Nature's Carbon Machines

Trees, soil, wetlands, and oceans already absorb about half of human CO2 emissions every year. Strengthening these natural sinks is far cheaper than running machines. Restoring forests, planting trees among crops, and rewetting drained peatlands all pull carbon down at a tiny fraction of the cost of mechanical capture — which is why they are the first place most countries look.

Ocean-based approaches are gaining attention. Ocean alkalinity enhancement adds minerals to seawater, raising its carbon absorption capacity so it draws down more CO2 from the air. Coastal projects are also restoring mangroves and seagrass, whose dense underwater soils store carbon for centuries.