Ngoc Anh of Vietnam knows the value of trees.
For years, he worked as a logger.
He cut trees down illegally to sell as timber.
He often worked with others to carry 100-kilogram logs out of a quickly thinning forest.
But very high rainfall and floods increasingly damaged his community in the central province of Quang Binh.
The 36-year-old Ngoc started reading about the climate and nature crises.
He changed his work and became involved in tourism and environmental conservation.
Now, Ngoc Anh is one of 250 former loggers to receive training from a tourism company.
He works as a travel guide.
He mostly leads foreign tourists through forests and into some of the world's largest caves in the Phong Nha-Ke Bang National Park.
"Before, whenever I saw a large tree, my head calculated how tall the tree was and how to cut it into logs of different sizes."
Ngoc Anh said, "But now that I'm in the tourism business, when I see such a tree, I tell the tour group how valuable this tree is because there aren't many left."
Global Forest Watch estimates that Vietnam lost about 3 million hectares of tree cover between 2001 and 2020.
That is a 20 percent decrease in 20 years.
The losses were mostly driven by logging.
In 2007, the government started taking more measures to prevent illegal logging, which has helped slow the rate of deforestation.
Vietnam has also joined an international promise to end deforestation by 2030.
Joined by a park official, Ngoc Anh and other tour guides help guard the trails to keep poachers away.
They remove animal traps and clean up any waste.
Ngoc works for less than half the money of what he earned as a logger.
But he hopes to earn more as tourism and travel return to Vietnam.
I'm Jill Robbins.