A new study, co-authored by a researcher at the Priestley Centre, quantifies the prospects and costs of the ten most important applications of atmospheric carbon dioxide.
Carbon dioxide (CO2), the main greenhouse gas responsible for global warming, can also be used as a raw material, for example in the production of chemicals, building materials, novel fuels, or even as fertilizer in algae farming. CO2 can also be bound to land areas and increase agricultural yields. An overview study, published in Nature, now quantifies the potential in this regard up to the year 2050. It was conducted by research institutions in England, the USA, the Netherlands and Germany.
Using research synthesis methods, the authors assessed the relevant scientific literature on the use of atmospheric CO2, comprising over 11,000 peer-reviewed papers. Based on this information, in combination with the results of an expert survey, utilisation potentials for the year 2050 and break-even prices were calculated. The global potential for the ten most important CO2 utilisation options is quite impressive: in the long term, each option would make it possible to bind at least half a gigatonne of atmospheric CO2 per year. However, the applications are in part mutually limiting – and while CO2 can remain bound in building materials for centuries, storage is limited to only a few weeks in methanol as a fuel.
“The potential uses of atmospheric CO2 need to be systematically analysed”, says Jan Minx, one of the authors of the study and Priestley Chair in Climate Change and Public Policy. “The potential for most industrial applications may be limited, but CO2 utilisation can provide an important boost on the path to greenhouse gas neutrality. For example, it could accelerate the development of removal technologies through new business models and niche markets. This could also cause the total costs for climate mitigation to drop in the long run.”
However, climate change mitigation through reducing emissions remains the number one priority. The study puts a widespread misunderstanding to rest with a solid argument: “If we capture one tonne of CO2 for industrial use at one point, it doesn’t compensate for blowing one tonne into the atmosphere at another point”, emphasises Sabine Fuss, head of the MCC working group Sustainable Resource Management and Global Change and also co-author of the study. “This is because CO2 utilisation goes hand in hand with considerable energy consumption and therefore additional emissions. It’s important to look at lifecycle emissions and substitution effects more closely and distinguish between different options. Our study makes an important contribution in that regard.”
“Greenhouse gas removal is essential to achieve net-zero carbon emissions and stabilise the climate because we haven’t reduced our emissions fast enough,” explains Professor Cameron Hepburn, Director of Oxford’s Smith School of Enterprise and the Environment and lead author of the study. “Even though CO2 utilisation could act as an incentive for carbon removal, we do not advocate subsidies for utilisation. Rather, carbon pricing as a means of targeting emissions would support CO2 utilization in cases in which it is beneficial for the climate.”
The paper, published in Nature is titled ‘The technological and economic prospects for CO2 utilisation and removal’ and is authored by Hepburn, C., Adlen, E., Beddington, J., Carter, E., Fuss, S., Mac Dowell, N., Minx, J., Smith, P., Williams, C.