In the quest to mitigate climate change, scientists have been exploring various methods to capture and sequester carbon dioxide (CO2) from the atmosphere. A recent study, led by Moritz Adam from the Department of Geosciences at the University of Tübingen in Germany, has shed new light on the indirect consequences of these efforts, particularly focusing on land use and energy demands. The study, published in Environmental Research Letters, delves into the Earth system impacts of sun-driven CO2 capture, conversion, and sequestration (sDACCCS).
The research explores the implications of large-scale direct air capture (DAC) combined with the electrochemical conversion of captured CO2 into liquid or solid products. This process, known as sDACCCS, has the potential to retain carbon long-term but comes with significant energy and land use demands. The study utilizes a state-of-the-art Earth system model to simulate these processes and their impacts on the planet.
Adam and his team found that while these process chains can be powered renewably and have minimal direct climate impacts, the land footprint required for CO2 capture and energy harvest is substantial. In a high-efficiency scenario, stabilizing global temperatures to two degrees above pre-industrial levels would demand up to 0.46% of the global land area. This figure jumps to 2.82% when considering present-day technology and pushing the bounds of removal. To put this into perspective, mitigating historical emission burdens within individual countries could require converting an area equivalent to 40% of the European Union’s agricultural land.
“The land use requirements are a significant factor to consider,” says Adam. “While the technology is promising, the environmental burden could be immense if efficiencies remain lower than expected.”
The study highlights the importance of ambitious decarbonization efforts to reduce the risk of land use conflicts. Successful technological development could halve the environmental burden, but the degree to which this could materialize remains uncertain. This research underscores the need for a multifaceted approach to climate mitigation, balancing technological advancements with sustainable land use practices.
For the energy sector, these findings present both challenges and opportunities. The substantial land and energy demands of sDACCCS technologies could drive innovation in renewable energy sources and land management strategies. Companies investing in carbon capture and storage technologies will need to consider these indirect consequences and integrate them into their long-term planning. The study suggests that while sDACCCS has the potential to play a crucial role in climate mitigation, its implementation must be carefully managed to avoid exacerbating land use conflicts and environmental degradation.
The research published in Environmental Research Letters, originally published in German as Umweltforschung: Letters, provides a comprehensive analysis of the Earth system impacts of sDACCCS. It serves as a call to action for policymakers, energy companies, and researchers to collaborate on developing sustainable and efficient carbon capture technologies. As the world continues to grapple with the challenges of climate change, this study offers valuable insights into the complex interplay between technological advancements, land use, and environmental sustainability.
