UNITED NATIONS， April 22， 2016 (Xinhua) -- United Nations Secretary-General Ban Ki-moon(C) declares the conclusion of the High-Level Event for the Signature of the Paris Agreement， at the UN headquarters in New York， April 22， 2016. (Xinhua/Li Muzi)
by Xinhua Writers Kong Xiaohan， Shi Xiaomeng
UNITED NATIONS， April 22 (Xinhua) -- In an extraordinary show of support for the global climate change campaign， 175 countries on Friday -- the first day the Paris Agreement was open for signature -- signed the historic agreement， heralding a promising start of the pact.
This is the largest one-day signing of any international agreement. The previous record was 119 countries signing the UN Convention on the Law of the Sea in 1982.
UN Secretary-General Ban Ki-moon was heartened. "This is a very moving day for me personally. I am touched to see so much support and political momentum to move the agreement forward."
Adopted by 196 parties last year in Paris， the pact sets a target of holding the global average rise in temperature below 2 degrees Celsius above pre-industrial levels， and preferably below 1.5 degrees Celsius.
The record number of signature countries also sends a powerful signal that these countries really do want to see the agreement reached in Paris actually happen， said David Nabarro， special adviser on the 2030 Agenda for Sustainable Development.
The great momentum seen at the UN headquarters on Friday could mean that the historic agreement will become effective long before the original 2020 deadline.
After the signing， the Paris Agreement needs 55 nations that together account for 55 percent of global greenhouse gas emissions to ratify before it can enter into force.
"The world will have met the requirement needed for the Paris Agreement to enter into force if all 175 countries that have signed today take the next step at the national level and join the agreement，" said Ban.
Also on Friday， 15 countries submitted ratification after their signing， including many small island developing countries.
These countries are "on the front line of climate impacts and they see the full implementation of the Paris Agreement as critical to their national survival and future，" said Ban.
Several countries， including Argentina， Australia， Cameroon， Canada， China， France， Mali， Mexico， the Philippines and the United States， announced plans to ratify the agreement within 2016.
Other parties， including Brazil， the European Union and Russia， also pledged speedy ratification without giving specific dates.
The secretary-general said the spirit of multilateralism is strong. The participation by so many countries on Friday， and the attendance by 55 world leaders， along with leaders from civil society and the private sector， leaves no doubt that the world is determined to take climate action， he added.
French President Francois Hollande， who hosted the Paris climate conference in 2015， said his country would take the lead to set a price on carbon dioxide.
United Nations Global Compact Executive Director Lise Kingo called on companies around the world to set an internal carbon price at a minimum of 100 U.S. dollars per metric ton over time.
"The Paris Agreement sends a clear signal that business and investors must put climate at the heart of decision-making，" said Kingo.
"We believe that setting a 100-U.S. dollar internal price on carbon is one of the most effective ways to drive climate deep into corporate strategy and investment. While leading companies have taken steps to price carbon， we need to see an ascent in ambition and price across the board，" she noted.
Christiana Figueres， executive secretary of the UN Framework Convention on Climate Change， said: "Today is a remarkable， record-breaking day in the history of international cooperation on climate change and a sustainable future for billions of people alive today and those to come."
"The urgency now is to implement the Paris Agreement's visionary pathways at a speed and scale that can deliver the next crucial steps， namely a swift peaking of global emissions， a climate neutral world in the second half of the century and the building of resilient countries and communities for every man， woman and child."
The Paris Agreement marked a watershed moment in global climate negotiations， especially after a failed climate summit in Copenhagen， Denmark， in 2009 and chronic disputes among countries on respective responsibilities.