Uncertainties of predictions of future atmospheric CO2concentrations

摘要: Linear carbon cycle models, tuned to reproduce the CO2 increase observed at Mauna Loa, independently of their individual assumptions, predict almost identical concentration trends for fossil energy scenarios assuming a slightly increasing production in next few decades. The basic information such prognoses therefore is airborne fraction over last 20 years. Uncertainties this quantity are due possible errors estimate fuel consumption and corresponding emission, natural fluctuations baseline level, uncertainties regarding biospheric input uptake as result deforestation reforestation land management. Depending on different assumptions effective fraction, defined ratio alone integrated production, might be low 0.38 or high 0.72, compared apparent 0.55. derived from considering only by ocean, lies range 0.60–0.70. A value 0.40 seems highly improbable. anthropogenic must have been accompanied fertilization effect. Model considerations, however, not contradiction with maximum before 1958, which also would imply preindustrial concentrations 270–280 ppm reported recently.