Indonesia is the world’s largest archipelagic state, a collection of over 17,500 islands stretching across 5,000 kilometers of the equator. This unique geography, featuring over 81,000 kilometers of coastline, has endowed the nation with a vast natural resource base. The immense biodiversity of its terrestrial and marine ecosystems places Indonesia at the center of international environmental discourse. The state of this delicate natural endowment has profound implications for climate regulation and species survival far beyond its national borders.
Indonesia’s Status as a Global Biodiversity Hotspot
Indonesia’s unique positioning between the Asian and Australian continental plates has created a biological richness unparalleled on Earth. The archipelago is bisected by the Wallace Line, a deep-water boundary that separates two distinct biological realms, resulting in an exceptionally high concentration of endemic species. The islands of the Wallacea region, such as Sulawesi, are home to species like the Komodo dragon and the Anoa, a type of dwarf buffalo, found nowhere else in the world.
This terrestrial wealth is mirrored in the surrounding seas, as Indonesia lies at the heart of the Coral Triangle, the global epicenter of marine biodiversity. This area is home to 76% of the world’s known reef-building coral species, numbering around 600, and hosts approximately 2,500 species of reef fish. The country contains 18% of the world’s total coral reefs.
The country also hosts the world’s largest expanse of tropical peatlands, alongside extensive tropical rainforests. These ecosystems are highly specialized, with Indonesia containing about 14% of the world’s tropical peatlands and 22% of its global mangrove forests. The combination of these unique environments solidifies Indonesia’s standing as a globally significant biodiversity hotspot.
The Dynamics of Terrestrial Land Use Transformation
The high demand for agricultural commodities has driven extensive changes in Indonesia’s terrestrial landscape, primarily through large-scale deforestation. The conversion of forest land to commercial agriculture, particularly for oil palm plantations, has been a major factor. Over the last two decades, this expansion has been linked to the loss of approximately 3 million hectares of old-growth forest, representing 57% of the country’s total deforestation during certain periods.
The expansion of oil palm and other resource extraction activities, including mining and logging, often targets vulnerable peatland areas. Indonesian peatlands, which store an estimated 55 to 57 billion metric tons of carbon, are cleared and drained to prepare the land for planting. This drainage and subsequent conversion destabilizes the carbon-rich soil layers, leading to massive emissions.
When drained peatlands are intentionally burned to clear land, the resulting fires create a toxic haze that can blanket much of the region. These fires release immense amounts of stored carbon; the conversion of one hectare of coastal peatland to an oil palm plantation can release carbon equivalent to what was accumulated over 2,800 years. Peatland degradation alone accounted for approximately 40% of Indonesia’s total greenhouse gas emissions between 2010 and 2016, making it a major source of global climate pollution. The severe fire season of 2015, for example, resulted in widespread haze and an estimated economic loss of $16 billion.
Pressures on Marine and Coastal Ecosystems
The pressures facing Indonesia’s land are mirrored in its marine and coastal environments. One visible threat is the massive influx of plastic and marine debris, as the nation is a major global contributor to this pollution. Plastic waste travels from land via rivers and canals, becoming trapped in vulnerable coastal habitats.
Mangrove forests provide natural coastal defenses and serve as nurseries for marine life, but they are particularly susceptible to pollution, as their intricate root systems accumulate debris. These critical coastal ecosystems are also being lost due to drainage for coastal development, aquaculture—such as shrimp farming—and the expansion of agricultural land.
Coral reefs, the most sensitive of the country’s ecosystems to human impact, face degradation from various sources. Coastal development and unsustainable fishing practices contribute to their decline. Climate-induced stressors, such as rising sea surface temperatures, trigger mass coral bleaching events, severely compromising the health of the reefs that support over a quarter of all marine species.
Global Ecological Consequences of Environmental Change
The environmental changes occurring in Indonesia have ramifications that extend far beyond its borders, concerning global climate stability and biodiversity loss. The destruction and fragmentation of tropical rainforests directly threaten numerous endemic and endangered species. Iconic species like the Orangutan, found only in the forests of Sumatra and Borneo, face habitat loss that pushes them closer to extinction.
The Wallacea region, known for its high rate of endemism, harbors 35 critically endangered species, 26 of which are unique to the hotspot. The fate of these populations is tied to the preservation of their rapidly diminishing forest and wetland homes.
Indonesia’s role in global climate regulation is defined by the massive carbon storage within its forests and peatlands, which collectively sequester an estimated 31.2 billion metric tons of carbon dioxide equivalent. The conversion and burning of these lands release this stored carbon, making land-use change a substantial portion of the country’s greenhouse gas emissions and directly contributing to global warming. Indonesia is also highly vulnerable to the consequences of a warming planet. Rising sea levels pose a threat to its many small islands and coastal populations, with approximately 42 million people living in low-elevation areas susceptible to increased flooding and permanent inundation.