The work presents assessment of organic carbon in the soil and СО2 – C emissions for the ten-field crop rotation in a changing climate conditions. The expected weather conditions for the 2021–2050 are estimated with RCP4.5 and RCP8.5 models. The research uses the updated model for the soil carbon cycle RothC-26.3, which describes the dynamics of four active and one inert compartments of the soil organic matter. The numerical studies consider three variants of the ten-fields crops rotation: 1) growing crops without fertilizing; 2) fertilization with mineral fertilizers in N45 P45 K45 and N90P90K 90 doses; 3) fertilization with organic fertilizers in the amounts of 9 and 18 t/ha. The research object is the balance of organic carbon in the soil and СО2 – C emissions from all crop rotation fields and the singular crop rotation field in the climate change conditions.