Carbon negativity is the reduction of an entity’s carbon footprint to less than neutral, so that the entity in question has a net effect of removing carbon dioxide from the atmosphere rather than adding it.
That achievement requires a more aggressive approach than carbon neutrality, which merely nullifies the effect that an entity has on the environment. Carbon-negative status can be achieved by a number of means, including greater carbon sequestration and obtaining carbon offsets from a third party, as well as engaging in activities that directly reduce that amount of carbon dioxide in the atmosphere. Such activities include planting trees, generating green energy and improving energy efficiency.
These latter activities are among those that are naturally carbon negative; others, like those of many industries, require substantial efforts to reduce their carbon footprint to negative values.