A Comparative Review of terrestrial and marine carbon dioxide removal (CDR) methods

[Geoengineering News]

https://www.sciencedirect.com/science/article/pii/S2772656825001873

Authors: A. Lieber, C. Morrow, J. Stabile, K. Hornbostel

07 December 2025

https://doi.org/10.1016/j.ccst.2025.100550

Highlights

•CDR methods are categorized by terrestrial vs. marine and biological vs. nonbiological.

•OAE, EW, BECCS and biochar sequestration are well-rounded CDR methods in terms of cost, scale and CO2 storage.

•Biological CDR approaches occupy much more space than nonbiological CDR approaches.

•The costs of moving air and seawater for direct air capture (DAC) and direct ocean capture (DOC) are high.

Abstract

Carbon dioxide removal (CDR) methods that remove CO2 gas from the air and ocean are an essential long-term strategy to complement point source carbon capture. Many CDR methods have been proposed in recent years, and this review organizes and assesses these methods to aid researchers and decision-makers in accelerating development and deployment of CDR. This review organizes CDR methods into four categories: 1) marine/biological, 2) marine/nonbiological, 3) terrestrial/biological, and 4) terrestrial/nonbiological. For each of these categories, the fundamental mechanisms governing CO2 separation are explained, and key CDR methods within each category are discussed. This review also provides a comparison of the four categorical CDR methods based on cost, scalability and carbon storage duration. The infrastructure needs of each CDR category are then covered, and a quantitative study is performed to estimate the costs of moving seawater vs. air to remove CO2. Finally, the operational footprints of various CDR approaches are compared on a 1 Mt/y capture scale. Overall, this review examines the pros and cons of each CDR method to aid decision-makers in selecting the CDR approach that works best within their given constraints.

Source: ScienceDirect