ABC Fact Check
The United States and China announced a major new agreement on climate change on the sidelines of the recent APEC meeting in Beijing.
US president Barack Obama set a target of a 26 to 28 per cent cut in 2005 levels of the USA's greenhouse gas emissions by 2025, while president Xi Jinping of China committed his country to see carbon dioxide emissions peak by 2030.
The surprise deal came just days after US president Barack Obama's Democratic Party lost its majority in the US senate, casting doubt on his ability to pursue his policy agenda.
Australian Treasurer Joe Hockey says it will be difficult for Mr Obama to deliver on his pledge.
"Barack Obama has to get any initiative on climate change through a hostile US congress... I mean, that's up to the US, but so far he hasn't had great success," Mr Hockey told ABC TV's Insiders.
ABC Fact Check asked the Treasurer for the basis of his claim. A spokesperson said: "We have no details of how the US plans to appropriate the money, but money spent by the US government must be appropriated through the proper processes. These appropriations are subject to the review of congress — as such the Treasurer's statement is entirely correct."
Fact Check examines the Treasurer's claim that Mr Obama needs the support of congress to fulfil the agreement with China.
The American president and the congress
Unlike Australia's system where the party with the majority in the House of Representatives forms government, under the American system there are separate elections for the house of representatives, the senate and the presidency. That means the party which holds the presidency doesn't always have the majority in the house or senate (which together make up the congress). This is often described as "divided government".
Mr Obama was elected to a four-year term in November 2008 and re-elected to a second term in 2012, meaning he will stay in the White House until early 2017.
Following the November 2014 "midterm" elections, Mr Obama's rival Republican Party extended its majority in the house and won a majority in the senate. That means Mr Obama's Democrats can't pass legislation without some bi-partisan support.
The Republican Party is also limited in what it can do legislatively. Democrats can use the filibuster to stop any bill passing the senate, and the president can veto any legislation passed by congress that he doesn't agree with.
The president is also able to issue executive orders, which have the power of federal law, unless they are successfully overturned by congress or the supreme court.
It is through executive orders that Mr Obama will have the Environmental Protection Agency (EPA) work to cut emissions.
Pollution and the Environmental Protection Agency
While attending the G-20 leaders' summit in Brisbane, Mr Obama was asked by a reporter about his use of executive orders to go around an obstructionist congress.
With respect to the climate agreement, he said: "The goal that we have set, a 26 to 28 per cent reduction by 2025, we shaped that target based on existing authorities rather than the need for additional congressional action. That's based not on particular executive actions that I am taking, but based on the authority that's been upheld repeatedly by this supreme court for the EPA — the Environmental Protection Agency — to be able to shape rules to be able to regulate the emission of greenhouse gases."
The president went on to talk about other measures to help meet the target, including the doubling of fuel efficiency standards for motor vehicles, which were agreed with car makers as part of a government bailout of the auto industry during the global financial crisis.
It created extensive powers for the regulation of air pollution and the creation of emissions standards. In December 1970, the EPA was formed to implement and enforce the new standards.
In 2009 Mr Obama's Democrats attempted to enact a legislation to "cap and trade" carbon emissions, but it failed to pass the senate.
In 2013 the president announced he would bypass congress and take executive action to reduce carbon pollution, using the regulatory powers of the EPA and other agencies.
In June 2014, US supreme court issued a ruling in the case of Utility Air Regulatory Group vs. EPA, which affirmed that greenhouse gas pollution from stationary sources was subject to EPA permits under the Clean Air Act.
One of Mr Obama's leading critics on climate policy, Republican senator Jim Inhofe of Oklahoma, has vowed to fight what he calls "overbearing EPA mandates". Senator Inhofe, a senior member of the senate Environment and Public Works Committee and a climate sceptic, says he will do everything in his power to "rein-in and shed light on the EPA's unchecked regulations".
'The heavy lifting is already done'
Unlike a formal treaty such as the Kyoto protocol, the climate agreement with China doesn't have to be ratified by the US senate, according to Norm Ornstein, resident scholar at the American Enterprise Institute, a conservative think-tank.
