Abstract: In recent years, Earth System Science (ESS) gradually becomes the new trend of the Earth Science. However, Solid Earth Science (SES) has hardly merged with it. This is because ESS is the application of system- or complex-science to the Earth Science, while SES is essentially a category of pure Earth Science, in which linear Earth processes are mainly concerned, or non-linear Earth processes are researched using pure Earth science approaches. Fluid Earth Science (FES), on the other hand, not only encompasses studies of the fluid system of the Earth, but also the strong and weak interactions between fluid and solid systems. Consequently, only FES can mediate the integration of SES into ESS.

Key words: Fluid Earth Science, Solid Earth Science, Earth System Science, complex science, non-linear Earth process