This paper, the second in a series of three, explores the representation of Earth System Science (ESS) in the Australian Curriculum (ACARA, 2018a)) through the Cross Curriculum Priority area of Sustainability and the Australian Curriculum: Science (F-12), with a focus on F-10. Part I (in Teaching Science, 68.1) overviewed the current understandings of the Earth System and the relatively recent interdisciplinary field of Earth System Science (ESS). Here, in Part II, an analysis of the Cross Curriculum Priority area of Sustainability and the Australian Curriculum: Science (F-12) revealed that several key ESS understandings and system-thinking skills were present. How the most current ESS understandings and abilities could lead to a far deeper understanding of the Earth System are then considered and those that may need more attention from students and teachers are highlighted. Part III (in a forthcoming issue) outlines several research-informed pedagogies to help learners develop more scientific understandings of the Earth System, and appropriate related abilities. These Earth System goals and pedagogies needed to be considered in the ACARA review of the Australian Curriculum: Science and the Sustainability Cross Curriculum Priority area -- to that end, this paper was submitted to the appropriate committees. We believe the suggested ESS additions and emphases could comprise one pathway toward a more comprehensive and confident Earth System literacy and a stronger engagement in the Earth and other sciences at every school level, and to the curriculum as a whole. Better-informed, sustainability decision-making and actions by students as today's, and tomorrow's, citizens is the hoped-for outcome. [For Part I, see EJ1346071.]