negativeemission

Negative emissions refer to processes or technologies that remove greenhouse gases, especially CO2, from the atmosphere, producing a net negative balance when removals exceed anthropogenic emissions. The term covers both natural and engineered approaches intended to lower atmospheric CO2 concentrations and help meet climate targets.

Natural negative emission methods include afforestation and reforestation, soil carbon sequestration through regenerative agriculture and improved land management, and restoration of wetlands. Biochar and other soil amendments are sometimes included as well. These approaches can offer co-benefits such as biodiversity and improved soil health, but their effectiveness varies with land availability, permanence, and management practices. They may also compete with food production or ecosystems if not carefully planned.

Engineered or technological approaches include direct air capture with storage (DACCS), often paired with geologic storage; bioenergy with carbon capture and storage (BECCS); and mineralization or enhanced weathering processes. These methods typically require substantial energy, specialized infrastructure, and considerable capital. They raise questions about long-term storage security, lifecycle emissions, and the scale needed to impact global temperatures.

Role and outlook: Negative emissions are incorporated in many climate models as a potential component of pathways to limit warming, but they are not a substitute for deep decarbonization. They are generally viewed as complementary tools to reduce residual emissions and achieve net-zero or net-negative targets.

Challenges and criticisms include high costs, energy intensity, permanence and verification of storage, governance and social acceptance, and potential land-use or resource pressures. Deployment is currently concentrated in pilots and small-scale projects, with large-scale implementation still under evaluation.