Some environmental disasters announce themselves: a spill draws cameras, an apology, a cleanup crew. Most do not. They begin instead as paperwork — a mining permit, a revised land-use map, a supply contract signed in some distant boardroom. By the time anyone notices, the damage is already done. In Indonesia, it is often done at the scale of mountains.
That is what is happening now to the karst — the porous limestone hills, honeycombed with caves and underground rivers, that run through Sulawesi and neighboring Halmahera in eastern Indonesia. These formations filter rainwater into the clean springs that many rural communities depend on.
The industry eating into it is the Chinese-led nickel boom that has made Indonesia the backbone of the world’s electric-vehicle battery and stainless-steel supply chains. What gets far less attention is that this boom runs on limestone — and that the limestone is being torn from some of the region’s last intact karst.
Indonesia now has 147 nickel-processing plants operating or under construction. About 120 use a method called RKEF, which requires quicklime — made by heating limestone — to burn impurities out of the ore in a furnace.
The remaining 27 use a chemical process called HPAL, which requires even more limestone to neutralize the sulfuric acid that dissolves the ore. Neither method works without a steady, nearby supply of limestone — which is why new quarries keep opening around every major smelting hub in Sulawesi and Halmahera.
Chinese companies built and now run most of these hubs. Tsingshan Holding Group, the world’s largest stainless-steel maker, anchors the Indonesia Morowali Industrial Park in Central Sulawesi — a flagship Belt and Road project that reportedly operates its own lime plants on site, alongside its smelters.
CNGR Advanced Material, a Chinese battery-materials producer, also operates inside Morowali and has built a nickel plant inside the Weda Bay Industrial Park on Halmahera, roughly 700 kilometers to the east — making it one of the few firms with a foothold in both of Indonesia’s largest nickel hubs.
Around them sit other Chinese ventures. GEM Co., Zhejiang Huayou Cobalt and CATL’s Bangpu affiliate process battery material at Morowali, while Ningbo Lygend, in partnership with Indonesia’s Harita Group, does the same on Obi Island.
Chinese firms are estimated to control more than three-quarters of Indonesia’s nickel-refining capacity — meaning the demand curve for limestone across the region is being drawn largely in Chinese boardrooms.
Nowhere is the gap between industrial demand and legal protection starker than in the Banggai Islands, off Central Sulawesi, where the energy ministry has marked out 38 permit areas for limestone quarrying.
By April 2026, 23 of those had become full business permits, with five already producing. Back in 2023, the environmental group WALHI had counted 28 companies applying for limestone-quarry permits across nine districts.
This is happening despite the fact that, on paper, the Banggai Islands enjoy some of the strongest legal protections of any karst landscape in Indonesia. A 2019 regional regulation protects the islands’ karst outright. A 2022 decree from the local government designates the area as a high conservation zone, complete with maps and coordinates.
In April 2026, the Central Sulawesi provincial parliament asked the governor to cancel every limestone permit on the islands and freeze new ones, arguing that they violate both rules. The request has reportedly sat on the governor’s desk ever since, unanswered.
A similar pattern is emerging around Sagea, a karst area beside the Weda Bay park that is home to the Bokimoruru cave system and a river local communities depend on for drinking water. Limestone and nickel permits already cover much of that watershed.
The authors are investigating claims that limestone bound for Weda Bay is being quarried by a CNGR subsidiary, and that CNGR’s Morowali operations have drawn financing from Bank Central Asia, Indonesia’s largest private lender.
Neither claim has been independently confirmed. But both fit a wider pattern: the same handful of Chinese firms that dominate Indonesia’s nickel industry keep turning up near its most threatened karst.
Jakarta markets this whole industry as green — a contribution to the global fight against climate change through electric-vehicle battery production. Communities in Sulawesi and Halmahera see something closer to an old arrangement dressed in new language: a decarbonization push abroad that deepens extraction at home instead of easing it.
Karst is not simply rock waiting to be blasted. It functions as a vast natural filter: rain seeps through crevices and underground channels built up over millions of years, and emerges on the other side as the clean spring water that communities have relied on for generations.
No technology available today can undo damage to that system. Treating limestone as a generic input — with no history and no community attached — makes the destruction easier to overlook, and easier to repeat, permit by permit, under the banner of an industry still being sold as clean and green.
Viky Arthiando Putra is a researcher at the Center of Economic and Law Studies (CELIOS), an independent research institute based in Jakarta. Muhammad Zulfikar Rakhmat is director of the China-Indonesia Desk at CELIOS.
