A Hacker News discussion explores the feasibility of CO2 sequestration methods, sparked by an article on accelerated limestone weathering using ships. Commenters express skepticism about scalability and energy requirements of various approaches, including planting trees for charcoal, arguing that halting fossil fuel use is paramount. Some propose point-source carbon capture, biomass fuel, and serpentinization as potential solutions, while acknowledging logistical challenges and energy costs. One user detailed theoretical calculations for atmospheric carbon capture using lime burning, estimating significant energy requirements. The discussion touches on the complexities of accounting for carbon emissions throughout the entire process, including mining, transportation, and equipment. Ultimately, the conversation acknowledges the scientific merit of sequestration ideas, but questions their real-world viability and economic practicality in comparison to renewable energy solutions. Several point out that even if technologically feasible, political and economic obstacles may hinder widespread adoption.