The 2nd International Conference on Negative CO₂ Emissions was held at Chalmers University of Technology, Gothenburg, Sweden, June 14-17, 2022. These are Bellona’s main takeaways from the conference.
A deeper understanding of the role and scale of carbon dioxide removal (CDR) is needed to meet climate targets. The fact that CDR is required for our climate goals is clear, but many questions about the deployment of CDR remain unanswered. The conference brought together 275 scientists and experts to engage in various aspects of research relating to carbon removal including various negative emission technologies, climate modelling, climate policies and incentives.
The main topics of the conference included BECCS, DACCS, Biospheric storage, enhanced weathering and ocean alkalinisation.
Bellona’s main takeaways:
Dr. Samantha Eleonor Tanzer, CDR Research and Technology Manager: The increasing pace of CDR research has only been matched by the increasing urgency for action to test CDR options on scales that allow us to assess the system-level uncertainties that prevent us from knowing how much effective CDR is available to us.
Mark Preston Aragonès, Carbon Accounting Policy Manager: It remains abundantly clear that working on CDR does not mean we should relax efforts to reduce emissions. In fact, the more research is produced on CDR, the clearer it becomes that the deployment potentials are likely to be much smaller than anticipated.
Eivind Berstad, Senior Advisor: The scale of carbon we must remove from the atmosphere can be quite daunting. It was therefore of utmost importance that academics, politicians, NGOs and private companies could meet, discuss and learn about how we can do it right.
European Commission with enforced carbon removal message
Bellona registered stronger wording on carbon removal messaging. In the opening keynote of the conference, the European Commission highlighted the need for strict rules for monitoring and verification of carbon removals, with an emphasis on storage permanence. This will be one of the tasks for the expert group on carbon removals, which will support the ongoing work on the Carbon Removal Certification Mechanism. The Commission also called out companies using offsets to claim carbon neutrality:
“Pure offsetting is a bit of a dead end and it’s a bit toxic. I think someone like a big fuel company that says it has climate neutral fossil fuels is not doing any service to what we are trying to do here and we need to be very careful on this”
- Christian Holzleitner, Head of Unit responsible for Land economy and Carbon removals at the European Commission’s Directorate-General for Climate Action.
With regards to geological storage of CO₂, the Commission stressed the importance of deploying open-access CO₂ transport and storage infrastructure across the continent.
Chalmers taking the initiative on carbon removal for the second time
The first and this year’s conference were hosted by Chalmers University. Professor Anders Lyngfelt has been central in both research on the field of carbon removal and organising the conferences. The third conference in the series will be hosted by Oxford University in 2024.
“We will exceed the [carbon] budget in around 2029 and everything thereafter will need to be removed from the atmosphere to meet the 1.5-degree target”
- Anders Lyngfelt, Professor, Chalmers University of Technology
How much carbon removal do we need?
With current policies heading for 2.2 °C – 3.5 °C of global warming by 2100, carbon removals are needed to reach the 1.5 °C target. Modelling by Detlef van Vuuren at Utrecht University shows that between 20Gt and 1000 Gt of CO₂ should be removed by 2100, given an emission peak in 2025, 43% reduction by 2030 and net-zero GHG emissions in 2050. Even the lower range of the estimates is substantial as global CO₂ emissions today are in the range of 30-40 Gt annually.
As an example, if the 490 waste-to-energy plants in Europe were to be equipped with carbon capture and storage, one presenter estimated that this could generate approximately 53 MtCO₂/year of carbon removals. As a result, a common theme during the conference was the need for a portfolio of carbon removal technologies as the optimal way to reduce risk and balance regional deployment.
Another recurring point was the need to bring the grid down to very low carbon intensity so it can generate net carbon removals. For instance, the current electricity grid in Germany is too CO₂ intensive per unit of electricity to generate net negative emissions with DAC installation connected to the grid. However, it was also acknowledged that the electricity demand of CDR, particularly for DAC, was likely to be an ongoing challenge, when paired with overall increasing demand for low-carbon electricity.
