Sydney - Australia ratified the Paris climate agreement on Thursday, amid fears US president-elect Donald Trump could follow through on his pledge to "cancel" the landmark pact aimed at tackling global warming.More than 100 nations representing 70% of greenhouse gas emissions have inked the historic Paris Agreement, the world's first universal climate pact, which came into force in early November.Australia's approval of the binding deal was delayed by national elections in July and its announcement Thursday came ahead of the departure of the country's foreign and environment ministers for UN climate talks in Marrakesh."Ratification of the agreement confirms Australia's ambitious and responsible target to reduce emissions by 26 to 28% below 2005 levels by 2030," Prime Minister Malcolm Turnbull said in a joint statement with the two ministers."We are on track to meet and indeed beat our 2020 targets... and are committed to meeting our 2030 targets under the agreement."With its heavy use of coal-fired power and relatively small population of 24 million, Australia is considered one of the world's worst per capita greenhouse gas polluters.When asked if Canberra would follow the United States if it exited the treaty, the prime minister stressed Australia's commitment to the "watershed" agreement."We have ratified the agreement. It will - it takes four years to withdraw - if a country sought to withdraw from the agreement it takes four years," he told reporters."Secondly, this is a global agreement. When Australia makes a commitment to a global agreement, we follow through and that is exactly what we are doing."Ban new coalEnvironmental groups welcomed the ratification but said Australia needed to do more."There's no way Australia can continue to approve new fossil fuel projects and keep the commitments it has just made," Greenpeace Australia's Pacific climate and energy campaigner Shani Tager said in a statement."As the world's largest exporter of coal, the world's most dangerous fossil fuel, Australia's first step to meeting this promise must be a ban on new coal mines."Climate change denier Trump, who has made no secret of his disregard for the United Nations, pledged earlier this year to withdraw from the Paris climate deal. In contrast, current US President Barack Obama has been a champion of the pact.The US is the world's second-largest greenhouse gas polluter after China, producing 13 percent of global emissions.France's environment minister and outgoing head of the UN climate forum Segolene Royal said Wednesday that Trump "cannot prevent the implementation" of the pact."He cannot - contrary to his assertions - undo the Paris Agreement," she told French radio station RTL.