The high population, which is growing, may however be a threat to sustainability due to depletion of resources and resultant resource scarcity. High population density, especially with cities that lack proper planning, is also a threat to living standards and welfare because of compromised garbage and sewage systems and this has potential adverse effects to resource allocation and utilization for sustainable development. Dynamism among the cities is another factor to sustainable development and while dynamism in economic activities promotes economic development, unplanned activities such as land use undermine future developmental prospects. Planned ventures as realized in “settlement, infrastructure, and land tenure” however ensure planed approach to sustainable development of the mega cities and emerging cities. Increased significance of social and economic gap, as people converge in the cities, is however a source of conflict and a threat to present and future development. Poor governance, compared to developing complexity levels in mega cities is another threat to the cities’ developmental prospects (Kotter, 2004).
While effects of development and expansion of mega cities offer developmental prospects, some of its factors are a threat to sustainable development and development and implementation of strategies for managing the threats are recommended.