Education per se does not necessarily foster positive environmental behaviors; rather, a complex assemblage of influences including social integration, discovering shared values, strengthening environmental identity, self-efficacy, and agency is needed to foster environmental stewardship. We examine the participant outcomes from a new adult climate education and service course, which is delivered by local organizations. The UC Climate Stewards certification course includes relationship building, social-emotional learning, climate science, climate communication, monitoring resilience, and how to take community-scale action. Based on results from ~154 participants, we observed significant improvement in self-efficacy, with confidence to help protect communities increasing from x¯ = 3.59 (3 is neutral) to x¯ 4.32 (4 is agree) (p < 0.00). The importance of doing something or taking action about climate change appears to be a value that was strongly held prior to taking the course and aligns with motivations for becoming a certified Climate Steward; hence, it only slightly increased from (x¯ = 4.25) to (x¯ = 4.57) (p < 0.00). Climate Stewards’ feeling of competency in talking about the subject increased (from x¯ 3.05 before to x¯ = 4.24 after, p < 0.00, N = 111). Finally, we examine the community-scale stewardship taken by the Climate Steward volunteers, from information provided through self-reporting, and explore additional approaches to researching pathways from education to agency.