7 ways of getting CO2 out of the atmosphere
The world is quickly running out of time to prevent the worst effects of climate change. Even if countries make deep cuts to greenhouse gas emissions, scientists say global temperatures are still on track to rise beyond the 1.5°C limit set in the Paris Agreement. The reason is simple: there is already too much carbon dioxide in the atmosphere.
That means cutting emissions alone will not be enough. We also need to remove carbon that has been building up for more than a century. This effort is called Carbon Dioxide Removal, or CDR. It is now seen as a second pillar of climate action. While reducing pollution slows the problem, CDR focuses on repairing the damage already done.
Around the world, seven major approaches are being developed to remove carbon from the atmosphere. Some rely on natural processes. Others depend on advanced technology. Together, they form a roadmap for how humanity might clean the air and stabilize the planet.
Afforestation and Reforestation
Planting new forests or restoring ones that were previously destroyed is one of the most direct ways to capture carbon. Trees absorb CO₂ as they grow and store it in their trunks, roots, and surrounding soil. These projects also help wildlife and improve water quality. The downside is that they need huge amounts of land, and stored carbon can be lost through wildfires, disease, or logging.
Soil Carbon Sequestration
Farming practices can turn soil into a carbon sink. Methods such as no-till farming, cover crops, and managed grazing help soils store more carbon. These techniques also improve soil health and make farms more resistant to drought. However, the carbon stored is not always permanent and can be released if land use changes.
Biochar
Biochar is a charcoal-like material produced by heating plant or farm waste in the absence of oxygen. When added to soil, it can lock carbon away for centuries. It also makes soil more fertile and able to hold water. The challenge is to produce enough biochar sustainably and build the necessary facilities to do so at scale.
Bioenergy with Carbon Capture and Storage (BECCS)
This approach grows plants for energy, burns them to create power, and captures the carbon before it escapes into the air. The captured carbon is then stored underground. If done carefully, BECCS can provide energy while removing more CO₂ than it emits. However, it requires large areas of land and water, and may compete with food production.
Direct Air Capture with Storage (DACS)
Machines can also pull CO₂ straight from the air. These devices use fans and special filters to trap carbon, which is then compressed and stored deep underground. DACS provides long-lasting storage and does not rely on farmland. The problem is cost: it consumes a lot of energy and remains very expensive. Building enough machines to make a global impact will take time.
Enhanced Weathering
This method accelerates a natural rock formation process. Minerals like basalt can absorb CO₂ as they slowly break down. By grinding these minerals and spreading them over land or ocean surfaces, the reaction happens much faster. The captured carbon turns into stable rock. Enhanced weathering has big potential, but mining and grinding rock on a massive scale takes a lot of energy and could harm the environment.
Ocean-Based CO₂ Removal
The ocean already absorbs a large share of human-made carbon. New methods aim to boost this ability. One option is adding alkaline materials to seawater, which increases the ocean’s capacity to absorb CO₂. Other ideas include growing seaweed or fertilizing waters to encourage algae growth. These could remove huge amounts of carbon, but the risks to marine ecosystems are not fully understood.
No single solution will be enough to tackle climate change. To remove billions of tonnes of carbon by mid-century, the world will need to use many approaches at once. Each method has benefits and risks, but together they offer a chance to repair the atmosphere.
Still, carbon removal cannot replace emission cuts. Every year of delay increases the pressure on these methods and the costs of deploying them. The best path forward is to cut pollution quickly while scaling up carbon removal.
