Story highlights The deal will go into effect in 30 days

"This gives us the best possible shot to save the one planet we've got," Obama said.

Washington (CNN) President Barack Obama held up the formal ratification of a climate agreement on Wednesday as a sign that influential countries of the world -- and particularly, the United States and China -- are serious about cooperating in order to reduce emissions.

Speaking formally from the Rose Garden, Obama touted the Paris Agreement, which was struck last year and creates a legally binding agreement to fight climate change. Obama and Chinese President Xi Jinping submitted their countries' plans to the United Nations last month, which formally ratified the agreement. And since the European Union signed off on the accord this week, the deal is now set to go into effect in 30 days.

"Today, the world has officially crossed the threshold for the Paris Agreement to take effect. Today the world meets the moment," Obama said. "No nation, not even one as powerful as ours, can solve this challenge alone. All of us have to solve it together."

The United States and China are the world's largest carbon polluters, but the deal needed to be ratified by 55 nations that account for at least 55% of global greenhouse gas emissions. The agreement limits average global warming to 2 degrees Celsius above pre-industrial temperatures.

"This gives us the best possible shot to save the one planet we've got," Obama said.

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