Your Old Cell Phone Can Help Save the Rain Forest

National Geographic Explorer Topher White has created a clever way to listen for sounds of illegal logging.

Topher White spends a lot of time walking in—and thinking about—the forest, and how quickly we’re losing it. So much so that he’s gotten a black eye from being smacked by flying tree branches.

But that’s just a small example of what the engineer is willing to endure to stop global deforestation. Founder of the San Francisco-based nonprofit Rainforest Connection, White has developed a simple but ingenious strategy: using old cell phones to listen for the sound of destruction.

Forests are disappearing worldwide, and fast: Swaths half the size of England are lost each year. The Amazon has lost close to one-fifth of its rain forest cover in the last four decades.

Forest loss not only harms wildlife, including many species that live nowhere else, it’s a big contributor to the greenhouse gas emissions that stoke climate change, accounting for about 17 percent of the world’s annual total.

“I didn’t know any of this stuff when I started,” says White, who began his journey in 2011, when he travelled to Indonesian Borneo to help dwindling gibbons.

“I just kind of thought it was about protecting the small areas and animals,” he recently told National Geographic. “But no, [deforestation is] actually one of the biggest contributors to climate change.” 

Between 50 and 90 percent of the logging that happens in the world’s rain forests is illegal, according to White, yet detecting chainsaws and other sounds related to that activity can be tough because the air is already filled with the cacophony of nature.

So he has developed a system in which he rigs a cell phone to stay charged by solar cells, attaches an extra microphone, and listens. From there, the device can detect the sounds of chainsaws nearly a mile away. (His group has details about how to donate your phone here.)

And believe it or not, cell phone reception often isn’t bad in the rain forest. When you’re up in the canopy, “you can actually pick up a signal from pretty far away,” says White, who is also a 2015 National Geographic Emerging Explorer.


Because it’s not feasible to have people listening to the devices all the time, he added some “old-school data analysis,” so that the cell phone’s computers can distinguish a chainsaw’s sound from others in the forest.

White spoke at National Geographic's "Further Base Camp" earlier this year in Austin, Texas.

This way, his device can automatically detect logging activity and send a text alert to authorities who can determine if it’s illegal and then stop it.

On the second day of testing out the idea in Sumatra, Indonesia, White and forest rangers picked up chainsaw noise in the forest. They went to the spot, caught illegal loggers in the act, and talked them out of continuing.

Since then, White has used the devices in Cameroon, Ecuador, and Brazil. Word of his detectors has spread, and demand is so high that White says he’s struggling to make enough to meet demand for them in more than 20 countries. The interest goes beyond logging.

“We’ve already had a lot of requests to use this for gunshot tracking in cities,” he says. The sensors could also be used on oceans to track illegal fishing boats.


White notes that he’s not alone in the fight: Many people and organisations are working tirelessly to stop forests from vanishing.

For instance, indigenous groups are particularly active in forest conservation efforts, White says. 

“If you can just help them do their job more effectively, then you can really cut into the climate change equation. It might be the cheapest, fastest way to stop it.”

Header Image: Topher White set out to preserve Indonesian rainforest like that seen above by monitoring its sounds. PHOTOGRAPH BY MICHAEL NICHOLS, NATIONAL GEOGRAPHIC CREATIVE

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