Learning progressions are models of how students' understanding of scientific concepts develops over multiple grade levels from novice to expert-like understanding. They are based on research on how students typically learn topics and are designed to guide instruction and assessment to track students' developing understanding over time. This document discusses the motivation for developing a learning progression on environmental literacy, the theoretical framework around scientific practices, and highlights from the progression including its interdisciplinary nature and levels of understanding from notions to generation of new ideas. It also raises questions about how to further develop and validate learning progressions.