Where Is the Borneo Rainforest? Three Countries Share the World's Third-Largest Island

The Borneo rainforest covers most of Borneo, the world's third-largest island (743,330 km²). Politically, the island is divided among three countries:

• Indonesia (73%): Kalimantan — five provinces. Largest share; highest deforestation (palm oil, mining, fires).
• Malaysia (26%): Sabah and Sarawak states. Better protected; major ecotourism (Kinabalu, Mulu, Sepilok).
• Brunei (1%): Entire country on north coast. Wealthy, oil-funded; ~70% forest cover retained.

Ecological Significance

• 130 million years old—oldest rainforest.
• 15,000+ plant species (6,000 endemic); 3,000+ tree species (Dipterocarps dominate).
• Iconic fauna: Bornean orangutan, pygmy elephant, proboscis monkey, clouded leopard, sun bear, 600+ birds.
• Peat swamp forests: massive carbon stores; burning releases gigatonnes CO₂.

Threats

• Palm oil plantations (Indonesia/Malaysia #1/#2 global producers).
• Logging (legal/illegal), mining, infrastructure.
• Fires (El Niño + drainage = catastrophic).
• Climate change: drought intensification.

Conservation

• Heart of Borneo Initiative (transboundary 220,000 km²).
• Protected areas: Kinabalu, Gunung Mulu, Tanjung Puting, Betung Kerihun, Kayan Mentarang.
• RSPO (sustainable palm oil), FSC timber, REDD+ projects.

Borneo's rainforest is a planetary asset managed by three nations. Its future depends on cross-border cooperation valuing standing forest over cleared land.