New Zealand signs historic climate deal

A total of 175 countries, including India, on Friday signed the Paris climate agreement at the United Nations, a record for a one-day signing of an worldwide accord, the United Nations said.

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

"China will finalize domestic legal procedures on its accession before the G20 Hangzhou summit in September this year", China's Vice Premier Zhang Gaoli told the United Nations signing ceremony, attended by some 55 heads of state and government.

The actor, who this year won his first Oscar for his portrayal of a frontiersman in "The Revenant", spoke in his role as UN Secretary-General Ban Ki-moon's "messenger of peace with a special focus on climate change".

"Walking away from the agreement would instantly turn the USA from a leader to a defector" with serious diplomatic consequences, Elliot Diringer of the US-based Center for Climate and Energy Solutions think tank told reporters on Thursday. The landmark deal takes a key step toward entering into force years ahead of schedule.

The climate ceremony brought together a wide range of states that on other issues might sharply disagree.

North Korea's Foreign Minister Ri Su Yong made a rare United Nations appearance to sign and Zimbabwe's President Robert Mugabe brought applause when he declared, "Life itself is at stake in this combat".

Countries that have not yet indicated they would sign the agreement Friday include some of the world's largest oil producers, including Saudi Arabia, Iraq, Nigeria and Kazakhstan, the World Resources Institute said.

"The 1.5-degree Celsius limit is a significantly safer defense line against the worst impacts of a changing climate", the United Nations stated.

The agreement requires countries to set a target for reducing their emissions, and to report back every five years, starting from 2020.

Many states still need a parliamentary vote to formally approve the agreement. Scientific analyses show the initial set of targets that countries pledged before Paris don't match the agreement's long-term goal to keep global warming below 2 degrees Celsius (3.6 degrees Fahrenheit), compared with pre-industrial times.

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 worldwide covenant.

The first three months of 2016 have broken temperature records and 2015 was the planet's warmest year since records began in the 19th century, with heat waves, droughts and rising sea levels. A separate analysis by Climate Action Tracker, a European group, projected warming of 2.7 degrees C. "The hardest work starts now".

As the Paris Agreement moves forward, there is some good news. "After 21 years of debates and conferences, it is time to declare no more talk, no more excuses, no more ten-year studies, no more allowing the fossil fuel companies to manipulate and dictate the science and policies that affect our future". States that didn't sign Friday have a year to do so.