As the European government continues to warn of overshooting 1.5°C warming, attention has shifted toward not only reducing emissions but also actively removing carbon dioxide (CO₂) from the atmosphere. One of the most promising technologies in this realm is Direct Air Capture (DAC) – a process that extracts CO₂ directly from ambient air using chemical or physical methods. Unlike afforestation or soil sequestration, DAC is highly scalable and location-flexible.
How It Works
DAC systems use large fans to push ambient air through a chemical sorbent, typically a solid filter coated with a compound that selectively binds CO₂. Once saturated, the filter is heated or depressurised to release concentrated CO₂, which can then be stored underground (carbon capture and storage, CCS) or reused for industrial processes such as synthetic fuels or building materials.
Two major DAC technologies dominate the field:
- Liquid solvents (e.g., potassium hydroxide solutions): used by companies like Carbon Engineering.
- Solid sorbents (e.g., amine-based resins): used by Climeworks and Global Thermostat.
Environmental and Technical Considerations
DAC is energy-intensive. Extracting 1 tonne of CO₂ requires between 1,500 and 2,500 kWh of heat and electricity. If powered by fossil fuels, DAC risks becoming counterproductive. Therefore, integration with renewable energy is non-negotiable for its climate benefit.
Land and water use are comparatively low, especially when contrasted with bioenergy with carbon capture and storage (BECCS). However, material demand and lifecycle emissions of sorbents still need optimisation.
Deployment Status and Future Outlook
As of 2025, over 20 DAC plants are operational globally, with Climeworks’ Orca and Mammoth plants in Iceland leading the scale-up effort. The U.S. and EU have pledged billions in funding through programs like the U.S. Department of Energy’s Carbon Negative Shot and the EU Innovation Fund.
Still, scaling DAC to meaningful climate impact, removing gigatonnes of CO₂ annually, will require massive investment, policy incentives (e.g. carbon pricing), and transparent lifecycle assessments.
Final Thoughts
DAC is not a magical solution. It cannot replace rapid decarbonization. But in a net-zero strategy, especially to counterbalance hard-to-abate emissions (aviation, cement, agriculture), it may be indispensable.
The key challenge is to deploy it responsibly, powered by renewables, and paired with strong governance.
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