What about ‘residual’ emissions?
The concept of “residual” emissions was addressed, namely those emissions sources that would be too difficult to directly abate and therefore would require compensation via CDR in a “net zero” steady state. Emissions from agriculture, aviation, long-distance road and maritime transport, and process and embodied emissions from industry were the most cited candidates to qualify as “hard-to-abate” sectors. However, in the keynote by Wilfred Rickels of the Dr. Kiel Institute for the World Economy, he challenged the idea of ’residual’ emissions, instead arguing that it is our own “high willingness to pay” for specific goods and services, both by allowing them to cost us environmental damage and the price to clean it up, that determines sectors we are unwilling to part with. A few presentations highlighted the concept of consumer demand reduction as a way to manage potentially limited availability of CDR.
From an economic point of view, there are no ‘residual’ emissions. We don’t have to eat meat, we don’t have to fly or drive, we don’t have to build roads, use concrete or air conditioning.
- Wilfred Rickels, Dr. Kiel Institute for the World Economy
Finally, assessment of CDR supply was even more heterogeneous than that of CDR demand, and highly dependent on the scope and detail of the model and its assumption. In one session, Florian Kraxner of IIASA presented a detailed model of afforestation potential, accounting for existing land use and availability, potential forest impermanence, changing climates, and considerations of competing demands, (e.g. water management, agriculture, and biodiversity) estimating a total global afforestation potential of 1-1.6 Gt CO₂/year through 2100. In contrast, in the same session Murray Moinester of Tel Aviv University estimated a 10 Gt CO₂/year sequestration rate for semi-arid forests alone, extrapolated for single experimental reforestation project in Israel.
How much does it cost to remove CO₂ from the atmosphere?
The cost projection of carbon removal is still associated with large uncertainties. Direct air capture is estimated in the range of $100 – $750 per tonne of CO₂, depending on the future gas and power prices, according to a study by Mijndert van der Spek at Heriot-Watt. The study suggested that several pre-requisites must be in place to effectively deploy DAC, including CO₂ transport and storage infrastructure, accounting and verification frameworks, and an effective market.
What are the timelines for the deployment of carbon removal?
As outlined by the IPCC report, CDR can reduce the overshoot of the 1.5 °C target, and hence lower the risk of potential tipping points and irreversible consequences of climate change.
As a result, the need to start building carbon removal facilities soon was highlighted during numerous presentations, even though uncertainties in process conditions remain. By deploying carbon removal processes now, it would be possible to undergo more in-depth research and identify practical barriers to large-scale deployment.
We need to build plants now to get the cost down, then do more R&D to reduce the energy penalty.
- Mijndert van der Spek. Research Center for Carbon Solutions, Heriot-Watt University.
Different CDR options also show different temporal profiles, both for availability of deployment and uptake of CO₂. As illustrated by Barry McMullin of Dublin City University in a case for Ireland, biological sinks, such as afforestation, have the potential to be ramped up more quickly than options that require further development such as BECCS. However, standing biomass and soil carbon are both subject to sink saturation (as well as reversibility) which limits their use as continuous CDR technologies in the long term.
How do we deploy carbon dioxide removal?
Carbon dioxide removal will rely on subsidies in the beginning and will need stability to grow. Several funding mechanisms were explored, including carbon taxes, industry surcharges and mandates on emitters.
The general sentiment was that by the time we approach net-zero emissions, the carbon price, or the marginal abatement cost, itself should theoretically be sufficient to fund all necessary carbon removals to sustain net-zero emissions. However, net-negative emissions would be more complicated.
Several speakers highlighted the need for separate targets for emission reductions and carbon removals, stating that they should not be combined into a net zero-target since carbon removals could potentially divert resources and efforts away from emission reductions. At the same time, it was made clear that carbon must be removed from the atmosphere as soon as possible.
The prospect of having CDR in the future may deter abatement right now and the prospect of not needing it in the future deters CDR deployment right now
- Anne Merfort. Potsdam Institute for Climate Impact Research
What was said about natural solutions for carbon removal?
