They can try but Like New York City found out. Even it could not comply with their own stupid regulations.

I guess they could on a city level such as street lights, city government offices and public parks and stuff but I don’t think they can “make” the general population do anything like that. Many towns have tried to make recycling mandatory and it has failed many times. It just gives the scrap and aluminum can hunters easy pickings.

They cannot legally impose their will on you but they may suggest or give you incentive to do so.

Depends on the powers of the mayor in that particular city. I think ordinances are usually voted on by the city councils typically.

Given that Houston’s industries include chemical and petrochemical… do you want them to put up wind mills, solar panels or something?