Written by Professor Nilay Shah who convened the Direct Air Capture/Negative Emissions Workshop in London on 18 March 2014
UKCCSRC hosted a workshop on negative emissions technologies in March 2014. A range of presentations covered research into direct air capture, biomass-enhanced CCS, wider greenhouse gas reduction technologies and the UK global calculator project.
An important part of the debate was whether research should be conducted in this area at all, given that CCS is hardly up and running and would be seen by most as more cost-effective and urgent. However it was argued that:
- Most UK energy sytems models (Markal, ETI ESME, CCC) indicate that the UK *needs* some form of negative emissions by around 2040 to meet its emissions targets; if this is the case then research does need to start now because the technologies are not mature yet are assumed in these energy systems models. It’s also good to do fundamental R&D into them; especially because there is no “winning” technology
- There is a lot of cross learning with “conventional” CCS, eg Cranfield work on dry sorbents, the gypsum/ammonia process which was developed for air capture and found to be potentially very good for CCS
- Mitigation via CCS and via negative emissions/air capture should be seen on a spectrum of technologies and not discrete alternatives
- negative emissions technologies will be very useful in decoupling emission sources and sinks
- they can of course be seen as a backstop technology
There were concerns that the perception that such technologies might exist in the future will cause inaction today; this should be countered by indicating that they will always sit on the right hand side of a marginal abatement curve, but could establish an upper bound on large scale decarbonisation costs.
It was felt that a useful outcome from the research community would be an unbiased assessment of different technologies; it seemed at the moment that certain technologies are driven by champions without clear evidence for their performance. Another area for research which was linked to this was the notion of “non-geological” storage which was not production of useful products but some form of stabilised carbon which is removed from the atmosphere (e.g. mineralised, biochar etc.) and a realistic assessment of the scale and costs of this form of storage.
The day ended with a discussion on future research needs which include:
- R&D into how NETs can be deployed in practice and what are the costs and other
- Policy research into how “credits” can accrue for the negative emissions
- How much R&D and technology testing to do? When will the technology be needed at scale and with the appropriate cost reduction
- Science outreach (more climate science but climate science has pessimistic connotations, whereas engineering is more positive…)
- Public acceptance research – is greenhouse gas reduction a hard sell? It is sometimes confused with wider geoengineering activities such as SRM which of course may have undesired consequences
- Developing a technology appraisal platform to quantify costs and other common metrics/impacts
In summary, it was a very interesting day with much more interaction than I expected. Much of the discussion centred around the exact role for NETs and how the fitted into the mitigation landscape. In some cases the discussion broadened out into more general greenhouse gas emission reduction technologies (i.e. beyond those related to CCS such as ocean fertilisation and advanced weathering) and one future action might be to co-host an event on these much broader interventions with a partner such as the IMechE. From the research point of view, it seems the most useful activities would be to continue undertaking work that will de-risk and reduce cost of the CCS-related NETs and for the community to act as a disinterested evaluator of different technologies rather than to champion individual technologies. A new area of “stabilising CO2 without storage” emerged and is also worth further investigation.