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 such as the UN’s Intergovernmental Panel on Climate Change have recognised that CDR is vital to achieving Paris climate goals. A 2018 report called for immediate action for greenhouse gas removal (GGR) technologies.
The State of Carbon Dioxide Removal for the first time 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 said in a guest post 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.
According to the report, closing the CDR gap requires rapid growth of novel CDR, increasing by a factor of 30 by 2030 on average and by 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) 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.
Researchers have commented to welcome the report and its messages, including Peter Styring, professor of chemical engineering and chemistry at the University of Sheffield, UK.
He said: “This report is an honest evaluation of where we stand and what needs to be done to achieve this. The report clearly identifies that we are lagging behind targets and that more must be done to develop new, game-changing technologies if we are to catch up. Clear life cycle assessment and techno- and social-impact analyses are needed to ensure we invest in technologies that will work. It is clear that many current technologies are not going to achieve this. The authors recognise that there is no silver bullet for CDR. Perhaps we should take a silver buckshot approach.”
Greg Mutch, Royal Academy of Engineering research fellow in the school of engineering at the UK’s Newcastle University, said: “This report is very welcome […] At the same time, the report is a stark warning that we need to do more, and quickly.”
However, CCS expert Jon Gibbins highlighted the report researchers’ failure to acknowledge a key issue of climate change – the duration of CO2 storage. Gibbins is a professor of CCS at the University of Sheffield, UK and director of the UK CCS Research Centre. “In general, this report classifies permanent CDR methods as ‘novel’, which is missing their salient feature,” he said.
“Fortunately for the world, the US government programmes on direct air capture and other technologies with permanent storage, which are mentioned in this report, are an opportunity to provide the transformative examples that the almost exclusively nature-based offsetting approaches in Europe have failed to support.”
Despite the heralded criticality of novel CDR technologies, they face some opposition.
In a recent report from think tank Green Alliance, released just after The State of Carbon Dioxide Removal report, environmentalists argued for nature-based CDR solutions in place of engineered greenhouse gas removal technologies, that would cost UK taxpayers an additional £100bn (US$120.6bn) by 2050.
While it acknowledges that DACCS could lead to “genuine atmospheric carbon removal” it also notes the technology needs high electricity input, making it twice as expensive as BECCS currently. BECCS, it says, could sacrifice carbon-rich habitats and hamper environmental restoration in favour of dedicating land to biomass, possibly resulting in net emissions by 2050.
Green Alliance says that funding farmers to manage land for nature and the climate would cost 1.6 times less overall, as well as “make most of them better off”.
Lydia Collas, policy analyst at Green Alliance, said: “The UK can be genuinely world leading in restoring nature and supporting net zero farming. But we need a plan to make a success of how we use land to restore nature, cut carbon, and grow food. Our report shows that the government has a choice to make. It can support farmers to store carbon and reverse the decline in nature by creating lots of new natural habitats, or it can throw billions at bioenergy.”
As these CDR reports were being released, headlines also featured controversy around carbon offsets, which can counterbalance persisting emissions in hard-to-abate sectors. The Guardian released several reports on the topic, including an article that accused the world’s leading certifier of approving “worthless” offsets.
Verra denied the claims that its projects consistently and substantially over-issue credits.
Independent investigative journalism platform Follow the Money similarly accused the world’s biggest carbon trader, South Pole, of over-issuing offsets. Business Green reports that South Pole refuted that over-issued credits would have a negative climate impact, adding it would close the 27m t gap by slowing the rate it sells credits.
An expert speaking to the Guardian said offsets are actively dangerous, because they remove the incentive to decarbonise and fail to account for the lag between emissions output and the offset impact. Two others acknowledged their benefits but with caveats.
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