Explain how supranational organizations such as the United Nations can support urban sustainability

By creating cooperative effort between several nations to invest in affordable energy

Explanation:

Urban sustainability refers to a situation when heavily populated area can continue its operation without the threat of running out of resources/power.

This condition can be achieved if we managed to improve clean energy (such as electricity generator from sun light, or very safe nuclear). Currently, all of the available method to get clean energy are either very expensive or dangerous.

Supranational organizations such as the United Nations could initiate a program that gathered all of the top experts from all over the world, to work together to find out the solution of this energy problem.