Greta Thunberg, a Swedish environmental activist, was 15 years old when she addressed the United Nations Climate Change Conference in 2018.

Fridays for Future is a youth-led movement that started in 2018 when Greta Thunberg began protesting outside the Swedish parliament every Friday. The movement has since spread to over 150 countries, with young people organizing strikes and protests to demand climate action.

Licypriya Kangujam, an Indian environmental activist, is known for her work on water conservation. She has been advocating for the conservation of rivers and water bodies in India since she was 6 years old.

Melati Wijsen, a young activist from the Philippines, is known for her work against plastic pollution. She co-founded Bye Bye Plastic Bags, a movement that aims to reduce plastic pollution in Bali.

Autumn Peltier, a young activist from Canada, is known for her work on the rights of Indigenous peoples and the protection of water resources. She has been advocating for clean water access and the protection of water bodies since she was 8 years old.

Clean Air Task Force is a youth-led organization that is working to reduce air pollution in cities around the world. The organization was founded in 2013 by a group of young people who were concerned about the health effects of air pollution.

Xiye Bastida, a young activist from the United States, is known for her work on climate justice. She is a member of the Sunrise Movement, a youth-led movement that advocates for a Green New Deal.

Food and Water Watch is a youth-led organization that is working to promote sustainable agriculture and food systems. The organization was founded in 2005 by a group of young people who were concerned about the environmental and social impacts of the industrial food system.

Wangari Maathai, a young activist from Kenya, is known for her work on waste management and recycling. She founded the Green Belt Movement, a non-profit organization that has planted over 51 million trees in Kenya and other African countries.

Animal Legal Defense Fund is a youth-led organization that is working to protect the rights of animals and promote animal welfare. The organization was founded in 1979 by a group of young lawyers who were concerned about the legal status of animals.

Marina Silva, a young activist from Brazil, is known for her work on deforestation and the protection of the Amazon rainforest. She has been a vocal advocate for the rights of Indigenous peoples and the preservation of the rainforest.

Sierra Club is a youth-led organization that is working to promote renewable energy and energy efficiency. The organization was founded in 1892 by a group of young people who were concerned about the environmental impacts of the industrial revolution.

Izzy Cook, a young activist from Australia, is known for her work on climate change and the Great Barrier Reef. She has been a vocal advocate for the protection of the reef and has called on the Australian government to take action on climate change.

Transportation Alternatives is a youth-led organization that is working to promote sustainable transportation and reduce carbon emissions. The organization was founded in 1973 by a group of young people who were concerned about the environmental impacts of the automobile.

Melati Wijsen, a young activist from Indonesia, is known for her work on marine conservation and plastic pollution. She co-founded Bye Bye Plastic Bags, a movement that aims to reduce plastic pollution in Bali.