The theoretical maximum potential for carbon removal in soil was estimated to be 3.7 Gt/year globally. It was highlighted that enhancement of soil organic carbon is finite, reversible and fragile. At the same time, studies suggested it would take between 30 and 50 years until a new equilibrium would be met. A key concern was the need to continuously maintain practices, since reverting to old practices would likely reverse much of the carbon storage:
We know how to do it right, but there is a risk the farmer will revert to old practices.
- Paraphrased from Jean-François Soussana Dr., National Research Institute for Agriculture, Food and Environment.
Peter Holmgren, representing the Swedish forestry industry, claimed an active forestry sector leads to more carbon being stored, and that use of trees can displace fossil emissions. Bellona identified a misleading claim in the presentation as the Swedish forestry industry presented an aggregated number to represent the mitigation effect of carbon stored in forest and “avoided fossil emissions” in the same figure. No further information was provided when asked to provide more clarity on the claim during the Q&A.
Almost none of the scientists were positive about the idea of large-scale monoculture to grow biomass. Large scale deployment of technological solutions for carbon removals were more widely accepted, largely due to their storage permanence.
Agriculture will be a very important sector to reduce methane emissions, a potent short-lived greenhouse gas. Ireland experienced an increase of 19% since 2010 due to increased consumption of milk and meat. A recurring point was that dietary change would not only reduce the need for carbon removals significantly but would also free up more land which could potentially be restored or used to climate mitigation purposes.
We have organic soils leaking carbon like crazy.
- Paul Price Dublin City University
What about the ocean?
A lot of the carbon we have dumped in the atmosphere is absorbed by the oceans, leading to an unprecedented acidification of the oceans compared to the past 65 million years. To counteract the lowering pH-level (i.e. acidification) of the oceans and avoiding ecological disaster, several proposals for ocean alkalinity enhancement were proposed.
The Baltic Sea, the Mediterranean Sea and Great Barrier Reef were proposed as candidates for dispersing large amount of lime, olivine and other minerals to neutralise the carbonic acid. However, the volumes needed are massive. To prevent mass bleaching of Great Barrier Reef, it would likely be necessary to disperse lime at a rate of 250 kg/second. On top of this, the emissions associated with the production and transport of the materials would need to be very low to realise net carbon removals.
What changed in the last four years?
The first international conference on negative CO₂ emissions was held in 2018, and the 2022 edition was delayed for two years from its original 2020 date. In the four years between the two conferences, a stronger consensus was developed about what qualifies as negative emissions: physical removal of greenhouse gases from the atmosphere, long-term carbon storage, and system-level net-negativity. Though, while in 2018 they were mostly called “negative emissions”, in 2022, the term “carbon dioxide removal” has taken the forefront.
While both conferences had a strong focus on assessing individual CDR technologies, rapid progress in the research field led to a noticeable shift in tone: The 2018 conference had many presentations about technology design and potential whereas the 2022 conference had a greater emphasis on system effects and implementation. 2022 also had more panels focused on policy, as well as new panels on national strategies, public support, and financing. This reflects the growing mandate for CDR seen in the IPCC report on 1.5°C and the latest AR6 reports, and the growing momentum in both public and private sector investment into CDR. However, perhaps more sharply aware of the eyes of the world, nearly every presentation in the 2022 conference emphasized the critical point that removals are not a substitute for rapid and immediate reduction.
The Conference served as a wonderful occasion to hear from some of the world’s leading CDR experts on matters relating to ethics, governance, technological developments, modelling and economic analyses. Broadly, the sentiment was that the field of CDR has grown significantly since the previous conference (4 years), but that the underlying research and understanding of CDR has not seen a significant shift. The message to take home from this conference is one most will already be familiar with: sectoral decarbonisation must not be relaxed. Carbon removal will be essential for net-zero goals, and efforts must be pursued today but many questions remain unanswered when it comes to large-scale deployment.