Greta wasn't the first to demand climate action. Meet more young activists.

Finkbeiner, 22, a National Geographic Young Explorer, founded a tree-planting nonprofit in his German village in 2007, when he was just nine. Plant-for-the-Planet’s workshops, which teach children about global warming, have created an army of more than 93,000 “climate jus- tice ambassadors” who have become activists in their communities.

Mutunkei, 15, is a member in Kijani Gang, a group of teenage environmental activists in Nairobi, Kenya, who used the Swahili word for “green” as the name of their organisation. So far, he has helped plant more than 600 indigenous trees. Last fall he was invited by Kenyan President Uhuru Kenyatta to help him plant trees at the State House in Nairobi, the presidential residence.

He’ll be old enough this November to vote for the first time in a U.S. presidential election, and he sees registering young people to vote as the best way to spur action on climate change. To do that, the Washington, D.C., resident founded OneMillionOfUs. His organisation combines voter registration with activism on climate change, gun control, immigration reform, and gender and racial equality.

Ali, 11 (shown with her brother, Ali Monis, seven), has sued the Pakistani government, asserting that it has violated her generation’s right to live in a healthy environment by allowing damage from mining and from burning fossil fuels, namely coal. She won a decision affirming that juveniles have a right to sue. Ali’s father, an environmental lawyer, filed the claim on her behalf.

To show support for Greta Thunberg’s school strikes in Stockholm, Villaseñor, then 13, began keeping her own Friday vigils outside the United Nations in New York City, where she lives. From that solitary beginning in December 2018, braving the cold rains, she’s gone on to found Earth Uprising, a climate education group.

On a school assignment in Rwanda, Irakoze, 20, came upon an overflowing landfill in his hometown. He learned that discarded electronics create more than 50 million tonnes of waste globally each year. Now a university student, he founded Wastezon, which uses a mobile phone app to connect consumers with recycling industries. The company has helped send 460 tons of electronics to recyclers in Kigali, Rwanda’s capital.

She has worked in Thailand, Laos, Nepal, and elsewhere on the social impacts of deforestation, landscape restoration, and climate mitigation. Sato, 25, is from suburban Tokyo but now studies in the U.K. “Climate change is not just an issue related to the environment,” she says. “It exacerbates social exclusion, conflict, classism, racism. We all have to take part in climate justice.”