In 2016, several countries signed an agreement with the United Nations to reduce their greenhouse gas emissions by 2020. With less than six months to go until the Paris agreement comes into force, the Mexican government has not yet announced the strategy it will implement to join the global crusade against climate change. The EU and its member states are individually responsible for ratifying the Paris Agreement. There was a strong preference for the EU and its 28 Member States to simultaneously table their ratification instruments to ensure that neither the EU nor its Member States commit to obligations that belong exclusively to the other and there was concern that there was a disagreement over each Member State`s share of the EU-wide reduction target. just as Britain`s vote to leave the EU could delay the Paris pact.  However, on 4 October 2016, the European Parliament approved the ratification of the Paris Agreement and the EU tabled its ratification instruments on 5 October 2016 with several EU Member States.  The language of the agreement was negotiated by representatives of 197 parties at the 21st UNFCCC Conference of 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.