Source Title: Published by the University of Michigan Energy Institute
By Derek Martin (MS), Principal Author
Katelyn Johnson (MS) Andrew Stolberg (MS) Xilin Zhang (MS) Carissa De Young (MBA/MS)
This project is adapted from one submitted in partial fullfillment of the requirements for the degree of Master of Science at the University of Michigan School for Environment and Sustainability.
Carbon dioxide removal (CDR) options could be a significant complement to emission reductions to meet the 2°C warming target in the 2015 Paris Agreement, and to ameliorate concerns regarding the viability of nationally determined contributions. CDR is different from other climate mitigation strategies as it aims to increase the rate of negative emissions, rather than reduce net GHG emissions to zero. CDR can be achieved through natural processes, such as photosynthesis, weathering of silicate rock, and absorption by the ocean, or by human-initiated processes, such as chemical bonding and energy generation.
Based on a literature review, CDR or storage potential and estimated costs of ten CDR or CO2 storage options were collected and synthesized, along with a discussion of the benefits, challenges, geographic restrictions, limiting factors, policies, and future research aims.
This analysis suggests that capture of as much as 37 Gt CO2e per year could be feasible at a cost below $70/tonne, before resorting to direct air capture (DAC), which defines the high cost end of the curve in the open literature to date. This capacity is approximately equal to the current level of anthropogenic emissions. Unfortunately, this cost curve relies on significant contributions from aquatic and terrestrial bioenergy with carbon capture and sequestration (BECCS). These are both speculative approaches, with uncertainty about their scalability and impact on the overall global carbon cycle. Nevertheless, the cost curve developed in this analysis is broadly consistent with the small number of previous analyses that have suggested that a suite of likely feasible solutions could remove and sequester 20 Gt CO2e per year at a cost below $100/tonne.
The authors are grateful for the support and guidance of the current and past professors and staff at the University of Michigan Energy Institute, especially Mark Barteau, John DeCicco, Susan Fancy, Daniel Raimi, and Amy Mast. This project would not have been possible without the guidance from the University of Michigan’s School of Environment and Sustainability professor, Rosina Bierbaum. Finally, thank you to all our reviewers– including, but not limited to: Richard Birdsey, Ik Kyo Chung, Annette Cowie, Noah Deich, Riley Duren, Sabine Fuss, Howard Herzog, Mark Hunter, David Keith, Abby Kirchofer, Klaus Lackner, Johannes Lehmann, Greg Rau, Ralph Sims, David Skole, Todd Walter, and Jennifer Wilcox.