Between seven and nine billion tonnes of CO2 must be captured from the atmosphere by 2050, according to the second edition of the University of Oxford's report
By 2050, humanity must durably remove four times as much CO2 from the air as today to cap global warming below the crucial target of two degrees Celsius, researchers said Tuesday.
But massively expanding CO2-absorbing forests -– 99 percent of current carbon removal -– could claim land needed to grow food and biofuels, while it remains highly uncertain whether new technologies for sucking CO2 from the atmosphere can be scaled quickly enough, they warned in a major report.