– Australia's new Prime Minister Malcolm Turnbull was sworn into power on Tuesday and took charge of a bitterly divided government.

He will carry the weight of expectations that he can lift public opinion, reform a flagging economy and steer the nation on a more moderate course on issues from climate change to gay marriage.

But charting a more centrist course is proving difficult to balance with holding together his riven administration and its wary right wing.

The 60-year-old former journalist, lawyer and merchant banker became Australia's 29th prime minister after his conservative Liberal Party colleagues voted 54-44 on Monday night to replace Prime Minister Tony Abbott only two years after he was elected.

Turnbull's elevation has reinforced a culture of disposable leaders as the new norm in Australian politics since the 11-year tenure of Prime Minister John Howard ended in 2007. Here is a look at his challenges.

ECONOMY

Business groups have welcomed Turnbull's early focus on the economy as a potential boost to business confidence. Turnbull's main charge against Abbott was that he was "not been capable of providing the economic leadership our nation needs." He takes the reins as the economy slows and transitions away from a cooling mining boom that provides 55 percent of Australia's export wealth and has propelled the country into its 25th year of growth. As tax revenue shrinks, a hostile Senate has blocked key spending cuts.

CABINET

The unpopular chief finance minister and budget architect, Treasurer Joe Hockey, was a staunch ally of Abbott who will almost certainly lose the portfolio in a looming Cabinet reshuffle. Finance Minister Mathias Cormann, Defense Minister Kevin Andrews and Employment Minister Eric Abetz could also face demotion for speaking out publicly against the Turnbull coup. Turnbull has given no indication of how sweeping his reshuffle will be when it is announced at the weekend.

CLIMATE CHANGE

Turnbull split the coalition and was voted out as party leader in 2009 over his support for the then-Labor Party government's plan to make polluters pay for their carbon gas emissions through a carbon permit trading scheme.

GAY MARRIAGE

Turnbull, an advocate of gay marriage, changed his view that a bill that would allow same-sex marriage should be voted on before elections due around next September rather than let marriage equality become an election issue. Turnbull told Parliament on Tuesday that he now agreed with the government's position that the same-sex marriage issue should be decided by the public with a direct vote if his government is re-elected.