CALCULATIONS OF A CHANGE IN CO₂ CONCENTRATION IN THE ATMOSPHERE FOR SOME STABILIZATION SCENARIOS OF GLOBAL EMISSIONS USING A MODEL OF MINIMAL COMPLEXITY

Yu. A. Izrael and S. M. Semenov

An improved version of the minimal-complexity model allowing calculations of changes in atmospheric CO₂ concentrations under a given scenario of global anthropogenic emission of carbon dioxide is described. The model is applicable for initial pilot calculations, while the detailed global circulation models are to be employed for more precise assessments. The saturation effect is taken into account in computation of the CO₂ flux from the atmosphere to terrestrial reservoirs. Functions for describing changes with time in global emissions connected with fossil fuel burning and cement production as well with changes in land use and land management under no mitigation (new BAU, business-as-usual scenarios) are proposed, and their parameters are estimated using data presented in the literature. Changes in atmospheric concentrations of CO₂ under BAU scenarios and under a set of stabilization scenarios of global emissions are computed. The results could be used in assessing consequences of these changes for the Earth's climate system and life-supporting systems for humans.