Indonesia has announced plans to build a new capital city as its current capital, Jakarta, struggles with pollution, traffic gridlock — and the fact that the city is sinking.

After a Cabinet meeting on Monday, planning minister Bambang Brodjonegoro said President Joko Widodo has decided to move the capital out of Indonesia's main island, Java.

It's not clear exactly when this will happen, or where the new capital would be located. The idea has been out there for decades, though previous leaders have been unable to accomplish the ambitious plan.

Earlier this month, Widodo secured another term in office, according to independent polling organizations. His challenger also declared victory, and official results have not yet been announced.

"The idea to move the capital city appeared long ago. ... But it has never been decided or discussed in a planned and mature manner," Widodo said before the meeting, according to The Associated Press.

Jakarta faces massive challenges. As the BBC has reported, it's the fastest-sinking city in the world, with almost half of its area below sea level.

"If we look at our models, by 2050 about 95% of North Jakarta will be submerged," Heri Andreas, an expert in Jakarta's land subsidence at the Bandung Institute of Technology, told the broadcaster.

The president was reported to have considered three possible plans for Indonesia's capital. In the first scenario, according to The Jakarta Post, government offices would move to a special zone near the presidential palace to make it easier for officials to move between meetings.

In the second, the capital would be moved to an area in Java near the current one. Java sits on the western edge of Indonesia's archipelago of thousands of islands. It's the country's most populous island.

Brodjonegoro told reporters Monday that neither of these options would mitigate the crowding in Java, where more than 140 million people live, according to the Post. They ultimately decided on the third option — to locate the new capital outside of Java.

The new capital's location has yet to be announced; the planning minister said his government is looking for a location on the eastern side of Indonesia.

The area of Palangkaraya on the central island of Borneo is also reportedly in the running. Residents there are contemplating what this would mean for their small city.

"I hope the city will develop and the education will become as good as in Jakarta," a high school student told the BBC. "But all the land and forest that's empty space now will be used. Kalimantan [the Indonesian portion of Borneo] is the lungs of the world, and I am worried we will lose the forest we have left."

The planning minister acknowledged that it would take time to implement the idea."This is a big job, impossible to take just one year, it could take up to 10 years," Brodjonegoro said, according to the AP.

Jakarta's problems are largely man-made — the area's large population has extracted so much groundwater that it has impacted the ground levels, and many surface water resources are polluted.

The city's massive amount of traffic is also costly. According to the BBC, the planning minister has estimated traffic jams in Jakarta cost the economy some $6.8 billion annually.

Many other countries have, at some point, moved their capital cities. Nigeria moved its capital from Lagos to Abuja. Pakistan moved its capital from Karachi to Islamabad. Brazil moved its capital from Rio de Janeiro to Brasilia. And Egypt is in the process of building a new capital in the desert.

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