Dhaka, Bangladesh
Predicted increase in population by 2025: 6.29 million
As the central hub of Bangladesh, the newly minted megacity of Dhaka stands as the country's political and business center. The city has increasingly enveloped the surrounding rural towns as each year more than half a million laborers relocate from elsewhere in Bangladesh to the capital. The good news is foreign and domestic investment is bustling, but scientists fear that the city will not be able to support such a population explosion. Dhaka is three times larger than Bangladesh's second largest urban area of Chittagong and is already bursting at the seams. Additionally, the city's precarious location in the low-lying Ganges delta, coupled with a poor drainage system, makes the area prone to flooding during the monsoon. But despite its problems, the city is undeniably where the majority of job opportunities in the country reside — including 75% of the nation's factory jobs. In an attempt to curb the rapid urbanization, the government is in the process of implementing a tax holiday for new constructions outside the city.