The 2024 State of Carbon Dioxide Removal report co-led by researchers at the University of Oxford suggests that around 7–9bn t/y of CO₂ will need to be removed by 2050 from the atmosphere if the world is to meet the Paris Agreement goal. The authors stress that reducing emissions is the primary way to achieve net zero, but carbon dioxide removal (CDR) has a critical role to play.

Currently just 2bn t/y are being removed by CDR, mostly through conventional nature-based methods like tree planting. Novel CDR methods – like biochar, enhanced rock weathering, direct air carbon capture and storage (DACCS), and bioenergy with carbon capture and storage (BECCS) – contribute 1.3mn t/y, less than 0.1% of the total. Methods which are effectively permanent account for only 0.6mn t/y – less than 0.05% of the total, according to the analysis, which incorporates multiple sustainable development goals and criteria.

To achieve the Paris targets, carbon removal must rise to over 4bn t/y by 2030, with nature-based removals such as ecosystem restoration and agroforestry expected to deliver 97% of this, suggests the study.

The authors call for a diverse range of CDR methods to be rapidly scaled up to address climate change. They warn that while CDR has ‘undergone rapid growth in research, public awareness and start-up companies, there are now signs of a slowdown in development across multiple indicators’.

While investment in CDR research and start-ups is going to an increasing variety of novel methods, few of these methods are currently targeted in government policies and proposals to scale CDR, which accounts for just 1.1% of investment in climate-tech start-ups, they add.

‘Given the world is off track from the decarbonisation required to meet the Paris temperature goal, this shows the need to increase investment in CDR as well as for zero-emission solutions across the board,’ comments Dr Steve Smith of the Smith School of Enterprise and the Environment, University of Oxford.

The report notes that CDR companies have ‘high ambitions’ which, taken together, would drive CDR to levels consistent with meeting the temperature goal of the Paris Agreement. However, the authors say these ambitions have ‘little ground for credibility at present and depend on a much stronger set of policies than currently exists’.

The report urges governments to implement policies that will increase demand for carbon removals. These should include the embedding of CDR policies into countries’ Nationally Determined Contributions (NDCs) and developing better monitoring, reporting and verification systems for CDR. At present, much of the demand for CDR is coming from voluntary commitments by companies to buy carbon removal credits, notes the study.

Governments have pledged, via their NDCs, to increase global carbon removal by 500mn t/y 2030. However, this is only half of the growth in carbon removal needed in the next six years, even in the very best scenarios, which assume dramatic and steep global emission cuts, according to the report.

UK sees CCUS as key to net zero

Meanwhile, the UK government and its independent adviser, the Climate Change Committee (CCC), see carbon capture, use and storage (CCUS) as being ‘essential’ to the nation achieving net zero by 2050. They believe the technology can potentially address several challenges to decarbonising the economy, such as in the power sector, and may be the only practical way to decarbonise some industries, such as cement production.

As a result, four industrial areas, or clusters, are to be established in the UK to capture and store 20–30mn t/y carbon by 2030. In the March 2023 Budget, the Treasury announced up to £20bn to support the early development of the CCUS programme. Two projects will be developed under Track 1 – the HyNet cluster in north-west England and north Wales, and the East Coast Cluster in the Teesside and Humber region. The Acorn project in north-east Scotland and Viking in the Humber will be developed under Track 2.  

According to the UK National Audit Office (NAO), the government ‘does not have and is currently not developing a credible alternative pathway [to net zero] without the use of CCUS’. It continues: ‘In this context, it is critical that DESNZ [Department for Energy Security and Net Zero] succeeds with its CCUS programme if the UK is to achieve its legally binding climate ambitions.’

In its latest report, the NAO says the government ‘has applied the lessons learnt from previous failed attempts to launch CCUS’ but warns that the ‘inherently challenging nature of CCUS remains, given the nascency of aspects of the technology’.  

The NAO suggests that completing negotiations to support the Track 1 cluster projects will be a very significant milestone in signalling the programme’s commercial feasibility and the government’s commitment to CCUS. However, it says that achieving this may require the government to accept that some risks can only be partly mitigated, including higher costs to support early projects, ‘but this could be a risk worth taking if it determines that the potential costs of delays or pursuing alternatives could be significantly higher’.