Biochar is black carbon produced from biomass [e.g., wood chips, plant residues, manure or other agricultural waste products] through the process of pyrolysis, the thermal decomposition of organic matter in the absence of oxygen.

The specific properties of biochar depend on the feedstock used, as well as the conditions under which it is burned.

One of the main purposes of creating biochar is to transform biomass carbon into a more stable form (carbon storage). Biochar has many applications ranging from soil amendment to environmental remediation, and its long-term benefits toward mitigating climate change are still being explored.