Abstract: On the basis of theoretical calculations of insolation and Earth remote sensing data on the dynamics of the sea ice area in the Arctic Ocean, a close relationship between long-term changes in the sea ice area and annual insolation contrast in the Northern hemisphere was determined. The change in insolation contrast was generalized (in terms of the source and sink of heat) reflects the change in the meridional insolation gradient that regulates the meridional heat transfer in the ocean - atmosphere system. The regression model was used to make an estimated forecast of changes in the area of sea ice in the Arctic Ocean. According to our estimates, the reduction of the average annual sea ice extent in the Arctic Ocean in 2050 will be 18.3% relative to 2018. The Maximum area (March) will be reduced by 10.1%, and the Minimum area (September) by 60.3%. The decrease in the area of sea ice is associated with an increase in the meridional gradient of insolation and meridional heat transfer resulting from a decrease in the inclination of the Earth's rotation axis in the present epoch.