October 2004 was an exciting time to be a tree-hugger in Wangari Maathai‘s home country of Kenya. When she was announced as winner of that year’s Nobel Peace Prize, many of my environmentally inclined friends and colleagues were eager to help her figure out what to do with the giant megaphone she had just been handed. Earnest volunteers with ideas and expectations streamed in and out of the downtown Nairobi office hurriedly established to handle the crush of publicity, clutching notes on what they thought the new Nobel laureate should do.

She already knew exactly what she wanted to do: continue planting trees. And so, to the consternation of those who wanted her to launch new campaigns and travel the world nonstop, talking about the global crisis facing indigenous forests, she chose to keep close to home. One dazed friend noted that, in her office, requests from local elementary schools to come plant trees were given equal weight to invitations to speak at Oxford University.

Unlike her fellow African Laureate Desmond Tutu, who used the platform provided by the Nobel to travel the world speaking about the evil of apartheid and other human-rights abuses, Maathai has kept her focus on Kenya. And unlike this year’s winners, Muhammad Yunus and his Grameen Bank, which have made microfinance a cornerstone of international efforts to tackle poverty, Maathai’s Green Belt Movement has found its greatest success in Kenya.

Unbowed, an autobiography by Wangari Maathai.

Read Unbowed, Maathai’s autobiography, and you’ll quickly understand that her focus has always been on her country. She was among the first generation of young professionals who came back after studying overseas to help the country develop following independence in 1963. She recalls her arrival in Nairobi in January 1966 after finishing her studies in the U.S.:

The car radio was playing a recording of one of Jomo Kenyatta’s thundering speeches. I sensed that this was a historic moment: It was not only the first time I had heard his voice, but it was the voice of President Kenyatta. He was urging us to return to the countryside and create wealth from the land by growing coffee and tea and developing our agricultural industry … I almost felt like shouting back at him: “Here I am, Mr. President! I’m back and ready to join in the building of our free country.” I felt a deep sense of pride in being a Kenyan.

After this exhilarating ride from the airport came research and teaching positions at the University of Nairobi. Maathai also became involved in civil-society groups and served for a long time as the chairperson of the National Council of Women. Through her work with such groups, she eventually joined a political movement to challenge President Daniel Arap Moi’s hold on political power. Moi, who succeeded Kenyatta in 1978, became Maathai’s nemesis. Though he had separated from his wife Lena in 1974 (she died three decades later, believing to the end that she would one day be reconciled with him), the president sneered that divorcées such as Maathai had no role in public life. He called her, memorably, “that mad woman.”

Unbowed, a straightforward and unfussy memoir, is most moving when it details the challenges this outspoken, accomplished, passionate woman faced in a Kenya that had no tolerance for anything other than quiet girls, quiet matrons, and quiet grandmothers. The first Kenyan woman to earn a PhD, Maathai’s professional status and personal life suffered from the Victorian-era gender norms of 1970s Kenya. She fought for equal pay and to be taken seriously by her peers. Her marriage crumbled, due in part, she says, to her husband’s inability to handle a strong partner. She endured a humiliating public divorce. She was repeatedly arrested and, in one harrowing sequence in Unbowed, forced to barricade herself inside her house and wait for the police to cut through burglar bars with borrowed army equipment and arrest her.

Kenya has less than 2 percent indigenous forest remaining, and trees are often hacked down to provide wood for charcoal, to clear land for agriculture, or to provide a place for the poor and landless (they are legion) to squat. Maathai’s passion is to heal the scarred Kenyan landscape, which no longer resembles the green highlands she grew up in. Her tree planting first began as a commercial venture (she set up an unsuccessful business to sell trees from a nursery in her backyard) and changed into a nonprofit project. As she recounts in Unbowed, planting trees was, for her, a way to improve the lives of rural women by paying them for planting and tending to trees while tackling the alarming rate of deforestation. With support from Norwegian donors, Maathai became the full-time coordinator of the Green Belt Movement in 1982 and expanded her work.

In the way of all biographies, where a few breezy paragraphs cover years of lived experience, she skims over the tremendous work that must have gone into building an extensive rural enterprise that involved nurseries in remote areas, cash payments for tree cultivation, and verification systems that relied heavily on people who had powerful incentive to confirm that all was going well. She writes, “To my great disappointment, over the years we discovered that many of these young men [hired to keep accurate records of planting and survival rates] turned out to be dishonest.” She insists that such fraud was detected and dealt with. Now, having gotten past these challenges, the Green Belt Movement claims that it has planted more than 30 million trees in Kenya.

The tree planting became overtly political when the Green Belt Movement opposed the grabbing of public land by officials, who would often pass out choice parcels to political cronies or family members (there is often considerable overlap between these two groups). Maathai points out that rewarding individuals with public land actually began with the British colonialists — much of the most productive agricultural land in Kenya changed hands in just this way. Unfortunately, this is one legacy that won’t die. Under the Moi regime, and even today, politicians hive off land held in public trust and give it to private interests. The Green Belt Movement fought this by planting trees on public land scheduled for private development, then using the media to draw attention to their efforts and to the land in peril.

In 1989, Maathai learned of a plan to build a $200 million skyscraper and business complex in the middle of Uhuru Park, one of the few open spaces left in a place once called “The City in the Sun” and now more often called “Nairobbery.” (She eloquently describes the park as “a large swatch of open space amid the bustle of crowds and the concrete and steel of the metropolis.” With equal accuracy, if less eloquence, it could be described as a leafy, idyllic haven for the weary pickpocket.) Maathai began a campaign to draw attention to this encroachment on parkland, pitting herself squarely against Moi; not only did the project have his blessing, it called for a huge statue of the president in the middle of the complex.

Due to Maathai’s passionate appeals to local and international press, and to the concern expressed by the U.N. Environment Program and other donor groups based in Nairobi, the project was eventually stopped. Unbowed suggests that Maathai’s ties to an international network of women’s and environmental groups not only stopped the paving of Uhuru Park; it also possibly protected her life. The regime could arrest and harass her, but it knew that many people in the Western world cared about Maathai’s fate.

Not that her life was untouched by risk and violence. In one memorable episode, Maathai recalls sneaking into Karura Forest in northern Nairobi through a back way, fording through a cold stream, and planting trees on a forest site given over to private developers. The police placed there to protect the land against vicious people armed with tree seedlings let her go that time, but, on a subsequent visit, hired thugs with sticks beat her badly enough to send her to the hospital.

The struggles over Uhuru Park and Karura Forest turned the simple act of tree planting into a political act, part of a pitched battle to save public land from private use. Maathai became even more political when, after a failed run for the presidency in 1997, she became a parliamentarian for her home region of Tetu. In 2003, President Mwai Kibaki, who succeeded Moi, appointed her assistant minister of environment and natural resources. She continues to hold that position, even after winning the Nobel.

Not all Kenyans appreciate the magnitude of the prize. Maathai is considered about as accomplished as Barack Obama, the American senator whose father was Kenyan, even though there are just a handful of Nobel Peace Prize winners in the world. But the Nobel has vindicated her years of struggle against the Moi regime and justified the idealistic, patriotic pride that brought her back to Kenya in 1966 with her American degrees in hand. Reading Unbowed, one gets the sense that no global prize, no matter how prestigious, can match for Maathai the victory of finally being accepted in her homeland for who she is.