Virgin Earth Challenge

These were Biochar Solutions, from the US; Biorecro, Sweden; Black Carbon, Denmark; Carbon Engineering, Canada; Climeworks, Switzerland; COAWAY, US; Full Circle Biochar, US; Global Thermostat, US; Kilimanjaro Energy, US; Smartstones – Olivine Foundation, Netherlands, and The Savory Institute, US.

Al Gore had withdrawn from the jury earlier and commented that he was not part of the decision to discontinue the contest.

The Virgin Earth Challenge was intended to inspire inventors to find ways of bringing that back down again to avoid the dangerous levels of global warming and sea level rise predicted by organisations such as the Intergovernmental Panel on Climate Change.

Pyrolysis is a process where biomass is partially combusted in an oxygen-limited environment, which produces a char rich in carbon.

[13] The negative emissions that can be produced by BECCS has been estimated by the Royal Society to be equivalent to a 50 to 150 ppm decrease in global atmospheric carbon dioxide concentrations[14] and according to the International Energy Agency, the BLUE map climate change mitigation scenario calls for more than 2 gigatonnes of negative CO2 emissions per year with BECCS in 2050.

This and other land use change methods is not generally considered among negative emission technologies because of uncertain long-term sequestration permanence.

[4] Another contestant, Carbon Engineering received notification in 2019 that they fulfilled all technical criteria and were selected for the final judgment.

Nevertheless, Carbon Engineering had raised 95 million dollar in investments by other parties, including Bill Gates.

Contestant Graciela Chichilnisky of Global Thermostat, another direct air capture contestant, who had raised 60 million dollars in investments from other parties, expressed strong criticism in Dutch daily Volkskrant: "If you want to encourage scientific progress with a prize, it's not enough to open your mouth and say "25 million dollars."

[25] In 2021, Elon Musk of Tesla Inc announced a $100 million prize for development of the best technology to capture carbon dioxide emissions.