In 2012, Topher White visited a wildlife sanctuary in Indonesia. He and his fellow volunteers were hiking through the rain forest when they came across a man cutting down a huge tree.
They were watching illegal logging in action. Illegal logging is a big problem in rain forests around the world. It contributes to climate change and destroys habitats for rain-forest creatures.
The logger fled the scene, but the experience bothered White. He knew the wildlife sanctuary employed rangers to watch out for illegal loggers. But the guards hadn’t known about the man White saw. How did they miss him?
White, a trained engineer, thought technology could be part of the solution in the fight against deforestation . “The rain forest is a noisy place, but it’s also a noisy thing to cut a tree down,” he told TIME for Kids. “It struck me that there had to be a way to hear this.”
Over the next few months, White created a device he calls a Guardian. It’s a recycled smartphone powered by solar panels. Guardians can pick up the sound of a chain saw from two-thirds of a mile away. They are mounted on trees, high in the rain-forest canopy.
When a Guardian detects a chain saw, it sends an alert to rangers, indicating where the sound is coming from. The rangers then set off to stop the illegal activity. “If you go that early, if you really respond the moment you get the alert, there’s a chance that you can show up before much of the tree has even been cut,” White says.
White installed the first Guardians in Indonesia, at the wildlife sanctuary where he got the inspiration for the project. Two days later, the devices helped rangers interrupt a logger. “That convinced me others could use this too,” White says.
Since then, White has started a nonprofit group called Rainforest Connection to create and install Guardians all over the world. Rainforest Connection now covers 90,000 square miles of rain forest in 10 countries. Guardians also help protect animals against poaching.
White says he couldn’t have done any of this without local partners. “We’re just tech support for them,” he says. “The people who are really making a difference and fighting climate change are on the ground in the rain forest.”