BECCS: The saviour of carbon geoengineering?

I recently read this article which tracks the development of Bio-energy with carbon capture and storage (BECCS) from its origins as a proposal within a doctoral thesis by Kenneth Möllersten for Swedish paper mills to benefit financially through capturing its carbon emissions and receiving credits. As mentioned in my previous post, BECCS is currently one of the most exciting and viable CDR technologies and is included in the majority of modelled pathways to achieve ‘the 2°C Scenario’ (2DS).

What is BECCS?

Figure 1: The carbon cycle involved with BECCS. (Source: http://www.bbc.co.uk/news/science-environment-26994746).

The concept of Carbon dioxide capture and storage (CCS) is to separate CO2 released from power plants or industrial sources and transport it by pipeline for storage deep underground in geological reservoirs or saline aquifers (Kheshgi et al., 2012). BECCS is the concept of using CCS at an electric power plant which uses biomass as a fuel and hence produces negative carbon dioxide emissions because the CO2 from the atmosphere is extracted by crops and stored permanently underground (Caldeira et al., 2013).

Due to the smaller size of BECCS plants in comparison to fossil fuel CCS plants, the costs associated with the CCS process are higher (Azar et al., 2006). However, Luckow et al. (2010) suggest that the large-scale utilisation of biomass could enable economies of scale to reduce the additional cost of applying CCS to biomass to only approximately 3% higher than coal.

It is estimated that through sustainably applying BECCS to one-hectare of a typical temperate forest, it is capable of removing approximately 2.5 tonnes of carbon per year (Kraxner et al., 2003). Modelling suggests that BECCS will deliver a significant improvement in the cost of achieving a 450 ppm concentration by 2100 (Azar et al., 2006) and may be necessary for achieving ambitious targets like 350 ppm concentration by 2100 (Azar et al., 2010).


Sounds fantastic, what's the catch?

The main issue with BECCS is the extent to which biomass needs to be commercialised to have a significant contribution towards the previously mentioned emissions targets. The IPCC estimates that to keep CO2 emissions below 450 ppm up to 100 exajoules (EJ) a year of biomass would need to be produced by 2030, with this figure rising to 325 EJ a year by 2100 (Clarke et al., 2014).

To provide some context for the scale of this undertaking, approximately 500 million hectares of land would be required to produce 100 EJ of biomass per year; this is equivalent to one-sixth of the area of global forests, or about 1.5 times the land area of India; in comparison, around 33m hectares of land is currently being used to produce biofuels (WWF, 2014).


With BECCS demanding such a large area of land to act as a feasible method of achieving emissions targets, there are an array of environmental and human concerns that arise. Firstly, a high demand for biofuels is capable of displacing land assigned for food production and hence increasing food prices and decreasing food security (Baier et al., 2009). Environmentally, there are concerns that unsustainable BECCS could increase CO2 emissions if forested areas are cleared to make space for biofuel production.

BECCS has not yet been developed and tested on a commercial scale, and like any other CCS technology, there is always a minor risk of CO2 leakages underground. So, is BECCS the 'saviour' of carbon geoengineering? Perhaps it is a premature saviour. Whilst it certainly has potential to be included alongside other carbon geoengineering methods in achieving emissions targets, there is much work to be done to increase its efficiency to reduce the land area required, as well as the need for a strict global regulatory framework to ensure that the biomass fuelling it is gathered in a sustainable manner.