World leaders agreed in December to adopt plans to address planet-warming emissions, an attempt to slow the catastrophic effects of climate change. But signatories still needed to go back to their countries and ratify the deal a necessary step that was achieved on Wednesday.

The agreement , which seeks to limit global temperature rise to no more than 2 degrees Celsius (3.6 degrees Fahrenheit), couldnt take effect until at least 55 countries responsible for more than 55 percent of global greenhouse emissions formally adopted it. The European Unions ratification on Tuesday bumped up participation to the necessary threshold. By Wednesday, 73 countries had ratified the agreement, accounting for nearly 57 percent of emissions.

The climate deal will enter into force in 30 days less than a year after it was first reached. This is a major improvement over its predecessor, the Kyoto Protocol , which took effect eight years after it was adopted. That agreement didnt live up to its promise, however, as the United States never ratified it and it didnt include major emerging emitters like China and India.

More than 190 countries, representing 96 percent of global emissions, attended last years climate conference in Paris, part of the United Nations Framework Convention on Climate Change. The U.S. and China, the worlds two largest economies and greenhouse gas emitters, formally joined the agreement Sept. 3, encouraging other countries to do the same. India joined later in the month.

U.N. member countries and environmental advocates celebrated the victory this week.

This is a welcome development after years of frustratingly slow progress around the international climate talks, Andrew Steer, president and CEO of the World Resources Institute, said in a statement. In a remarkable display of global cooperation, countries joined hands, demonstrating that they understand the urgent need to accelerate action on climate change.

U.N. Secretary General Ban Ki-moon attended the European Parliament session on the Paris agreement Tuesday.

It is truly an honor to be able to witness the historic moment, he said during a press conference after the vote.

President Barack Obama praised the Paris agreement in an address Wednesday afternoon.

History may well judge it as a turning point for our planet, Obama said.

The Paris agreement alone will not solve the climate crisis, he added, noting that the work will be easier if countries continue to work together.

The deals earlier-than-anticipated approval is also a relief for supporters who are concerned about the agreements future under a potential Donald Trump presidency. The Republican nominee has expressed his opposition to the agreement on many occasions , even proposing that he would cancel it all together.

Although a President Trump could disregard the emissions-reduction goals the Obama administration pledged on behalf of the United States, legal experts say he likely would not be able to formally withdraw from or alter the climate deal for another four years or just as his first term would be wrapping up. This could make the deal Trump-proof, as the climate news and science site Climate Central put it last month .