The language of the agreement was negotiated by representatives of 197 parties at the 21st UNFCCC Conference of the Parties in Paris and agreed on 12 December 2015.   The agreement was signed at UN Headquarters in New York from 22 April 2016 to 21 April 2017 by states and regional economic integration organisations parties to the UNFCCC (convention).  The agreement stated that it would only enter into force if 55 countries that produce at least 55% of global greenhouse gas emissions (according to a list drawn up in 2015) ratify, accept, approve or adhere to the agreement.  On April 1, 2016, the United States and China, which together account for nearly 40% of global emissions, issued a joint statement confirming that the two countries would sign the Paris Climate Agreement.  175 contracting parties (174 states and the European Union) signed the agreement on the first day of its signing.   On the same day, more than 20 countries announced plans to join the accession as soon as possible in 2016. The ratification by the European Union has achieved a sufficient number of contracting parties to enter into force on 4 November 2016. The Paris Agreement is an agreement within the framework of the United Nations Framework Convention on Climate Change (UNFCCC) that deals with the reduction, adaptation and financing of greenhouse gas emissions from 2020. The agreement aims to address the threat of global climate change by keeping global temperatures well below 2 degrees Celsius above pre-industrial levels this century and to continue efforts to further limit the temperature increase to 1.5 degrees Celsius.  On November 4, 2019, the United States informed the custodian of its withdrawal from the agreement, which was to take effect exactly one year after that date.
 «You have managed to get an ambitious agreement, a binding agreement, a universal agreement. I will never be able to express more gratitude at a conference. You can be proud to be in front of your children and grandchildren. On June 1, 2017, U.S. President Donald Trump announced that the United States would withdraw from the agreement.  Under Article 28, the effective withdrawal date of the United States is the fastest possible date, given that the agreement entered into force in the United States on November 4, 2016. If it had decided to withdraw from the UNFCCC, it could be informed immediately (the UNFCCC came into force in 1994 for the United States) and come into force a year later. 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 has a legal right to do so.  The formal declaration of resignation could only be submitted after three years of implementation of the agreement for the United States in 2019.   The Paris Agreement came into force in November 2016. This is the first global agreement that commits all countries to more ambitious targets for reducing greenhouse gas emissions.
Norway was one of the first countries to ratify the agreement. The Paris Agreement gives reason to hope that countries around the world can work together to prevent dangerous climate change.