Minister of the Environment (Australia) gas emissions, and promoting energy efficiency. The following individuals have been appointed to the post, or any of its precursor titles: The Minister for Sustainable Population was a ministerial portfolio administered through the Department of the Treasury responsible for "planning properly for the infrastructure needs, for the housing needs, for the transport needs, for the regional needs" of the Australian population of the future. Originally entitled the "Minister for Population" by Prime Minister Kevin Rudd, his successor, Julia Gillard, renamed the portfolio to the "Minister for Sustainable Population" to reflect her policy changes on the matter of population growth and
Acting prime minister is on vacation, or is in ill health. In the early 20th century, when travel by ship was still the norm, it was not uncommon for there to be an acting Prime Minister for months on end. The deputy Prime Minister is usually designated as the acting Prime Minister, although another senior member of the government may fill the role if both the Prime Minister and deputy Prime Minister are unavailable. An acting Prime Minister is required quite frequently – for instance, between 3 December 2007 and 23 February 2009 (during Kevin Rudd's first term), Julia Gillard acted as Prime