Defining Carbon Dioxide Removal
Carbon dioxide removal, CO₂ removal or carbon removal refers to the human-driven extraction of the greenhouse gas CO₂ from the atmosphere combined with its permanent storage. The goal of carbon removal procedures is to decrease atmospheric carbon dioxide levels and to mitigate or even reverse man-made global warming. Known carbon dioxide removal techniques include:
- Forestation (planting trees): Trees naturally sequester carbon dioxide to convert into what they are made of – biomass. Learn more about forestation and how it helps to cool the planet.
- Direct air capture and storage: Chemical processes are used to separate CO₂ from ambient air. The separated gas is injected into underground geological formations and prevented from escaping with physical and geochemical trapping (turning the gas into stone).
- Enhanced weathering: Geoengineering approaches that use the dissolution of natural or artificially created minerals to remove CO₂ are referred to as enhanced weathering.
- Blue carbon: Like trees, the world’s ocean ecosystems – mangroves, salt marshes, seagrasses and algae – are sequestering carbon dioxide through plant growth.
- Carbon farming: Agricultural methods aimed at sequestering atmospheric carbon into the soil, crop roots, wood and leaves are catagorised as carbon farming.
- Ocean fertilisation: Here purposeful introduction of nutrients to the upper ocean increase marine food production and remove carbon dioxide.
Direct Air Capture and Storage
Defining Direct Air Capture
The direct air capture, abbreviated as DAC, technology uses chemical processes to separate the CO₂ from the ambient air. This is a still young technology and there is a growing number of companies trying to commercialise it including Climeworks - one of our partners - and Carbon Engineering.
Defining Direct Air Capture and Storage
The separated gas is then injected into underground geological formations, called geological storage, and prevented from escaping with physical and geochemical trapping. The advantage of this process is that a huge amount of CO₂ is removed in a short period of time without needing a lot of space or water however as a very new technology it is currently very expensive.