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Atmospheric carbon dioxide (CO 2) has affected global surface and atmospheric energy balance since the Industrial Revolution. The spatial distribution of CO 2 concentrations derived from satellite observation are introduced into the coupled Beijing Normal University Earth System Model (BNU-ESM) to study the responses of temperature and surface energy balance to non-uniform CO 2 distribution under the Representative Concentration Pathway 8.5 scenario to 2100. Global annual mean atmospheric CO 2 concentrations are set to equal those specified in the standard uniform CO 2 simulations with differences in spatial pattern and seasonal cycles amounting to tens of ppm. Relative to the uniform CO 2 simulation, global annual mean surface air temperature increases by 0.44 ± 0.03 °C over 2071–2100 when forced with non-uniformly distributed CO 2 , in the Arctic by 1.63 ± 0.28 °C and by 0.67 ± 0.08 °C in northern midlatitudes. The non-uniform CO 2 simulation increases global surface energy by 0.68 ± 0.06 W m−2, principally due to a 0.73 ± 0.08 W m−2 increase in net downward surface longwave flux. Surface energy balance increases by 0.33 ± 0.11 W m−2 (7.4%) averaged over oceans indicting a significant increase in ocean heat uptake. Surface energy budget averaged over the Arctic summer increases by 0.91 ± 0.68 W m−2 in the non-uniform CO 2 simulation, which would have impact on sea ice extent and land ice melt rates with associated feedbacks. The increased surface energy fluxes and temperatures imply reduced time and emission space for greenhouse gases before running into scientific and politically flagged temperature limits. • The distributions of CO 2 concentrations are introduced into Earth System Model. • There are some changes in surface energy fluxes due to non-uniform CO 2. • Changes in surface energy fluxes have impact on sea ice extent with its feedbacks. [ABSTRACT FROM AUTHOR]