Australia is missing from the list of countries responsible for triggering the globe's first legally binding deal on climate change.
The Paris United Nations climate change agreement will come into effect next month after countries representing more than half the world's carbon dioxide emitters ratified the deal.
Among them are the European Union - which formally agreed to ratify the deal on Tuesday - China, India and the United States.
But Australia is not included, with the federal government only tabling the agreement in parliament in August.
Parliament's treaties committees is still examining the deal, with a public hearing on Thursday and submissions closing on Friday.
A spokesman for Environment Minister Josh Frydenberg told AAP the government was trying to get it ratified as soon as possible.
As part of Australia's domestic processes, the parliamentary committee was looking at the deal, he said.
The UN's top climate official Patricia Espinosa said the ratification was a "powerful combination" of the importance countries attached to climate change and the realisation of opportunities from the deal.
"The speed at which countries have made the Paris agreement's entry into force possible is unprecedented in recent experience of international agreements," she said in a statement.
Foreign Minister Julie Bishop insists Australia wants to ratify the agreement before the end of the year.
Ms Bishop welcomed the entry into force of the agreement.
"This sends a strong and collective signal of the international commitment to the Paris deal," a spokeswoman for Ms Bishop told AAP.
The July 2 election is being blamed for the delay in tabling the agreement, which was struck in Paris last December.
The government tabled the agreement at the first possible opportunity following the election.
But the Greens say it's appalling Australia is trailing the world on ratification.
"While the rest of world is moving, the Turnbull government hasn't ratified the climate agreement and instead has declared war on renewable energy."
Recent damaging storms in South Australia that triggered a statewide blackout have sparked a debate about the impact of high renewable energy targets on grid security.
The Paris agreement comes into effect 30 days after 55 per cent of the world's emitters ratify it but doesn't apply until 2020.
The EU is the 63rd party of 196 to ratify the deal.
The agreement requires parties to submit a national emissions reduction target every five years with the goal of keeping global warming increases below 2C.
