The level of industrial activity is fairly constant, but CO2 circulates quickly into the atmosphere and remains there for a long time. (Its chemical half-life has been estimated at about thirty years.61) Even if major industrialized countries agreed to immediate and substantial reductions in CO2 emissions, it would take years to reduce the growth rate of CO2 in the atmosphere, let alone to actually reverse it. “Neither you nor I will ever see a year in which carbon dioxide concentrations have gone down, not ever,” Schmidt told me. “And not your children either.”
