Carbon removal takes carbon dioxide out of the atmosphere and stores it. Nature-based and engineered pathways reach that outcome through different systems, with different strengths and risks.
Nature-based removals
Afforestation, agroforestry, soil carbon, wetland restoration and improved land management store carbon in biomass and soils. These activities can operate at large scale and deliver benefits for biodiversity, water, livelihoods and climate resilience.
Their main challenge is reversal risk. Fire, drought, pests and future land-use decisions can release stored carbon. Quantification also needs to separate project effects from natural variability.
Engineered removals
Biochar, direct air capture with geological storage, biomass carbon removal and storage and enhanced weathering use industrial or geochemical processes. Some offer storage measured in centuries or longer and can produce precise operational data.
They are often more expensive, energy-intensive and earlier in their scale-up curve. Feedstock, energy source, transport and storage monitoring determine net impact.
Comparing quality
Durability is one dimension, not the only one. Buyers should also compare additionality, lifecycle emissions, delivery maturity, social safeguards, ecological impact and the confidence interval around quantification.
A lower-cost nature-based unit can be highly valuable when it supports landscape restoration and is backed by strong permanence controls. A durable engineered removal may be appropriate for neutralising residual emissions where long-lived storage is the priority.
Building a portfolio
Many buyers use a portfolio approach: near-term support for high-quality nature-based projects, increasing allocation to durable removals and targeted finance for newer technologies. The right mix depends on the claim, budget, delivery horizon and internal climate strategy.
Sentinel Earth's portfolio includes Dark Earth biochar removal, Seeds of Recovery soil carbon and Cocoa Native Agroforestry.
