Here’s How Tropical Lands Can Self-Recover

According to a recently published study, 215 million hectares of degraded and deforested tropical land could recover independently. This is more cost-effective than tree planting and greatly benefits biodiversity and climate.

“The nice thing about what we’re proposing is that it’s incredibly cheap relative to planting trees,” explains study co-author Matt Fagan, associate professor in geography and environmental systems at the University of Maryland. “Here’s areas that, if you just let them go, will pop back into rainforest quickly. It’s incredibly impressive. [At] 3 years old, it’s over your head; 5 years, you’re under shade.”

For their study, the team developed a model based on satellite images of where forests had regrown, going as far as using machine learning to filter out places where humans had planted trees. Biophysical variables like rainfall, fire frequency, and the distance from the edge of the standing forest have been considered. Tree planting is crucial to restore 30% of the world’s degraded land by 2030 – a target of the 2022 Global Biodiversity Framework signed by 196 countries – but scientists believe that natural regeneration plays an equal part in achieving this goal. Brazil holds the most tropical forest with 43.7 million hectares, and combined with China, Colombia, Indonesia, and Mexico; they could account for 52% of the land that could regenerate forests naturally. The 215-million-hectare area would pull 23.4 billion metric tons of carbon from the atmosphere in 30 years.