Ways to store carbon (Carbon sequestration)

By Asmita Murumkar, The Ohio State University

Carbon sequestration means capturing carbon dioxide (CO₂) from the air and storing it safely (particularly in plants, soils, oceans, or underground). This helps reduce greenhouse gases such as CO₂, methane, and nitrous oxide that contribute to climate change.

There are both nature-based and technology-based approaches to achieving carbon sequestration.

• Soil Carbon Sequestration: Agricultural practices such as no-till, cover crops, and manure help retain and protect soil carbon. These practices also help improve soil health and crop production.
• Biological Carbon Sequestration: Refers to storing carbon in plant matterby leveraging natural ecosystems such as forests, peatlands, and coastal wetlands. Carbon sequestration occurs when plants use atmospheric CO2 during photosynthesis and store carbon in their biomass.
• Geological Carbon Sequestration: CO2 from the atmosphere or industrial sources (e.g., cement factories) is captured (compressed into a dense fluid) and injected deep into the Earth’s crust for permanent storage.
• Technological (Engineered) Carbon Sequestration: Usesengineering approaches for carbon removal and storage through chemical or mechanical processes. Carbon mineralization achieved through chemical reactions between captured CO2 and mineral-rich material, and biochar produced by pyrolysis of organic materials under low-oxygen conditions, are examples of engineered carbon sequestration.
• Ocean-based Carbon Sequestration: Oceans naturally absorb large amounts of atmospheric CO2. Marine sequestration approaches seek to enhance this process through seaweed/macroalgae cultivation and sinking, or by adjusting ocean alkalinity to increase carbon absorption.
• Urban Carbon Sequestration: Refers to storing carbon through nature-based and engineered solutions integrated into city infrastructure, which includes urban forestry, green roofs/walls, carbon-infused concrete, bioswales, and recycled aggregates.

Role of Agriculture in Carbon Sequestration

Agriculture and agricultural soil play a crucial role in removing and storing carbon. Crops and soil are among the largest potential carbon sinks worldwide. The good news is that producers and landowners can get paid for achieving on-farm carbon sequestration. Some of the easiest ways to achieve carbon sequestration include agroforestry, increasing soil organic matter through reduced tillage, cover crops, organic amendments, and adopting ways to minimize overall energy consumption on farms. Bayer, Indigo Ag, and Truterra carbon programs are examples of private carbon credit programs.

About the author: Dr. Asmita Murumkar is an Extension Field Specialist of Ecosystem Services at the Ohio State University and can be reached at Murumkar.1@osu.edu.