(a) A city may by ordinance define, prohibit, regulate, or abate acts, omissions, or conditions, detrimental to the health, safety, or welfare of its citizens and the peace and dignity of the city, and may define and abate nuisances.
(b) A city ordinance shall be consistent with the Constitution and laws of North Carolina and of the United States. An ordinance is not consistent with State or federal law when:
(1) The ordinance infringes a liberty guaranteed to the people by the State or federal Constitution;
(2) The ordinance makes unlawful an act, omission or condition which is expressly made lawful by State or federal law;
(3) The ordinance makes lawful an act, omission, or condition which is expressly made unlawful by State or federal law;
(4) The ordinance purports to regulate a subject that cities are expressly forbidden to regulate by State or federal law;
(5) The ordinance purports to regulate a field for which a State or federal statute clearly shows a legislative intent to provide a complete and integrated regulatory scheme to the exclusion of local regulation;
(6) The elements of an offense defined by a city ordinance are identical to the elements of an offense defined by State or federal law.
The fact that a State or federal law, standing alone, makes a given act, omission, or condition unlawful shall not preclude city ordinances requiring a higher standard of conduct or condition.