Dr Alexandre Köberle and Mathilde Fajardy, co-authors of Grantham Institute briefing paper BECCS deployment: a reality check, consider bioenergy with carbon capture and storage (BECCS) technologies, the controversy surrounding them and their role in meeting climate targets.
The rise of BECCS
‘Negative emissions technologies’ gained attention in 2015, when world leaders united behind the landmark Paris Agreement to limit global temperature rise to “well below” 2°C above pre-industrial levels. These ambitious targets can only be achieved through immediate drastic reductions in emissions or, in case of delayed action, by actively removing carbon dioxide from the atmosphere later in the century – using negative emissions technologies.
Bioenergy with carbon capture and storage (BECCS) is one of the most advanced of these technologies. This process involves converting biomass to energy, for example by burning crops or grasses, capturing the carbon dioxide emitted when it is burned, and locking it away deep underground. Most published scenarios consistent with Paris Agreement targets anticipate that BECCS will remove large quantities of carbon dioxide from the atmosphere in the second half of this century. In fact, most scenarios rely on BECCS to remove carbon dioxide at a rate that is about a third of today’s annual emissions. This would potentially restrict temperature rise enough to avoid dangerous levels of climate change. For politicians and world leaders, BECCS came to be seen as a vital safety net; to be used if we don’t manage to reduce greenhouse gas emissions quickly enough.
However, the prevalence of BECCS in scientific scenarios has caused ongoing controversy amongst the research community. Scientists scrutinising BECCS in detail are questioning its ability to deliver any negative emissions at all, let alone at the scale required, and in a sustainable way. Questions they are considering include, what are the dangers of relying on untested technologies at such a large scale? What are potential side effects of ramping up bioenergy production? How much can be produced without compromising societal goals like food security or biodiversity? Does the promise of future ‘negative emissions’ allow governments to delay action to reduce emissions? From being a way to deliver drastic emissions cuts in 2015, BECCS technologies are now being carefully constrained in scenarios, and combined with other solutions such as reducing demand for energy.
Reaching a consensus
The controversy surrounding the role of BECCS in meeting climate targets has highlighted the need for better communication about negative emission technologies to the wider research community, to the political sphere and to industry. In BECCS deployment: a reality check, researchers at Imperial College London lay out the pros and cons of BECCS, investigate limits to its sustainable deployment, and assess the extent to which its different configurations (see figure below) can help meet climate objectives without compromising other societal goals. While writing this paper, we encountered all of the arguments around BECCS. We and our co-authors, along with the four reviewers, all come from different backgrounds and have different takes on the potential of BECCS. This experience was a reminder to us of how current the controversy is, and its scale: if a group of researchers from the same community cannot agree, how will policy-makers across the globe find a way to navigate this issue?
A silver lining…
BECCS alone cannot deliver the scale of negative emissions required without serious challenges to agriculture and the natural environment. Instead, it must be part of a portfolio of technologies that could reduce emissions at a sustainable scale. The discussions around BECCS have sparked interest from researchers and policymakers in other negative emissions technologies, such as direct air capture (sucking carbon dioxide directly from the air) and natural solutions (using land management to increase the carbon uptake of soils). These approaches are now sharing the spotlight with BECCS.
Right now, BECCS can already be of value in increasing the potential of the existing bioenergy industry. Currently, biomass is solely used for energy purposes. With the addition of carbon capture and storage, the bioenergy industry can become a source of both energy provision and carbon dioxide removal. This approach to bioenergy could be of particular value in balancing carbon emissions to net zero carbon in certain sectors, like aviation, where carbon-negative biofuels could be one of the only solutions.
For more on the energy and environmental costs and benefits of different BECCS technologies, and a set of actionable conclusions to move the BECCS discussion forwards, read the briefing: BECCS deployment: a reality check. On 9 April, the Grantham Institute is hosting a panel discussion about BECCS with the authors of the briefing paper and representatives from industry. Find out more
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