Pollution issues, anthropogenic climate change, and biodiversity declines, formerly local in scope, accumulate to threaten crossing planetary boundaries and tipping Earth's system to an uninhabitable state. The human-environment identity is an unsung cornerstone of geography that can educate upcoming generations of citizens about trends over time, current conditions, and pathways to a more desirable future. The geography education community should develop and apply human-environment thinking through tools like timelines and big ideas. We hope the geographic thoughts presented herein will provide a scholarly rationale for K-12 educators to consider as they design curricula to share human-environment geography with students.