UN Secretary General Ban Ki-moon has announced November 4 as the day the Paris Agreement to combat climate change became international law.
"Today we make history in humankind's effort to combat climate change. The landmark Paris Agreement on climate change has entered into force," Ban said at the UN headquarters in New York on Friday.
Article 21, paragraph 1, of the Paris Agreement states that the international climate deal will enter into force 30 days after the date on which at least 55 countries, accounting for 55 percent of the total global greenhouse gas emissions, have deposited their instruments of ratification, acceptance or approval with the UN secretary general.
Ban announced on October 5 that the conditions for the entry into force of the Paris Agreement had been met when a total of 73 countries including the world’s largest emitters China, the United States, and the European Union joined the pact.
A previously anticipated timeframe was given as 2020 but ratification was swift compared to other international treaties, showing strong international support. However, about 100 countries have yet to agree and much work needs to be done on the fine details of the pact to ensure it is not watered down.
"Our challenge is to sustain the momentum that has propelled the agreement into force. We remain in a race against time. But with … the 2030 agenda for sustainable development, the world has the plans we need to make the shift to a lower emission, climate resilient path," Ban said.
The Paris Agreement seeks to wean the world economy off fossil fuels in the second half of the century, limiting the rise in average world temperatures to "well below" 2.0 degrees Celsius (3.6 Fahrenheit) above pre-industrial times.
A report by the UN Environment Program released on Thursday said annual emissions must be kept below 42 billion tons of CO2 (carbon dioxide) by 2030 for the world to have a chance to meet the goals set out in the Paris Agreement.
Even if emission-cutting pledges under the Paris Agreement are fully implemented, the predicted 2030 emissions could put the world on track for a temperature rise of 2.9 to 3.4 degrees Celsius this century, the report said.
The next round of UN climate talks is scheduled on November 7 in Marrakesh, Morocco.