In case a vacancy occurs from any cause whatever in the office of governor, the lieutenant governor shall be governor during such vacancy. The compensation of the lieutenant governor shall be prescribed by law. The last elected presiding officer of the senate shall become lieutenant governor in case a vacancy occurs in that office. In case the governor is unable to discharge the powers and duties of his office, the same devolves on the lieutenant governor. The legislature may provide by law for the case of the removal, death, resignation, or inability both of the governor and lieutenant governor to discharge the duties of governor and may provide by law for continuity of government in periods of emergency resulting from disasters caused by enemy attack in this state, including but not limited to, succession to the powers and duties of public office and change of the seat of government.