In the context of a weeklong summer professional development program focused on climate change education, we conducted a qualitative case study investigating how science educators' understandings of learning progressions (LPs) informed their ideas about climate change teaching practice. Participants (N = 27) in the Climate Academy were middle school (n = 14), high school (n = 7), higher education (n = 2), and informal (n = 4) science educators from 2 Mid-Atlantic states in the United States. In cooperation with other Climate Academy facilitators, we engaged participants in a variety of professional learning activities, among which were exploring LPs and their potential utility for informing climate change teaching practice. During these activities with LPs, the science educators engaged with LPs on 2 constructs relevant to climate change: carbon cycling and sea level rise. We collected data in the forms of observational field notes and personal interviews to gain insight into participants' perspectives on LPs and their potential utility for supporting instructional decision making related to climate change. Our analysis of the data indicated that participants related LPs to 4 key areas: advancing student understanding, assessing student understanding, instructional planning, and providing instructional supports. We found that our participants assimilated LP ideas into their preexisting views of teaching and learning, which could facilitate or hinder transformation in their instructional approaches. Implications apply directly to science educator professional development in climate change education and in general to professional development in science education that includes LPs as a focus.