Long-term solutions for carbon removal: Technical advances and nature-based strategies

Balancing carbon removal strategies for a sustainable future

To achieve economy-wide net-zero targets, both nature- and technology-based carbon removal is essential. While significant carbon emission reductions remain the primary strategy, carbon-dioxide removal (CDR) offers a crucial complement, especially for hard-to-abate industries. By capturing and storing CO2 through diverse methods — ranging from afforestation to direct air capture — CDR addresses the urgent need for durable carbon storage. However, each approach has its strengths and weaknesses, requiring a balanced, well-regulated market to maximise their potential and ensure a sustainable transition to net zero.

Carbon removal can be delivered through a wide variety of technologies and processes

Source: AFRY

Current situation and challenges faced

While immediate, significant carbon emission reductions are the primary approaches in the transition to net zero globally, carbon-dioxide removal (CDR) also presents a crucial complementary component of the transition, especially when considering hard-to-abate industries. CDR is concerned with the intentional removal of carbon dioxide from the atmosphere and durably storing it in reservoirs such as growing biomass, soils, or geological formations, and there is a range of nature-based and technical approaches to achieving this.

There are strengths and weaknesses in all technical and nature-based carbon removal. Technical solutions like direct air capture, predominantly offer permanent (millennia timescale) removals but are yet to reach full technical maturity, may be energy-intensive, and require a significant development of the corresponding infrastructure. On the other hand, nature-based approaches such as afforestation and soil carbon sequestration are lower-cost and immediately scalable. However, they offer less durable storage (century timescale) and require careful consideration to avoid a negative impact on food security, biodiversity and sustainability.

The current removals market is predominantly based on the trading of carbon credits registered in voluntary schemes such as Verra, Gold Standard or Climate Action Reserve. Market transparency is limited, and the climate value of certain credits (and thus the financial values) have come under intense scrutiny recently. This has led to an increased focus on the generation of 'high quality' credits, with investors taking steps to go the extra distance in due diligence. Nonetheless, voluntary carbon markets continue to expand the potential for their integration in compliance markets such as the EU ETS.

Removal costs of various carbon dioxide removal technologies (2030)

Among all major carbon dioxide removal (CDR) approaches, reforestation and wood utilisation are low-cost options that can achieve high levels of carbon removal, even at negative costs. In contrast, direct air capture is one of the most cost-intensive technologies for carbon removal.

1: DACCS: Direct Air Capture with Carbon Storage; 2: BECCS: Bioenergy with carbon capture and storage; 3:CNC: Carbon
negative concrete

Note: There is potential for 'non-additional' carbon removals through afforestation/reforestation in cases where existing markets
allow sufficient profits from traditional forestry revenues alone

Source: AFRY

Looking ahead

Effective regulation of carbon markets and international cooperation are essential to significantly reducing and eliminating global carbon emissions. Article 6 of the Paris Agreement aims to establish a UN-sanctioned carbon market, setting global standards for voluntary markets and enabling international collaboration on emission targets. While its principles were confirmed at COP26, many questions about its implementation remain, particularly for the private sector, with negotiations expected to continue through 2026, as discussed at COP28. Additionally, potential risks related to the regulations need to be addressed, including the exploitation of poorer countries and the uncertainty about how selling carbon offsets might impact their ability to meet their own emission reduction targets (NDCs, Nationally Determined Contributions).

Among all the major CDR approaches, there can be sufficient long-term capacity to follow a 1.5°C pathway. The path to achieving this must be carefully navigated. The end game will require residual fossil emissions to be neutralised through permanent removals and technical solutions are rapidly moving toward maturity. Meanwhile scaling nature-based solutions through high quality projects that provide co-benefits beyond just their value as a carbon sink is critical in the short term to shave off peak warming.

Biodiversity, broader ecosystem services, sustainable development, and strong governance are key factors to be enhanced in addition to the emissions impact of high-quality nature-based and technical CDR projects. This ensures not just the reduced risk of greenwashing accusations, but also maximises the multi-functional value of all such projects. There is already evidence of such considerations achieving price premiums in the carbon markets, with players such as Microsoft understanding the additional value at stake.

Continuous improvement of approaches and methodologies across the spectrum of CDR methods is also important. A starting point is often the cultivation of truly sustainable biomass. The carbon can be stored in living forests, or processed to extend the durability of the removal, while also attracting additional revenue streams, e.g. the production of engineered wood construction grade products or the conversion to biochar which can be used as a soil additive. Methodological advances such as dynamic baselining should continue to be implemented to make sure the voluntary (and compliance) crediting meets ever higher standards. Likewise, research and development, and innovative early-stage deployment, can help drive down costs and increase the scalability of all technical solutions. Removals are not a substitute for emission reduction, but without a concerted effort to ramp up the industry, we risk increasing the transition costs to net zero.