The regional climate modeling community is actively engaged in the development of regional earth system models (RESMs), applicable in different regional contexts. In a paper published in Atmospheric and Oceanic Science Letters, Prof. Filippo Giorgi from the Abdus Salam International Centre for Theoretical Physics in Italy, and Xuejie Gao from the Institute of Atmospheric Physics, Chinese Academy of Sciences in Beijing, review recent progress in, and future directions for, the field of regional earth system modeling.