President Rodrigo Duterte has signed the Paris Agreement on Climate Change aimed at slashing greenhouse gases and keeping global temperature increases to "well below" 2 degrees Celsius.

In a statement, Climate Change Commissioner Manny de Guzman said he is overjoyed with the President’s ratification of the Paris Agreement.

"The Philippine delegation’s hard work to lobby the 1.5-degree climate goal during the Paris negotiations has finally paid off. This is a clear articulation of his marching orders for the Climate Change Commission in the succeeding months," he said.

"Not only does this affirm the President’s pronouncement during his first SONA that climate change is a top priority of this administration, but also his advocacy of championing climate justice for the poorest of our poor."

The signed pact will be submitted to the Senate today at 2 p.m.

In December 2015, nearly 200 countries -- including the Philippines under then-President Benigno Aquino III -- agreed on a binding global compact to slash greenhouse gases and keep global temperature increases to "well below" 2 degrees Celsius.

Manila promised to cut carbon emissions by 70 percent by year 2030, even if the country is not a major emitter.

Wealthy countries were also asked to set aside at least $100 billion yearly as financial assistance to developing countries to enable all countries to actualize renewable energy sources starting 2020.

Duterte earlier admitted that he still has misgivings about the Paris climate pact, saying the historic agreement is tilted in favor of industrialized nations.

"I have misgivings on the climate change pact, even former President Fidel Ramos criticized me for not signing the pact. It was a Cabinet decision. I said, 'Let's put it to a vote,'" he said.

In his statement, De Guzman said the 1.5-degree climate goal as prescribed in the Paris Agreement "is our threshold of chance and hope."

"I believe that our President’s resolve for climate action will keep us in the right direction of attaining social justice," he said.

He also commended Senator Loren Legarda, UN Global Champion for Resilience, for being passionate and constant in her commitment and advocacy to ratify the Paris Agreement.