Abstract:
Simulations from Earth System Model show that the rapid increase in atmospheric CO
2 concentration is one of the major reasons for climate change. Satellite data analysis shows that the atmospheric CO
2 concentration is globally nonuniform. There are evident regional discrepancies, mainly caused by anthropogenic carbon emissions. The impact of this spatial difference on global warming has not been thoroughly studied. We evaluated simulation results using the BNU-ESM (Earth System Model of Beijing Normal University) and compared the results with observational datasets. The results show that within a threshold of 2℃ temperature increase between 1901 and 2100, the CO
2 concentration increase forced by nonuniform CO
2 concentration was less than that by uniform CO
2 concentration, which was approximately 4.30 ppm. On the regional scale, the sensitivity of surface temperature to CO
2 concentration in China is lower than that in the United States, Europe, and the Northern Hemisphere. This might result from the combined impacts of CO
2-radiative forcing and climate feedback across these regions; however, this requires future investigation. The impact of nonuniform CO
2 concentration on surface temperature sensitivity could provide scientific support for estimating future carbon sinks under a carbon-neutral target.