In 1999 she was arrested again, this time for protesting the clearing of a forest for a luxury housing development.
But in 2002, things changed for Maathai. Mwai Kibaki and his anti-corruption platform unseated Moi as president and Maathai was elected into the nation's parliament. The following year, she was named assistant minister for the environment. Suddenly her Green Belt Movement had a voice in government.
A New Scrutiny
When Maathai was awarded the Nobel Prize, some critics questioned how environmentalism is relevant to peace. Her selection as the peace prize winner, they said, was inappropriate.
But Maathai believes that the environment and development and peace all are linked.
"The Nobel committee has challenged the world to broaden the understanding of peace," she said in her Dec. 10 Nobel acceptance speech. "This shift is an idea whose time has come."
She has faced a more prickly controversy as well, over comments made about AIDS in an East African newspaper.
Her comments, Maathai says -- that AIDS was created by whites to destroy blacks, and was the product of evil scientists -- were a summation of theories that have gained currency in Africa, and not her own views.
"I neither say nor believe that the virus was developed by white people or white powers in order to destroy the African people," she says on her Web site. "Such views are wicked and destructive."
She does not want her reputation or her status as a Nobel laureate damaged. The prize, she says, isn't hers alone. It belongs to all those women and their trees and the hopes she has helped them nurture.
One wonders, also, if some political aspirations may also be at play. In the old days, when opposition forces were pressing Moi for change, she threw her name in as one of 15 presidential candidates for the 1997 general election. She had not a chance; actually no one had a chance against Moi then.
But today she is a politician. With a Nobel Peace Prize under her belt.
Air America host Rachel Maddow asked Maathai if she wants to be president one day.
Maathai didn't miss a beat. She simply beamed and declared, "Right now, my priority is to be a good Nobel Peace Prize winner."