“This is a momentous occasion,” said Mr. Ban as the latest instruments of ratification were accepted in deposit.

“What once seemed unthinkable, is now unstoppable. Strong international support for the Paris Agreement entering into force is a testament to the urgency for action, and reflects the consensus of governments that robust global cooperation, grounded in national action, is essential to meet the climate challenge,” he added.

But he cautioned that the work of implementing the agreement still lay ahead. “Now we must move from words to deeds and put Paris into action. We need all hands on deck – every part of society must be mobilized to reduce emissions and help communities adapt to inevitable climate impacts,” he stressed.

Adopted in Paris by the 195 Parties to the UN Framework Convention on Climate Change (UNFCCC) at a conference known as COP21 this past December, the Agreement calls on countries to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low-carbon future, as well as to adapt to the increasing impacts of climate change. Specifically, it seeks to limit global temperature rise to well below 2 degrees Celsius, and to strive for 1.5 degrees Celsius.

The pact – which was signed in New York on 22 April by 175 countries at the largest, single-day signing ceremony in history – will enter into force 30 days after at least 55 countries, accounting for 55 per cent of global greenhouse emissions, deposit their instruments of ratification, acceptance or accession with the Secretary-General.

The requirements for entry into force were satisfied today when Austria, Bolivia, Canada, France, Germany, Hungary, Malta, Nepal, Portugal and Slovakia, as well as the European Union, deposited their instruments of ratification with the Secretary-General.

Earlier this week, New Zealand and India signed onto the Agreement, following the 31 countries which joined at a special event at the UN on 21 September during the UN General Assembly’s general debate. Earlier that month, the world’s two largest emitters, China and the United States, joined the Agreement.

The Agreement will now enter into force in time for the Climate Conference (COP 22) in Morocco in November, where countries will convene the first Meeting of the Parties to the Agreement. Countries that have not yet joined may participate as observers.

Rabi Island, Fiji. Rising sea levels and more extreme weather events pose an imminent threat to low-lying atoll islands across the Pacific. Photo: OCHA/Danielle Parry

Patricia Espinosa, the Executive Secretary of the UNFCCC, said: “Above all, entry into force bodes well for the urgent, accelerated implementation of climate action that is now needed to realize a better, more secure world and to support also the realization of the Sustainable Development Goals.”

“It also brings a renewed urgency to the many issues governments are advancing to ensure full implementation of the Agreement,” she added. “This includes development of a rule book to operationalize the agreement and how international cooperation and much bigger flows of finance can speed up and scale up national climate action plans.” she added.

In an earlier statement, Mr. Ban highlighted that strong international support for the Paris Agreement entering into force is “testament to the urgency for action, and reflects the consensus of governments that robust global cooperation is essential to meet the climate challenge.”

He pointed out that over the past decade, he has worked ceaselessly to bring countries together to accelerate the global response to climate change. During that time, he said he has visited communities on the climate frontlines, from the Arctic to the Amazon, and has witnessed how climate impacts are already devastating lives, livelihoods and prospects for a better future.

“I urge all governments and all sectors of society to implement the Paris Agreement in full and to take urgent action to reduce greenhouse gas emissions, strengthen climate resilience, and support the most vulnerable in adapting to inevitable climate impacts,” Mr. Ban said.

Congratulating all of the signatories of the Agreement, the Secretary-General encouraged all countries to accelerate their domestic processes to ratify the Agreement as soon as possible.

Specifically, the Agreement calls on countries to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low-carbon future, and to adapt to the increasing impacts of climate change.

It also aims to strengthen the ability of countries to deal with the impacts of climate change. The Agreement calls for appropriate financial flows, a new technology framework and an enhanced capacity-building framework to support action by developing countries and the most vulnerable countries in line with their own national objectives.

Enhanced transparency of action and support through a more robust transparency framework, are also among the key aims.