What is Carbon Removal?

Carbon Capture and Storage (CCS) has a similar objective to CDR, the primary difference is that CDR projects source CO2 from the atmosphere or biomass (short carbon cycle) while CCS projects source CO2 from industrial gas streams, usually from the combustion of fossil fuels (long carbon cycle). When more carbon moves from the long carbon cycle to the short carbon cycle than the opposite, the concentration of CO2 in the atmosphere increases, driving climate change.

 

A common type of CCS project would include capturing the CO2 emitted from a natural gas fired electricity generation plant, concentrating the CO2, and injecting the CO2 underground to recover more fossil fuels – known as enhanced oil recovery. As of 2021, global CCS projects had capacity to capture and store up to 0.04 billion tCO2 annually, of which 80% was used for enhanced oil recovery (EOR)1. It is important to consider that CCS can significantly reduce GHG emissions but, on its own, cannot bring about net negative emissions.

 

The most recent IPCC report highlighted the importance of CDR in stating:

 

“The deployment of CDR to counterbalance hard-to-abate residual emissions is unavoidable if net zero CO2 or GHG emissions are to be achieved”

CDR can be achieved through nature-based methods, like tree planting and ecosystem restoration, and also through engineered methods, which include Direct Air Capture and Storage (DACS), Bioenergy with Carbon Capture and Storage (BECCS), Enhanced Rock Weathering (ERW), and Biochar. While these methods all have the potential to remove carbon dioxide from the atmosphere, none are currently in-use at the scale the IPCC expects is needed. The diagram below identifies the wide range of CDR implementation pathways and the expected duration of carbon stored by the pathway.

 

Removals represent just 5% of emission reductions in the voluntary carbon market3, or about 1.5 million tonnes per year4. It is also important to note that, as of 2021, the vast majority of removal credits come from nature-based solutions, like afforestation and rehabilitation of ecosystems, with less than 10,000 tCO2 removed by new technology5. Existing capacity is far smaller than the expected need. In fact, the IPCC expects that all paths that successfully limit global temperature rise to 2°C require an average technologic CO2 removal of at least 250 million tonnes every year from 2020 to 21006.

 

The growth of CDR depends on implementation strategies that are efficient in both time and cost, and can avoid creating new environmental and social issues. The use of CDR as a tool for managing global GHG emissions remains limited until small-scale projects prove effective. Generating and selling credible carbon offsets provides a tangible path for CDR projects to gain the financing needed for research, growth, and implementation.