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Planting a tree sounds like the simplest environmental act there is. Wangari Maathai showed that it can also be a careful answer to a real problem, if you start by listening to the people who have the problem. This post covers her life, why the Green Belt Movement chose trees, and what a science student can learn from how she worked.
Who was Wangari Maathai?
Her Nobel Prize biography says she was born in Nyeri, Kenya, in 1940 and was the first woman in East and Central Africa to earn a doctorate. She studied biological sciences at Mount St. Scholastica College in Kansas (1964), took a Master of Science at the University of Pittsburgh (1966), and earned a PhD in 1971 from the University of Nairobi, where she taught veterinary anatomy. She became chair of the Department of Veterinary Anatomy in 1976 and an associate professor in 1977, the first woman in the region to hold either post.
She was a trained biologist, in other words, before she was an activist. She died on 25 September 2011.
How did the Green Belt Movement start?
In her Nobel lecture, Maathai explained that when the movement began in 1977, she was "partly responding to needs identified by rural women, namely lack of firewood, clean drinking water, balanced diets, shelter and income." She had grown up watching forests cleared and replaced by commercial plantations, which, she said, destroyed local biodiversity and the forests' capacity to conserve water.
The biography adds that she introduced the idea of planting trees with the people in 1976, while serving in the National Council of Women of Kenya. The Green Belt Movement still describes itself as founded in 1977 under that council.
Why trees, and not something else?
Maathai's reasoning, from the lecture, was practical. Tree planting, she said, was "simple, attainable" and gave visible results fairly quickly, which kept people interested. The trees supplied fuel, food, shelter and income, and the work "improves soils and watersheds."
Each of those links is biology you study:
Soil. Roots hold soil in place; a review of root traits that protect slopes (Stokes and colleagues, 2009) lists root distribution, length, orientation and diameter as factors in how well plants fix soil.
Water. A watershed is the land that drains into a stream. Maathai linked forest loss to lost water-holding capacity, and tree cover on that land shapes how much rain soaks in rather than running straight off.
Energy. Firewood is stored chemical energy from photosynthesis. Planting woodlots near homes meant women walked less far to gather fuel.
By the time of her lecture, she said, the movement had planted over 30 million trees.
How did trees become about democracy?
The lecture describes a citizen education programme in which people identify their problems, the causes and possible solutions. That led to questions about who controlled land and forests. Maathai said it "soon became clear that responsible governance of the environment was impossible without democratic space," and trees of peace were planted to demand the release of prisoners of conscience.
The Nobel Committee awarded her the 2004 Peace Prize, according to the prize facts page, "for her contribution to sustainable development, democracy and peace." In the lecture she noted she was the first African woman to receive it. In December 2002 she had been elected to Kenya's parliament and appointed Assistant Minister for Environment, Natural Resources and Wildlife.
What is a common misunderstanding about her work?
"It was just tree planting." The trees were the entry point. The method was getting communities to trace problems back to causes, which is close to how a scientist works.
"Any tree will do." Maathai criticised the replacement of native forest by commercial plantations because it destroyed biodiversity. Which species you plant, and where, matters.
"Science and activism are separate." She brought a biologist's training to a social problem. You can be careful with evidence and still act.
What can a student take from her way of working?
Maathai closed her lecture with a memory of a stream near her childhood home, full of frogs' eggs and tadpoles, which she said had since dried up. She used one small, observed change as evidence of a larger one.
That is a habit you can practise. Pick one place you know well, such as a lake, a park or the trees on your street, and note what lives there and what has changed. Our Class 10 guide to Our Environment covers food chains and ecosystems that will help you explain what you see. For a related story from the Himalayas, read about the Chipko movement and the science of forests.
When an idea such as transpiration or soil erosion is easier to see than to read about, the Fermi Simulation Lab has interactive simulations for ideas that are easier to see than read, which can help you picture the process before you go back to your notes.
This week, write down three environmental problems people near you complain about, and for each one, trace a chain of two causes behind it.
