January 19, 2023

expert reaction to The State of Carbon Dioxide Removal report

A report on the State of Carbon Dioxide removal has been published by the Oxford Smith School.

This Roundup accompanied an SMC Briefing.

Prof Pierre Friedlingstein, Chair in Mathematical Modelling of Climate Systems at the University of Exeter, said:

“This report gives the first global assessment of Carbon Dioxide Removal (CDR) currently in place worldwide. Massive deployment of CDR is critical to reach net zero emissions and stabilise the climate as quickly as possible. The report highlights that current CDRs, which takes up 2 GtCO2 per year, are primarily due to conventional land management such as reforestation. Novel technologies, such as direct air capture, are still negligible, and will need to scale up by several orders of magnitude to become significant.”

Dr Greg Mutch, Royal Academy of Engineering Research Fellow, School of Engineering, Newcastle University, said:

“This report is very welcome, as carbon dioxide removal (CDR) will be essential to achieve net-zero and international climate change agreements. At the same time, the report is a stark warning that we need to do more, and quickly. If we take the IPCC targets for CDR using BECCS and DACCS (~1000 Gt by 2100) and compare this to the removal rate highlighted in the report (0.002 Gt/yr), we will miss the IPCC target of 2100 by approximately half a million years.

“Whilst this may appear demoralising for those that want to see net-zero etc, this removal rate is for current CDR, not planned CDR. China and the US are surging ahead with technology development, which will soon be followed by deployment. This is due to effective policy and innovation systems, and importantly, large amounts of private capital from companies that are keen to decarbonise their activities. As CDR by its very nature can be done anywhere, if the UK falls too far behind, it may never catch up.”

Prof Jon Gibbins, Professor of CCS at the University of Sheffield and Director of the UK CCS Research Centre, said:

“This report is useful in highlighting the importance of recapturing anthropogenic carbon dioxide from the air but largely ducks the key issue for climate change mitigation, which is how long this carbon dioxide will then be safely stored (see https://www.linkedin.com/pulse/perceptions-permanence-co2-storage-what-long-time-jon-gibbins/). Names are very powerful – calling everything ‘Carbon Dioxide Removal’ completely avoids the issue of how permanent is the subsequent storage.  The same imprecise term, ‘durable’, is used in this report to cover widely different methods, with storage periods ranging from a few decades to millions of years.  In general, this report classifies permanent CDR methods as ‘novel’, which is missing their salient feature.  Fortunately for the world, the US government programs 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.”

Prof Peter Styring, Professor of Chemical Engineering & Chemistry at the University of Sheffield, said:

“Carbon Dioxide Removal is essential if we are to achieve ‘Net Zero’ ambitions. 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 analysis 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. Using the hierarchical approach to waste management, if we don’t allow new fossil-carbon to enter the supply chain, by using a circular economic approach, then we are de facto removing carbon dioxide (the principle of avoidance).”

‘The State of Carbon Dioxide Removal’ by Steve Smith and colleagues was published by the Oxford Smith School at 00.01 UK time on Thursday 19 January 2023.

Declared interests

Prof Pierre Friedlingstein: I have no conflict of interest with this study.

Dr Greg Mutch: “I am funded by the Engineering & Physical Sciences Research Council and Royal Academy of Engineering to develop new, engineered carbon dioxide capture and removal technologies. I have no commercial interests.”

For all other experts, no reply to our request for DOIs was received.