The Paris Agreement was launched at the signing on April 22, 2016 (Earth Day) at a ceremony in New York.  After the agreement was ratified by several EU member states in October 2016, there were enough countries that had ratified the agreement to produce enough greenhouse gases in the world for the agreement to enter into force.  The agreement came into force on November 4, 2016.  As explained in the C2ES exit letter, the Participation of the United States in the Paris Agreement can only be decided by the President, without, among other things, seeking the Council and the approval of the Senate, due to the development of an existing treaty, the United Nations Framework Convention on Climate Change. If Biden is president, he would have enough authority to join it as an “executive convention.” The NRDC is working to make the Global Climate Climate Action Summit a success by inspiring more ambitious commitments to the historic 2015 agreement and enhanced pollution reduction initiatives. On October 5, 2016, when the agreement reached enough signatures to cross the threshold, U.S. President Barack Obama said, “Even if we achieve all the goals… we will only get to part of where we need to go. He also said that “this agreement will help delay or avoid some of the worst consequences of climate change.” It will help other nations reduce their emissions over time and set bolder goals as technology progresses, all under a strong transparency system that will allow each nation to assess the progress of all other nations.   The level of NCC defined by each country will determine the objectives of that country. However, the “contributions” themselves are not binding under international law because of the lack of specificity, normative nature or language necessary to establish binding standards.
 In addition, there will be no mechanism to compel a country to set a target in its NDC on a specified date and not for an application if a defined target is not achieved in an NDC.   There will be only a “Name and Shame” system  or as UN Deputy Secretary General for Climate Change, J. Pésztor, CBS News (US), a “Name and Encouragement” plan.  Since the agreement has no consequences if countries do not live up to their commitments, such a consensus is fragile. A cattle of nations withdrawing from the agreement could trigger the withdrawal of other governments and lead to the total collapse of the agreement.  The Paris Agreement  is an agreement under the United Nations Framework Convention on Climate Change (UNFCCC) that deals with the reduction, adaptation and financing of greenhouse gas emissions and was signed in 2016. The language of the agreement was negotiated by representatives of 196 States Parties at the 21st UNFCCC Conference of parties held at Le Bourget, near Paris, France, and agreed on 12 December 2015.   Since February 2020, all 196 UNFCCC members have signed the agreement and 189 have left.  Of the seven countries that are not parties to the law, Iran and Turkey are the only major emitters. However, the parties could not agree on how to implement Article 6 of the Coal Market Agreement in the 24 or 25, and they deferred those decisions to COP 26. On August 4, 2017, the Trump administration officially announced to the United Nations that the United States intends to withdraw from the Paris Agreement as soon as it is legally entitled to it.
 The formal declaration of resignation could not be submitted until after the agreement for the United States came into force on November 4, 2019 for a three-year date.   On November 4, 2019, the U.S. government filed the withdrawal notice with the Secretary-General of the United Nations, custodian of the agreement, and formally withdrew from the Paris Agreement a year later, when the withdrawal came into effect.  After the November 2020 elections, President-elect Joe Biden promised to reinstate the United States in the Paris Agreement for his first day in office and renew the U.S. commitment to climate change mitigation.