This quasi-experimental study examined how the approach of mobile learning and authentic practice (MobiLAP) may foster scientific citizenship among ninth grade students. It was hypothesized that students that form identities as citizen scientists may have more favorable attitudes to contribute to citizen science, have greater interest in science and technology and may be more interested in pursuing education and careers in science, technology, engineering and math (STEM). The treatment group participated in an authentic citizen science project where they studied climate change, spent time in nature and used mobile devices to observe and report phenological data. The control group had a "business as usual" classroom experience studying climate change. The Scientific Citizenship, STEM Interest and Mobile Learning Survey (SCI-ML) instrument was developed to understand students' citizen science identity formation and was administered to both groups pre and post intervention. The instrument was found to be highly reliable for both the entire scale and each of the four subscales. Findings revealed that the MobiLAP approach had a significant impact on participant attitudes toward citizen science identity and careers in STEM areas, but no significant improvement in attitudes toward mobile learning or learning science and technology.