On July 3, 1940, Wangari Muta Maathai was born in the village of Ihithe in the central highlands of Kenya, in a landscape that was still largely forested. By the time she began organizing women to plant trees in the 1970s, much of that forest was gone.

Maathai founded the Green Belt Movement in 1977 as a simple intervention: organize rural Kenyan women, pay them a small stipend for each tree seedling they successfully planted and nurtured. The trees addressed soil erosion, firewood scarcity, and water supply simultaneously. They also gave women something the Kenyan government had not thought to provide — organized collective power.

The government noticed. President Daniel arap Moi's administration labeled her a threat to the state. She was beaten by police. She was arrested. Her then-husband divorced her on the grounds that she was too educated, too strong-willed, and too difficult to control; a judge agreed with him and sentenced her to six months in prison for contempt when she called his ruling biased.

She kept planting. By 2004, the Green Belt Movement had planted more than 30 million trees across Africa. That year, Maathai received the Nobel Peace Prize — the first African woman to do so. The Nobel Committee cited her contribution to sustainable development, democracy, and peace.

She died in 2011. Kenya's deforestation continued.