Bruce Wolpe, a former adviser to Democrats in the house of representatives in Mr Obama's first term, believes the EPA has the power to impose standards to meet the president's goal. "The supreme court has ruled that carbon pollution can be regulated by EPA under the Clean Air Act. That's the authority he has used and will use now," Mr Wolpe said.
Dr Thomas Mann, a leading congressional scholar at the Brookings Institution, a progressive public policy think-tank in Washington D.C, says Mr Obama is likely to go around congress. "I don't expect Obama to even submit any such initiatives to congress," he said.
"His actions on climate change since 2009 have and will be entirely executive and administrative."
The author of a 2008 study on the economic impact of climate change in Australia, economist Professor Ross Garnaut, is in no doubt Mr Obama can deliver on his targets without the support of the US congress.
Speaking on ABC TV's Lateline program, Professor Garnaut said: "President Obama doesn't need the new congress to deliver on his targets, just as he didn't need the congress to deliver on his ambitious targets of reducing emissions by 17 per cent between 2005 and 2020."
Dr Mann agrees. "The professor is correct. Most of the heavy lifting is already done; the rest to follow soon," he said.
'Tug-of-war' between Obama, Republicans
While experts agree Mr Obama has the power to circumvent congress and order the EPA to impose tougher emissions standards, and the EPA has the remit to do so, there is still the question of money.
Dr David Smith from the United States Studies Centre at the University of Sydney says while executive orders don't have to "go through" congress, Republican congressional leaders have already suggested they will use their expanded power to fight any climate initiative, such as threatening to defund the EPA if it enforces new regulations. Dr Smith says while Mr Obama can go around congress with many new climate initiatives, including the deal with China, congress can still try to make it difficult to implement any of those initiatives.
Yet Mr Wolpe, who was also an advisor to the Australian Labor government, says while Republicans in congress could pass a law denying the use of government money for the EPA to process the emissions regulations, or a law to terminate the EPA's ability to act in these areas, he says the president could veto any such restriction.
And Mr Wolpe says as it takes a two-thirds vote in both the house and senate to override the veto, there are still enough Democrats to ensure that the override would fail, and the EPA can keep "going about its business" regulating greenhouse gas emissions.
However, others see a longer showdown looming.
Scot Faulkner was an adviser to Republican house speaker Newt Gingrich in the 1990s and became the chief administrative officer of the house of representatives. Mr Faulkner says the president, as head of the executive branch, can direct any agency such as the EPA to do anything, However he says: "Congress can hold him in check if any of these actions require the use of public funds. The legislative branch's 'power of the purse' trumps all."
Having the "power of the purse" means congress can alter or stop the passage of appropriation bills to fund agencies such as the EPA and even shut down the federal government, which they did in 2013.
As a result, Professor James McCormick, a political scientist from Iowa State University says, "the Republicans would structure the funding in a way to prohibit certain activities by the EPA".
Dr Ornstein says that will result in a "tug-of-war between Obama and the Republicans in congress".
Dr Smith says who would win that "tug-of-war" is a matter of political will, political capital and stamina.
"This could set up another government shutdown scenario, in which Republicans challenge Obama to let the government shut down for the sake of keeping his environmental agenda alive," he said.
"That would be very politically risky in the lead up to the 2016 [presidential] election."
But Dr Smith says given that the 2013 shutdown doesn't seem to have hurt Republicans in the 2014 midterms, there will certainly be elements of the Republican Party who want to try it.
The executive powers of the president, and the ability of the Environmental Protection Agency to impose stricter emissions standards are well established.
The agreement with China does not have to be ratified by congress.
However, Republicans in congress could try to limit funding to the EPA, and that could trigger another government shutdown.
Mr Obama does not first have "to get any initiative on climate change through a hostile US congress" as Mr Hockey suggests.
But there are still questions over Mr Obama and EPA's ability to deliver on the climate deal without support from congress.
Mr Hockey's claim is overstated.
This article was originally published at ABC Fact Check