Agenda 21 has become a big issue with conspiratorialists. The claim is that this UN program will lead to destruction of sovereignty for this and other nations in the name of "sustainability." The reality is this UN program simply has no teeth. Lots of localities are voluntarily joining this sustainability campaign because the world needs some sort of environmental direction.
Agenda 21 is a form of world government. While the ideas of decreasing poverty and helping are good, different nations and local communities should have the freedom to decide for themselves on such matters. They would know better what is best for themselves, and they are nations and have government for a reason.