Skip to main content
Wanjira Mathai, Vice President and Regional Director for Africa, World Resources Institute, sits on a panel and speaks into a microphone.

“A healthy environment supports healthy people.”

Wanjira Mathai unpacks connections between climate change and public health.
Filed Under
Written by
Leah Samuel
May 15, 2024
Read Time
5 min

Wanjira Mathai was just six years old when her mother, Wangari Maathai, founded the Green Belt Movement, a grassroots effort to fight deforestation through planting trees. Nearly 30 years later, Maathai was awarded the Nobel Peace Prize for that work, and her daughter had become a respected environmentalist and leader in her own right. After earning master’s degrees in public health and business at Emory University, Wanjira Mathai joined the Carter Center, working on disease control, and then returned to Kenya to become the Green Belt Movement’s director of international affairs and, later, its executive director. (She remains on its board of directors). Today, Mathai helps lead the World Resources Institute as its managing director of Africa and global partnerships. She continues to help African countries make environmental restoration decisions that also improve local economies. She spoke with Leah Samuel for Harvard Public Health.

HPH: What is your public health perspective on climate change?

Mathai: At the Carter Center, the diseases I worked on eradicating, like Guinea-worm disease and river blindness, were about polluted water. The water was harboring vectors like mosquitos, breeding in rivers and carrying disease. And with flooding comes infectious diseases like cholera, especially in urban areas. People get infected very quickly. And when people can’t get clean water to drink, health is affected immediately.

Climate change has essentially exacerbated all of that. And land use change, urbanization, and growth has also resulted in a lot more degradation.

Sign up for Harvard Public Health

Exploring what works, what doesn't, and why.

Delivered to your inbox weekly.

  • By clicking “Subscribe,” you agree to receive email communications from Harvard Public Health.
  • This field is for validation purposes and should be left unchanged.

HPH: Regions of Kenya, where your mom started the Greenbelt Movement, were among the earliest places where environmental degradation directly affected public health. What has that looked like over the years?

Mathai: There’s been so much land use change, especially in ecosystems of importance for water. When it rains, the water is supposed to very gently come down the trunks of the trees and soak into the underground aquifers—and release to us as rivers. That’s the classic water cycle.

Now, a lot more land is paved; a lot more land is degraded. Trees have been removed, replaced with crops. That rainwater now is rushing, running off before it ever has a chance to seep into the underground aquifers. That creates flooding and, of course, disease, displacement, and loss of lives and livelihoods.

That’s why it is so important to restore as much as we can. Let’s create buffer zones along rivers. And let’s plant bamboo along those rivers. Bamboo is known as a sponge. It allows water to slow down and go under the ground.

HPH: You’ve said that if we do not address poverty, climate change will be worse. Why is it important to work on both?

Mathai: Poverty is the chief driver of vulnerability. If people are living on the edge of the edge, they are living precariously in such poverty that any small shock will push them over. It’s very difficult for them to adapt and build the sort of resilience that’s needed to survive climate shocks.

Some countries invest a lot in saving lives during climate events like floods. But when the people come back, their livelihoods are gone. Businesses have been washed away. The same communities working to restore their landscapes are also working to secure their food supplies and water supplies.

All of that is a function of a healthier environment as well. We have got to address poverty as part of the resilience-building. We have got to transform people’s lives and livelihoods as part of addressing climate.

HPH: Are governments are vulnerable as well? How does poverty affect them?

Mathai: As climate events are getting worse, many countries cannot adapt amidst abject poverty. The International Panel on Climate Change had a fascinating example in their report. Bangladesh and the Netherlands are not so different in terms of their exposure to climate-related risks like flooding. In fact, the Netherlands is lower in sea level, right? You would think the Netherlands would suffer more. But when there is a flood in the Netherlands, they’re able to change. They can use technology tools for early warning systems. They can build dikes, higher bridges, and other adaptive infrastructure. They’re able to prevent water from flooding their cities. They’re able to save lives.

In Bangladesh every typhoon, every flood event, would kill thousands of people. Bangladesh was more vulnerable, purely based on economic prosperity. Countries like Bangladesh, Pakistan, and many countries in Africa are hard pressed to invest their own resources in adaptation. It competes for funds with development. And what do they choose to pay for? Schools or bridges? What’s the choice?

HPH: So, how do you sell poorer countries on environmental restoration?

Mathai: We’ve taken three major landscapes across Africa to demonstrate that there is a restoration economy to be had, especially for young people. You can have people involved in agroforestry, ensuring that there are trees on farms. Those trees could be fruit trees. Three women who started a macadamia business are incentivizing farmers to put macadamia nut trees on their farms because they are the most prized nut in the world. There’s a wonderful young man who’s growing acacia trees and harvesting gum arabica from them for the cosmetic and beverage industries.

The restoration potential in Africa is the greatest in the world. Seven hundred million hectares (1.73 billion acres) need to be restored. The youngest workforce in the world is on our continent. The role of nature-based solutions to unemployment is huge.

Putting trees on landscapes can be income generating.

HPH: So for you, these two are really intertwined—environment and public health.

Mathai: Moving from public health practice to environmental work, I realized how similar they are. I really came to appreciate the intersection. It just seemed so relevant and important that we would be concerned about the general health of communities rather than the health of individuals. A healthy environment supports healthy people.

Image: Nariman El-Mofty / AP Photo

Filed Under
Leah Samuel
Leah Samuel is a freelance journalist based in Boston.

More in Environmental Health

See all
Marcel Simmons squats on some rocks near the edge of the Flint River. He stares somberly up at the camera.

The children of Flint, ten years later

They'll live with the consequences of the water crisis all their lives. They're angry, but also hopeful. And they've been a rallying point for the city.