Greta Thunberg is a Swedish environmental activist known for her efforts to combat climate change. She began her activism in 2018 by organizing school strikes for climate outside the Swedish parliament, which rapidly grew into a global movement inspiring youth worldwide. Thunberg gained international attention with her speeches at major events such as the 2018 United Nations Climate Change Conference and the 2019 UN Climate Action Summit, where she famously criticized world leaders for their inaction on the climate crisis. Since completing secondary school in 2023, Thunberg has expanded her activism to include human rights and global justice, including support for Ukraine, Palestine, Armenia, and Western Sahara. In 2025, she participated in humanitarian flotillas to Gaza, leading to her detention by Israeli authorities. She remains a prominent figure in environmental and social activism and has received numerous awards, including nominations for the Nobel Peace Prize and being named Time's Person of the Year in 2019.