Surface scientists are dealing more and more with complex systems that are challenging to investigate from both experimental and theoretical perspectives. The surface science of complex interfaces, such as environmental interfaces under ambient conditions of temperature and relative humidity, requires both advances in experimental and theoretical methods in order for conceptual insights to emerge. In this prospective, several aspects of environmental interfaces and the field of environmental surface science are discussed. These include: (i) adsorbed water on oxide and carbonate interfaces; (ii) surface chemistry of oxide and carbonate interfaces in the presence of co-adsorbed water; (iii) solvation of ions by co-adsorbed water on environmental interfaces; and (iv) research needs and challenges in environmental surface science.