Pollution goals in peril: the US pull-out of the Paris climate accord could set back global efforts to curb greenhouse gas emissions. Credit:Getty Images "I think there is still very broad-base support for the commitments that were made and certainly Australia takes its international commitment seriously," Frydenberg told Sky earlier this week. The PM has said "when Australia makes a commitment to a global agreement, we follow through and that is exactly what we are doing". But the Turnbull government can be expected to come under renewed pressure from right-wing Coalition MPs and their media boosters to follow Trump's lead if the US pulls out. To be sure, Trump seeking to trash the Paris deal isn't entirely a surprise given he campaigned on that course, famously tweeting that climate change was a "hoax" concocted by the Chinese to undermine the US economy. But Trump has broken any number of promises in his four months in office (including taking a tough stance against China on trade). And the reported pro-environment overtures by his daughter Ivanka and even Pope Francis' personal appeal during last week's visit to the Vatican stoked hopes Paris might get a last-minute reprieve.

US President Donald Trump and Pope Francis at the Vatican in May. Credit:AP The consequences of a Paris without America will take time to play out. Some analysts had worried that a US administration hell-bent on boosting fossil fuel industries might have become a wrecker if left within the treaty – a type of Saudi Arabia on steroids. The impact on Paris would not only be confined to the bad example set by a nation responsible for about a quarter of accumulated carbon emissions. The existing Paris commitments only curb warming to about 2.5 to 3 degrees, and nations are supposed to ratchet their emissions trajectory lower at five-year intervals to meet the sub-2 degree goal. As the richest nation, the US was expected to provide a sizeable chunk of the US$100 billion ($134 billion) a year in public and private financial flows to developing nations by 2020. The funds would help them cut emissions and adapt to the changing climate which they had done little to cause, but are often the most vulnerable to. With less chance of those funds being found, many of those poorer nations will be unable to commit to greater climate action even if they were willing.

As Stefan Rahmstorf - head of Earth System Analysis at Germany's Potsdam Institute for Climate Impact Research - stresses, there is a given budget of greenhouse gases that can be emitted to keep warming under 2 degrees to avoid dangerous climate change. "The more we have emitted in total, the warmer it will be - with all the detrimental impacts, from sea-level rise to extreme weather to dying corals," he tells me. "If the US uses more of this budget, others can use less." Ahead of the expected Trump exit, some analysts were pinning hopes on the European Union – suddenly needing to become a lot more united amid Britain's planned exit and increasingly fraught ties with the Trump administration – teaming up with China to reinvigorate the Paris agreement. The US, they say, will have far more to lose by abandoning the huge emerging energy technologies, particularly for renewables and storage. Moreover, the US would be inviting retaliation in the form of "carbon tariffs" on its exports to markets of those remaining in the Paris accord. But as Malte Meinshausen, director of Melbourne University's Climate & Energy College, notes the damage from such a move would be unlikely to be contained to climate-only matters.

Loading "The damage to the international diplomatic multilateral system within the UN will be substantial - and outweighing the potential benefits that an US withdrawal from Paris might have [compared to a residing, but destructive US]," Professor Meinshausen says. "That can play out in peace talks, economic cooperation, WTO, et cetera. "The potential ramifications of undermining a globally almost-unified response to a common challenge by a 'rogue superpower' are hard to predict at this point," he says.