Indonesia’s New Capital on Borneo: A Forest at a Crossroads

When I first set foot on the steep, moss‑slick slopes of Mount Tembinus, the air smelled like wet earth and fresh leaves. My guide, Abidi—his name a gentle reminder of the generations that have tended these hills—wore a beaded hat and a cigarette that seemed glued to his lips. He led me past waist‑high ferns, past a clump of elephant‑ear plants that could easily swallow a small child, and finally to a lone tree where a small black box was perched like a nervous bird.

That box, stamped with the word "Swift," is nothing more than a rugged, weather‑proof recorder. It sits there, humming quietly, its tiny microphone catching every rustle, every chirp, every distant crash of a woodpecker on bark. Abidi nudged it gently, swapped out the battery and the SD card, and said, "These devices are like a diary for the forest. They keep the stories of our ancestors alive, so our children can hear them too."

He wasn’t exaggerating. For the past 18 months the recorder has been listening nonstop, documenting a chorus of life that scientists fear will soon be muffled by machines. The reason? Indonesia’s bold decision to carve a new capital—Nusantara—out of the very rainforest where the recorder lives.

Jakarta, the current capital, is sinking faster than most cities on the planet. Decades of groundwater pumping—an ugly legacy of Dutch colonial water distribution that left only elite neighborhoods with piped water—have turned the city’s foundation into a bathtub draining away. In some districts the ground slips a foot each year, and rising seas only add insult to injury. By 2050, experts warn, half of Jakarta could be underwater.

Faced with that bleak forecast, President Joko Widodo (Jokowi) announced in 2019 that Indonesia would relocate its seat of power. The chosen site? A sprawling 256,000‑hectare parcel in the highlands of Eastern Borneo—about three times the size of New York City. The land is covered mostly by an industrial eucalyptus plantation, but the plan is to transform it into a "forest city" that runs on electricity and renewable energy, with plenty of green corridors and walkable streets.

The name, Nusantara, simply means "archipelago" and is meant to signal a more inclusive future, moving the political centre away from Java’s dense, polluting sprawl to a spot that sits roughly in the middle of the nation’s islands. The vision sounds almost utopian: sleek glass towers sprouting like saplings, elevated walkways that let rainwater flow naturally, wildlife corridors that let pangolins and gibbons wander safely. All of this is slated for completion around 2045, and the city is designed to house just a quarter of Jakarta’s population—about 2.5 million government workers.

But while the glossy renderings promise harmony, the reality on the ground is messier. The construction of roads, utilities, and a massive sea wall along Java’s north coast—budgeted at $80 billion—means bulldozers will start carving into a forest that’s home to some of the world’s most diverse flora and fauna. Even the eucalyptus trees, already non‑native, are being cleared to make way for the new urban grid.

Enter the scientists. Wendy Erb, a primatologist and bioacoustic specialist at the Cornell Lab of Ornithology, has spent two decades in Indonesian rainforests. She says, "We’re trying to document what’s here before the landscape changes beyond recognition. Sound is a non‑invasive way to capture biodiversity—every frog call, every insect buzz tells us something about the health of the ecosystem."

Alongside local Indigenous collaborators, Erb and her team set up dozens of recorders—some perched high in the canopy, others nestled on the forest floor. Their goal is simple yet urgent: create an audio library that future generations can use to understand what once thrummed through these woods. It’s a race against time, because as roads cut deeper and heavy machinery arrives, the very acoustic environment they’re trying to preserve will be altered.

There’s also a human element. For people like Abidi, the forest isn’t just a backdrop for scientific curiosity; it’s a living memory. "My grandparents farmed these slopes," he told me, gesturing to the rolling mist. "When the trees fall, it feels like a part of us disappears."

The Indonesian government says the new capital will be a model of sustainability, that the forest will be integrated into the city’s design, with green belts and protected zones. Critics, however, point out that the sheer scale of development makes such promises hard to keep. The balance between progress and preservation remains fragile, and the forest’s fate may hinge on how well policies translate into practice.

For now, the recordings keep rolling. In the evenings, when the sun dips behind the hills, the forest sings—a chorus of cicadas, a distant orangutan call, the rustle of leaves as a gentle wind sweeps through. Those sounds, captured on tiny metal boxes, may become the only evidence of a world that once was, should the concrete inevitably claim the canopy.

Whether Nusantara will become the shining example of a city that lives in harmony with nature, or a cautionary tale of ambition overrunning ecosystems, is still uncertain. What is clear is that the forest is already paying a price, and its voice—if we listen—has a lot to say about the choices we make today.