On August 4, 2017, the Trump administration issued an official notice to the United Nations that the United States intended to withdraw from the Paris Agreement as soon as it was legally authorized to do so.  The call for withdrawal could only be submitted after the agreement for the United States was in force for 3 years on November 4, 2019.   On November 4, 2019, the U.S. government deposited the notice of withdrawal with the Secretary-General of the United Nations, depositary of the agreement, and formally withdrew from the Paris Climate Agreement a year later, when the withdrawal took effect.  After the November 2020 election, President-elect Joe Biden promised to reintroduce the United States into the Paris Agreement by his first day in office and renew America`s commitment to mitigating climate change.   These three objectives provide a single and clear direction for state and non-state actors in the long term, given the link between economic activity, greenhouse gas emissions and the effects of climate change. According to the latest available evidence, to meet the long-term temperature target, global greenhouse gas emissions would have to peak by 2020 and then be reduced to zero before the end of the century. In order to limit warming to 1.5°C, this reduction to zero must take place around 2050. Instead of giving China and India a passport to pollution, as Trump claims, the pact represents the first time these two major developing countries have agreed on concrete and ambitious climate commitments. Both countries, which are already ready to leave the world ahead in renewable energy, have made significant progress towards achieving their Paris goals. And since Trump announced his intention to withdraw the United States from the deal, the leaders of China and India have reaffirmed their commitment and continued to implement domestic measures to achieve their goals. Among other things, countries must report on their greenhouse gas inventories and progress towards their targets so that external experts can assess their success.
Countries should also reconsider their commitments by 2020 and present new targets every five years, with the aim of further reducing emissions. They must participate in a “global stocktaking” to measure collective efforts to achieve the long-term goals of the Paris Agreement. In the meantime, developed countries must also estimate the amount of financial assistance they will provide to developing countries to help them reduce their emissions and adapt to the effects of climate change. The Paris Agreement was opened for signature on 22 April 2016 (Earth Day) at a ceremony in New York.  After several European Union states ratified the agreement in October 2016, enough countries that had ratified the agreement were producing enough greenhouse gases worldwide for the agreement to enter into force.  The agreement entered into force on November 4, 2016.  National communication reports are often several hundred pages long and cover the measures taken by a country to reduce greenhouse gas emissions, as well as a description of its vulnerabilities and the impacts of climate change.  National communications are prepared in accordance with guidelines agreed by the Conference of the Parties to the UNFCCC. .