Carba

Carba is a Minneapolis-area climate-tech company that turns low-value waste biomass - dead trees, yard waste, and other biogenic scraps - into a stable, charcoal-like material called biocarbon (biochar). Using a patent-pending autothermal pyrolysis reactor and an anoxic (oxygen-starved) burial method, Carba locks carbon away for a certified 1,000+ years, most notably inside existing landfills where the material can also filter pollutants. The company sells the resulting permanent carbon-removal credits - including a five-year, 44,000-tonne deal with Microsoft - and aims to remove a billion tons of CO2 by 2035.