Forest establishment (bio-sequestration) via bio-diverse (mixed species) plantings or harvested plantations and solid wood products. Only available technology to remove legacy carbon from the atmosphere. Also provides abatement via lower embodied energy building materials, and via combustion of wood waste for bioenergy generation.
Carbon capture and storage (geo-sequestration). All engineering approaches can only achieve abatement (avoidance/reduction of new emissions). None can remove legacy carbon from the atmosphere.
Biomass energy (only renewable technology other than hydro power currently capable of providing base-load power generation).
Solar, wind, wave energy (intermittent power sources in the absence of energy storage capacity). Hydro power (limited opportunity for new developments).