Novel CO2 removal technologies require massive scale-up push

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Chemical engineer calls for clear life cycle assessments and a “buckshot approach”

NOVEL carbon dioxide removal (CDR) technologies, such as bioenergy with carbon capture and storage (BECCS), need to be scaled up by 1,300 times by 2050, to meet climate goals, says a new report.

It came amidst debate over the merits of technologies used for CDR, as well as of CO2 offsets.

CDR or “negative emissions” technologies capture CO2 from the atmosphere and store it on land, or in oceans, geological formations, or products. Organisations including the UN’s Intergovernmental Panel on Climate Change have recognised that CDR is vital to achieving international climate goals.

The State of Carbon Dioxide Removal report, which has been written by CDR academics from across Europe, estimates the total amount of CDR currently being deployed around the world and compares it to deployment under modelled pathways to meet climate goals, going on to advise how to close the gap.

It estimates current CDR efforts at about 2bn t/y. This is “small” compared to the 36.6bn t/y of CO2 emitted by human activities including burning fossil fuels, researchers involved in the study said in a guest post published on the climate and energy website Carbon Brief. Only 0.1% of this removal is achieved using novel technologies such as BECCS, direct air capture and carbon storage (DACCS), and biochar.

The majority of removal is via “conventional CDR on land” which includes the creation of new forests, restoration of previously deforested areas, and increasing soil carbon.

Pathways that achieve climate targets require an additional 4.8bn t/y of CDR by 2050. For the moment, national pledges are only set to add 1.5–2.3bn t/y over this period, with no plans including novel technologies.

Rapid growth of novel CDR needed

According to the report, closing the CDR gap requires rapid growth of novel CDR, increasing on average by a factor of 30 by 2030 and a factor of 1,300 by 2050. In some scenarios it needs to rise as high as 4,900 times by 2050. Researchers add that conventional CDR also needs to be increased by 1.3 times by 2030 (up to 2.2 times) and doubled by 2050 (up to 3.5 times).

All the explored pathways which limit warming to 1.5°C or 2°C involve substantial CDR between 2020 and 2100, ranging from 450bn t to 1,100bn t CO2.

The researchers encourage urgent and comprehensive policy support towards closing the CDR gap. They say that the CDR required in the second half of the century will only be feasible with significant new deployment in the next 10 years – novel CDR’s formative phase.

However, the team also highlights that CDR is not a “silver bullet”, acknowledging that limiting warming also requires deep cuts to emissions in addition to, not in place of, CDR.

Steve Smith, report author from the school of enterprise and the environment at the University of Oxford, UK, said: “To limit warming to 2°C or lower, we need to accelerate emissions reductions. But the findings of this report are clear: we also need to increase carbon removal, too, by restoring and enhancing ecosystems and rapidly scaling up new CDR methods.

“Many new methods are emerging with potential. Rather than focusing on one or two options we should encourage a portfolio, so that we get to net zero quickly without over-relying on any one method.”

The State of Carbon Dioxide Removal is expected to be the first in a series of reports, through which researchers aim to build a community, bridge data gaps, and support scale up of CDR responsibly and equitably.