As Borneo’s forests fray at the edges under pressure of development, releasing carbon, it has long been assumed that the untouched forests of the interior remained in a state of relative equilibrium. But new research finds that these old-growth forests are in fact becoming denser, capturing and storing more carbon as a result.

A growing body of evidence suggests that the primary tropical forests of Asia, Africa and Latin America are absorbing more carbon than they are releasing, collectively acting as a global carbon sink. Yet even as they battle the world’s emissions, these forests remain vulnerable to the outside effects of drought, land conversion and climate change.

Hear more from the scientists exploring this topic deep in Borneo’s oldest forests.

• Borneo’s carbon sink
• Long-term carbon sink in Borneo’s forests halted by drought and vulnerable to edge effects
• Atlas of Deforestation and Industrial Plantations in Borneo