Following on the 2015 Paris Agreement, the Intergovernmental Plan on Climate Change has compiled over 130 modeled scenarios that would meet the Paris goals of keeping global temperature increases “well below 2℃” and preferably below 1.5℃. Overwhelmingly, these models concluded that governments around the world would fail to sufficiently control emissions of global warming pollution and, as a result, have to deploy technologies to suck carbon dioxide (CO2) from the air and keep it from returning.
Based on officials’ statements, the UK government appears to be interested in supporting bioenergy coupled with carbon capture and storage (BECCS) under the guise of helping to spur innovation in CO2 removal. Unfortunately, a large and growing body of peer-reviewed science now tells us that when forest-derived biomass is used for large-scale electricity production, it is a bad idea of multiple fronts. The demand for woody biomass imperils forests around the world. Bioenergy is economically uncompetitive compared to genuine clean energy technologies like solar and wind without massive subsidies, and due to the mature nature of bioenergy technologies, unlikely to experience significant cost reductions in the future. Furthermore, bioenergy is unnecessary. The UK can operate a flexible and low-carbon electricity system year-round as soon as 2021 without converting coal plants to bioenergy.
The subsidies the British government is throwing at companies such as Drax, which totaled £729 million in 2017 or roughly £2 million every day, are a waste of precious public resources intended to support clean energy. UK government support for adding BECCS at scale will require millions more to capture the carbon from biomass plants. For all that, the electricity generated would remain destructive to forests, unnecessary for the reliability of the UK electricity supply, and dirtier than genuinely clean alternatives such as wind and solar that exist today and have been shown to be low-risk both technically and economically.
What’s worse, because most bioenergy use for electricity generation results in increased global warming, adding carbon capture use and storage to these plants, including Drax’s pilot project in North Yorkshire, does not result in net CO2 removal from the atmosphere. Any government program to subsidize BECCS would thus be throwing good money after bad.
NRDC believes that the technology for capturing, and safely storing carbon dioxide (CCS) underground is widely demonstrated and mature, and that the practice is safe if appropriately regulated. However, CCS in conjunction with biomass has been proposed as a means to achieve “negative greenhouse gas emissions.” There is no scientific basis for assuming that BECCS can deliver negative emissions after full emissions accounting for biomass in the power sector. Additionally, there is significant scientific basis to believe that harvesting biomass at a scale envisioned in a number of modeling scenarios would come at an untenable ecological cost.
Even if power plant emissions from burning forest biomass are fully captured and injected into the subsurface, cutting down trees will almost certainly result in a lasting carbon debt for two reasons. First, it is difficult to ensure that the trees will be replanted and kept intact. Second, older trees have been shown to sequester atmospheric carbon at a higher rate, so a permanent carbon debt is created when an older and larger tree is replaced with a younger one: Not only will it take years (likely decades) for the new tree to reach the size of the felled one, but during that time period the now felled tree would have grown even larger if it had been left in place. This “forgone sequestration” from additional biomass harvest in the forest creates a lasting carbon debt.
Beyond the fact that most bioenergy is not carbon negative, large-scale use of BECCS would threaten the environment in a wide range of ways. BECCS demand will very likely be met primarily through crop and tree monocultures (resulting in direct and indirect land-use change) and/or from more intensive or extensive logging of forests. Other more sustainable bioenergy sources are either not available on a large scale (e.g., genuine waste products or new plantations planted specifically to produce biomass) or are not commercially viable with current technology (e.g. algal biofuels). As a result, the sheer amount of land, water, and nutrient needed to produce a sufficient amount of biomass would threaten biodiversity, fresh water supplies and nutrient balances. The amount of land needed to meet the Paris Agreement has been estimated at as much as half the land of the United States.
Throwing public resources set aside for carbon dioxide removal (CDR) research and demonstration towards combining carbon capture and storage with bioenergy, such as at Drax’s facility, is not just wasteful, it actually digs the climate hole deeper. As the saying goes, if you want to get out of the hole, you’d better stop digging. BECCS is the wrong and most risky place to start on CDR.
Supportive policy frameworks that bring forward investment for energy efficiency, true renewables, and smart resources, such as batteries, demand response, and interconnection with Europe must remain the urgent focus of UK climate policy. As for CDR, afforestation and improved agricultural practices are more promising. In addition to pulling CO2 out of the air, these CDR approaches can increase food supplies, improve the resilience of ecosystems, and enhance biodiversity.