food security, and can contribute to ecosystem resilience and temporary CO2 sequestration. 

Financial incentives must align with the principles of social credibility, long-term economic and environmental sustainability and the climate benefits of the various CDR approaches

Financial incentives are needed, for CDR methods to close the gap to climate neutrality. The limited resources available to us (e.g. land area, sustainable biomass, renewable energy) must be optimally utilised whilst avoiding exerting further pressure on the already strained Earth system or jeopardising other environmental goals such as biodiversity. At the same time, any subsidies must not incentivise the use of the limited quantities of CDR to offset emissions that could otherwise have been prevented [4].  

While there have been calls to integrate negative emissions into the EU ETS, we believe it is important to exercise extreme caution with regards to a possible interaction between CDR and emissions trading. The ETS is primarily intended to address emission reductions and there is a risk that equating emission reductions with CDR could undermine broader climate mitigation. It will take time to assess appropriate instruments to take into account the different capture and storage characteristics that a portfolio of CDR concepts would entail, and how to deal with different liability time frames. The liability for one tonne of CO2 emitted is clear, easy to understand and is cancelled with the payment of the CO2 price or the use of the certificates. Liability for 1 tonne of CO2 removed is linked to continuous monitoring of stored carbon over centuries to ensure permanence is guaranteed and is therefore substantially more complex. 

How exactly the amount of stored CO2 can be quantified also differs from CDR system to system. In closed systems that store carbon in concentrated form, such as geological formations, it is easier to track carbon fluxes over decades or longer. In open systems such as agricultural soils or the ocean, the amount of carbon removed and added to the storage reservoir can often be initially determined in a relatively accurate way. Over time, however, soils and water move, diluting the removed carbon in these ecosystems or making it impossible to technically distinguish it from naturally occurring carbon [7] and can only be analysed by continuous, intensive and often costly monitoring. 

Incentives that use carbon as a key quantitative metric should rely on accurate carbon accounting to build long-term confidence in their climate benefits. Where this is too difficult, or where there is a substantial risk of environmental trade-offs, focusing on co-benefits instead of carbon removal and aligning incentives other policy goals could be more effective. For example, using such an approach for beneficial and sustainable agriculture could bring direct benefits to farmers (reduced use of synthetic fertilisers, higher crop yields, improved soil pH) [8,9]. It would also help to minimise the administrative burden, e.g. through MRV (Monitoring, Reporting, Verification) requirements, while promoting carbon sequestration activities. For example, flexibility in the implementation of the strategy for the EU Common Agricultural Policy (CAP) in Germany could be utilised for this purpose. 

The strategy must be harmonised with national strategies and European legislation 

Germany is unlikely to be able to achieve its climate goals if it relies solely on CO2removal within its territory and only utilises its own resources. Therefore, achieving net-zero requires careful strategic coordination of national and European policies and processes. Carbon accounting rules must accurately reflect carbon flows and emissions between countries and may need to be adjusted to close gaps [10]. Nevertheless, it must remain clear that the EU’s climate neutrality targets requires this objective to be met within the Union’s borders. 

Planning of CO2 infrastructure, expansion of renewable energy as well as the potential use of sustainable biomass must take into account the need for negative emissions created within Germany and for carbon in transit to storage from other countries. However, this should not limit such resource use for decarbonisation through carbon capture due to potential future negative emissions needs, as this would hamper potential climate action. Geological CO2 storage capacity will not be the main limiting factor for negative emissions availability, although it will be vital to ensure there is sufficient infrastructure for this purpose. Emissions must be reduced as fast as possible using all viable technologies and approaches available.  

The cornerstones of the long-term strategy suggest that Germany could assume an ambitious and leading role in the definition and application of CDR methods. The promising and scientifically sound quality of this strategy, which is probably due to the close involvement of the research projects funded by the BMBF (e.g. CDRterra), must now be maintained in dialogue with the various stakeholders, existing gaps must be closed, and a convincing strategy developed. This could then raise the bar for other countries and bring us closer to our goal of a net-negative society. Bellona looks forward to contributing to the stakeholder dialogue to support robust and timely strategy development, as it must be adopted in this legislative period ending in 2025, to ensure progress. 

Cited literature 

1. Summary for Policymakers. in Global Warming of 1.5°C, 1–24 (Cambridge University Press, 2022).
2. Tanzer, S. E. & Ramírez, A. When are negative emissions negative emissions? Energy Environ Sci 12, 1210–1218 (2019). 
3. Buck, H. J., Carton, W., Lund, J. F. & Markusson, N. Why residual emissions matter right now. Nat. Clim. Chang. 13, 351–358 (2023). 
4. Paul, A. et al. Who Should Use NETPS? Managing Expectations for NETP Demand: Considerations for Allocating Carbon Dioxide Removals. (2023). 
5. Smith, S. M. et al., The State of Carbon Dioxide Removal 2024 – 2nd Edition. (2024) 
6. Rockström, J. et al. We need biosphere stewardship that protects carbon sinks and builds resilience. Proceedings of the National Academy of Sciences 118, (2021). 
7. Rathnayake, D. et al. Quantifying soil organic carbon after biochar application: how to avoid (the risk of) counting CDR twice? Frontiers in Climate 6, (2024). 
8. Bolan, N. et al. Soil acidification and the liming potential of biochar. Environmental Pollution 317, 120632 (2023). 
9. Zhang, M. et al. Chemical Fertilizer Reduction Combined with Biochar Application Ameliorates the Biological Property and Fertilizer Utilization of Pod Pepper. Agronomy 13, 1616 (2023). 
10. Tanzer, S. E., Preston Aragonès, M., Serdoner, A. & Dhakshinamoorthy, A. Global Governance of NETPS – Global Supply Chains and Coherent Accounting. (2022). 

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