New research raises concerns that Bioenergy with Carbon Capture and Storage (BECCS) may be more complicated than expected, especially considering its environmental impact
BECCS involves growing biomass crops, like Miscanthus, and capturing the carbon dioxide they release when processed for energy. In a recent study, scientists examined the reliability of BECCS while accounting for the broader environmental impacts of land use.
They specifically assessed how planetary boundaries could constrain the large-scale adoption of BECCS. These boundaries include key factors such as nitrogen flows, freshwater availability, land use changes, and the preservation of biodiversity.
The results showed that if we are to preserve the current balance of Earth’s ecosystems, there may be little room for expanding biomass plantations outside existing agricultural areas.
Six of the nine planetary boundaries are already being exceeded, many of them due to human land use. Converting large land areas into biomass plantations for BECCS would put additional pressure on these already stressed systems. The study found that, when factoring in the constraints posed by these planetary boundaries, the potential for BECCS to contribute significantly to carbon dioxide removal (CDR) is minimal, less than 0.1 gigatons of CO2 equivalent per year by mid-century, under moderate climate scenarios.
Protecting natural ecosystems
The most significant challenges come from the planetary boundary for biosphere integrity.
This boundary shows the need to protect natural ecosystems, including forests and other vital habitats. Converting land for BECCS plantations could further degrade biodiversity, leading to an unsustainable trade-off between mitigating climate change and preserving the planet’s ecosystems. According to the study, biosphere protection alone presents the strongest constraint to BECCS’ potential.
While expanding BECCS plantations could offer a powerful tool in the fight against climate change, the research highlights a fundamental conflict: using land for carbon capture may come at the cost of jeopardising other critical environmental goals. Suppose we are to safeguard our planet’s ecosystems. The study suggests that we must carefully balance climate solutions like BECCS with the imperative to maintain biodiversity and land system integrity.
The study’s authors also point out that the overall capacity of BECCS to contribute to climate mitigation is severely limited when considering the combined impact of all four planetary boundaries: nitrogen, water, land, and biosphere. When these factors are taken together, the result is a near-zero potential for BECCS to make a meaningful dent in global carbon emissions.
This finding shows the importance of a holistic approach to tackling climate change.
Relying heavily on BECCS could lead to unintended consequences, including further stress on fragile ecosystems. As the study suggests, we must prioritise rapid decarbonisation efforts to reduce reliance on methods like BECCS, which may offer limited benefits compared to environmental costs.
Overall, the study shows that if we hope to stabilise the climate without compromising the integrity of our ecosystems, we must embrace a wider sustainability transformation. This includes transitioning to cleaner energy sources, improving land use practices, and investing in other, more sustainable carbon removal technologies that do not strain the Earth’s already overburdened systems.
