Brianna has been a climate activist since she was 11 years old, when she became a founding member of 350 Samoa, and leader of an environmental group called Future Rush. Brianna works extensively with youth in Samoa, a small island state, to raise awareness about climate change and its impacts, and encouraging them to be agents of change. She has addressed world leaders at multiple international conferences, including the Energy Transition Dialogue 2021 in Berlin and COP26 at Glasgow, where she reminded them of their responsibility toward small island states in the Pacific region which face an existential threat from climate change induced flooding, and are leading the global campaign to phasedown fossil fuels for climate change mitigation.