Founder’s Briefs: An occasional series where Mongabay founder Rhett Ayers Butler shares analysis, perspectives and story summaries.
June 22 marks World Rainforest Day, launched in 2017 by Rainforest Partnership to highlight the critical role of tropical forests. These ecosystems stabilize the climate, regulate rainfall, store vast amounts of carbon, and support most of the world’s terrestrial biodiversity. Yet despite their importance, 2024 proved to be a devastating year. Fires ravaged millions of hectares, and several regions experienced record levels of primary forest loss.
Here’s a snapshot of the 10 largest tropical rainforest regions:
- Amazon
The Amazon is Earth’s largest rainforest, essential to continental rainfall patterns and global climate regulation. Renowned for its rich biodiversity and Indigenous cultures, more than half of the tropics’ primary forest lies here. It also accounts for the greatest loss — nearly 44 million hectares (109 million acres) since 2002, an area roughly the size of Iraq. Fires in 2024 hit Brazil and Bolivia especially hard.
- Congo Basin
Home to gorillas, bonobos and the elusive okapi, the Congo rainforest spans Central Africa, with 60% located in the Democratic Republic of Congo. Deforestation remained relatively low until the 2010s, but has surged in recent years.
- New Guinea & Northern Australia
New Guinea, the world’s second-largest island, is a biodiversity stronghold with species found nowhere else — like tree kangaroos and cassowaries. Though still among the least-disturbed major forest regions, threats from oil palm expansion, mining and logging are rising.
- Sundaland
Comprising Borneo and Sumatra, this region has seen the highest proportional forest loss since 2000 due to industrial plantations. It’s a critical habitat for rhinos, orangutans and other iconic species.
- Indo-Burma
Stretching across parts of mainland Southeast Asia, Indo-Burma features diverse forest types and iconic wildlife including tigers and Asian elephants. Human pressure has led to widespread fragmentation and degradation.
- Mesoamerica
From southern Mexico to Panama, Mesoamerica’s rainforests are hotspots for birds and amphibians. Deforestation, driven by agriculture and fire, is accelerating in some areas.
- Wallacea
Indonesia’s Sulawesi and nearby islands are home to highly endemic species. Forest loss has increased due to plantations and infrastructure development.
- Guinean Forests of West Africa
Heavily impacted by agriculture and logging, these forests are fragmented, but the remaining patches are still ecologically rich.
- Atlantic Forest
Once stretching along Brazil’s coast into Argentina and Paraguay, the Atlantic Forest has lost more cover than any other region listed. Restoration efforts are now underway.
- Chocó-Darién
Running from Panama to northern Ecuador, this is the world’s wettest rainforest — and the least deforested among the major tropical zones.
The outlook is sobering, but not yet hopeless. Many rainforests can still be saved if immediate action is taken. Political will, sustained funding and strong governance are essential. Indigenous and local communities, proven stewards of these ecosystems, must lead the way. On this World Rainforest Day, the message is urgent: time is short, but there is still a path forward.
Banner image of a squirrel monkey in the Colombian Amazon by Rhett A. Butler/Mongabay.
