Against a backdrop of troubling news from the planet — including a scientific upgrade of expectations for sea level rise because of faster melting of Antarctica — the U.S. and China on Thursday pledged to jump-start their climate action plans.

The world’s two largest emitters issued a joint statement saying that they will sign the Paris climate agreement, negotiated late last year to put the world on a path to lowering greenhouse gas pollution, on April 22, the date of a long planned signing ceremony and the first day that countries can sign. April 22 is also Earth Day.

Our two countries, with this joint statement, are making an important step forward in building on the success of Paris by urging and encouraging swift entry into force of that agreement.”

The U.S. and China further said they would “take their respective domestic steps in order to join the Agreement as early as possible this year” and called on other countries to do likewise, “with a view to bringing the Paris Agreement into force as early as possible.”

“Our two countries, with this joint statement, are making an important step forward in building on the success of Paris by urging and encouraging swift entry into force of that agreement,” said Brian Deese, senior adviser to the President, on a press call.