Carbon dioxide removal (CDR) will be needed to reach any international net zero emission targets and avoid global warming beyond 1,5°C to 2°C.

Negative emissions technologies (NETs), especially those that go beyond nature-based approaches to provide long-lasting scalable CO2 removals have, therefore, been receiving increased support through government policy and voluntary carbon credit purchases from corporations with ambitious climate goals.

IDTechEx predicts that by 2044, the world’s capacity for such durable, engineered CO2 removals will exceed 630 megatonnes per annum.

In its latest report – Carbon Dioxide Removal (CDR) 2024-2044: Carbon Credit Markets, Technologies, Players, and Forecasts – the research group provides a comprehensive outlook of the emerging CDR industry and carbon credit markets – with an in-depth analysis of the technological, economic, regulatory, and environmental aspects that are shaping this market. In the report, IDTechEx focuses on technologies that actively draw CO₂ from the atmosphere and sequester it into carbon sinks, namely:

* Direct air carbon capture and storage (DACCS), which leverages chemical processes to capture CO₂ directly from the air and sequester it in geologic formations or durable products.

* Biomass with carbon removal and storage (BiCRS), which involves strategies that use biomass to remove CO2 from the atmosphere and store it underground or in long-lived products. It includes approaches such as BECCS (bioenergy with carbon capture and storage), biochar, biomass burial, and bio-oil underground injection.

* Nature-based CDR methods that leverage biological processes to increase carbon stocks in soils, forests, and other terrestrial ecosystems – such as afforestation/reforestation and soil carbon sequestration techniques.

* Mineralisation NETs that enhance natural mineral processes that permanently bind CO₂ from the atmosphere with rocks through enhanced rock weathering, carbonation of mineral wastes, and oxide looping.

* Ocean-based CDR methods that strengthen the ocean carbon pump through ocean alkalinity enhancement, direct ocean capture, artificial upwelling/downwelling, coastal blue carbon, algae cultivation/marine seaweed sinking, and ocean fertilisation.

These CDR technologies are at vastly different stages of readiness. Some are nearly ready for large-scale deployment while others require basic scientific research and further field trials.

Afforestation/reforestation solutions have historically dominated the supply of CDR due to their low cost and high maturity. However, demand for this type of removal carbon credit has been dropping in voluntary markets over the past few years due to several high-profile scandals and the low durability/permanence associated with nature-based CDR.

Instead, corporate buyers have increasingly turned towards highly durable, engineered carbon removal credits generated from approaches such as DACCS and BECCS. These removals offer credible climate action, but have a high price tag and are in short supply. Most durable engineered approaches are yet to be included in compliance markets and, therefore, rely on pre-purchases from corporate buyers for early-stage commercial development.

The new report provides insights into the most promising technologies being developed in CDR, highlighting the pros and cons of each method, examining key drivers and barriers for growth, and comparing the removal potential, capture cost, and durability of all technologies. Despite capacity currently being limited, there has been much interest in DACCS as a solution to permanently remove CO₂ from the atmosphere and reverse climate change. DACCS is immediate, measurable, allows for permanent storage, can be located practically anywhere, is likely to cause minimal ecosystem impacts, and can achieve large-scale removals.

However, the rate at which DACCS can be scaled up is likely a limiting factor. The challenges of deploying DACCS include the large energy inputs (requiring substantial low-carbon energy resources), the high cost, and the sorbent requirements. The industry is aiming for the ambitious target of gigatonne-scale of DACCS removals by 2050. To make this happen, corporate action, investments, policy shapers, and regulatory guidelines need to come together to bring down the costs.

Although BECCS is currently the most mature and widely deployed durable engineered CDR technology, scale-up has historically been slow, and planned capacity is modest. Despite the technologies behind BECCS being relatively mature, there is a risk that using biomass for CO₂ removal and storage may compete with agricultural land and water or negatively impact biodiversity and conservation.

IDTechEx analysis has indicated that BECCS has a large potential to contribute to climate change mitigation, though not at the scale assumed in some models due to economic and environmental risk factors.