资源环境科技发展态势分析平台

Global climate change is a change in the planetary energy (E) balance. It is usually expressed as a change in near-surface air temperature (T_a), but changes in energy content due to T_a (E_T) represent only part of the near-surface energy balance, which also includes E changes due to specific humidity (E_SH). We analyzed MERRA-2 and ERA5 reanalysis data and fifteen CMIP6 Atmospheric Model Intercomparison Project (AMIP) models from 1980-2014. Some 44%, 39%, and 50% of MERRA-2 pixels showed significant increases in E_T, E_SH, and E, respectively. The average increase in E_T (E_SH) was 16.9 (13.6) J kg⁻¹ year⁻¹, but AMIP models estimated larger average E_T (21.6 J kg⁻¹ year⁻¹) and E_SH (16.7 J kg⁻¹ year⁻¹). Global T_a would have increased at nearly double the observed rate if energy was not partitioned into latent heat. Results demonstrate the critical role that specific humidity plays in recent climate changes.