Wangari Maathai died on Sunday.

She won the Nobel Peace Prize back in 2004, the first African woman ever to have such an honor bestowed on her.

She was most famous for launching the Green Belt Movement in Kenya, where she was born.

This movement started with a simple but brilliant idea that she had for empowering women, who had come to her with their concerns about how hard it was to find firewood and clean drinking water.

Her idea: Plant trees.

And over the last three decades, the Green Belt Movement has planted more than 30 million trees.

She understood that this simple act had profound implications.

“Nobody would have bothered me if all I did was encourage women to plant trees,” she told my colleague Amitabh Pal in an interview for The Progressive magazine in 2005. “But I started seeing the linkages between the problems we were dealing with and the root causes.”

One of those root causes was corruption.

Another was sexism.

And another was what she called the privatization of common goods.

For her work, she was repeatedly jailed and beaten, and the Kenyan police once bludgeoned her till she was unconscious, Pal reports.

But she never gave up, and she eventually was elected to the Kenyan parliament by an overwhelming margin before going on to win many international awards.

Here is a short YouTube video about her.

When she accepted her Nobel Prize, she said: “Industry and global institutions must appreciate that ensuring economic justice, equity and ecological integrity are of greater value than profits at any cost. The extreme global inequities and prevailing consumption patterns continue at the expense of the environment and peaceful co-existence. The choice is ours.”

She continued to use her fame for good.

In 2006, she and five other Nobel Peace laureates—Shirin Ebadi, Mairead Maguire, Rigoberta Menchu, Aung San Suu Kyi, and Jody Williams—created the Nobel Women’s Initiative to “magnify the power and visibility of women working in countries around the world for peace, justice and equality.”

Last December, she wrote an op-ed commentary on the climate summit in Cancun, which the Progressive Media Project distributed.

In her article, “Cancun Summit Must Address the Empowerment of Women,” she noted that a U.N. panel on climate financing “did not include a single woman” among its 19 members. “This is unacceptable,” she said.

Women, she argued, need equal participation, basic democratic rights, equal access to education, training, finances, land and other resources if we are to solve the problem of global warming.

“Women are a fundamental part of the climate solution,” she wrote.

Up until the very end, she kept fighting for women’s rights, for peace, for democracy, for economic justice, and for a preserved environment.

The world is a better place because of Wangari Maathai.

If you liked this story by Matthew Rothschild, the editor of The Progressive magazine, check out his story "Obama’s Shameful Stance at the UN."

Follow Matthew Rothschild @mattrothschild on Twitter