NEW YORK: The signing ceremony for the Paris Agreement on climate change was held at the United Nations (UN) Headquarters in New York where leaders of over 175 countries, including Pakistan, signed the landmark agreement, giving a strong push to the international efforts against global warming.

 Federal Interior Minister Chaudhry Nisar Ali Khan signed the climate change agreement on the behalf of Pakistan.

 UN Secretary-General Ban Ki-moon hosted the signing ceremony.

 In an unprecedented display of unity and action in the 71-year history of the United Nations, world leaders and government representatives lined up in the UN General Assembly Hall to ink the historic document, setting a new record for day-one endorsement of any international covenant.

 "We are breaking records in this Chamber ... Today is a day for our children and grandchildren and all generations to come," said UN Secretary-General Ban Ki-moon before the start of the signing process, which lasted some 2.5 hours.

 Taking place on the UN-designated Earth Day, Friday's signing involved nearly 90 percent of all the existing countries on earth -- from major powers like the United States and China to small island states such as Fiji and Maldives.

 France was given the honor to sign the pact first, in recognization of its hosting of the UN climate change conference in Paris in December 2015, which gave birth to the pact after nearly two weeks of tough negotiations.

 Fifteen other countries were also among the first to sign as they had pledged to ratify the agreement immediately after the signing.

 The agreement can enter into force 30 days after at least 55 parties that account for at least 55 percent of global greenhouse gas emissions have ratified it.

 China became the 21st signatory as Vice Premier Zhang Gaoli, the special envoy of President Xi Jinping, announced the country would ratify the pact before the G20 Hangzhou summit in September.

 U.S. Secretary of State John Kerry, who signed the document with his two-year-old granddaughter Isabelle on his lap, said his country "looks forward to formally joining this agreement this year."

 The Paris accord aims to keep the global average rise in temperature below 2 degrees Celsius above pre-industrial levels through drastic emissions cuts.

 However, there remain quite a few obstacles for the achievement of this ambitious goal, particularly the divergence between developed and developing countries over thorny issues like funding, responsibility and technology transfer.

 "We are in a race against time," Ban warned while addressing the signing ceremony. The window for curbing global temperature rises is rapidly closing, he added.

 Scientists said the monthly global temperature record has kept being broken over the past 11 months, and that 2015 has become the planet's warmest year since the late 19th century.

 Addressing the ceremony as a youth representative, 16-year-old Getrude Clement from Tanzania said: "As young people, the future is ours, but this is not the future we want for ourselves”