Ms Namugerwa is a youth climate activist in Uganda. She heard of Greta Thunberg and her Friday strikes in 2018 and was later inspired to take similar action as Greta Thunberg at 13, after she watched a local news report about mudslides and flooding in rural sections of the country. Ms Namugerwa has since become a prominent young climate advocate and an integral member of Africa's most prominent chapter of Fridays for Future taking place in Uganda. She teamed up with Sadrach Nirere, Hilda Flavia Nakabuye, and her cousin Bob Motavu to birth the Fridays for Future Uganda. She has been engaged in Friday striking since February 2019, calling for more climate actions, and she has led the writing of a petition to enforce the ban of plastic bags.
Leah celebrated her 15th birthday by planting 200 trees instead of throwing a birthday party, and since then she has launched the Birthday Trees project, to give out seedlings to those who wish to celebrate their birthdays by planting trees. Her major goal is to see the enforcement of current climate legislation and to attract more coverage of issues of climate change. She organized marches along with other young climate advocates to mark the global climate strike on November 29, 2020. Ms Namugerwa has continuously called on the government of Uganda to fully implement the Paris Climate Agreement. Ms Namugerwa spoke at the World Urban Forum in 2020 and was a youth delegate at COP25.