Negotiators of the agreement stated that the INDCs presented at the time of the Paris conference were insufficient and found that «the estimates of aggregate greenhouse gas emissions in 2025 and 2030 resulting from the planned contributions at the national level are not covered by the least expensive scenarios of 2oC, but lead to a projected level of 55 gigatons in 2030.» and acknowledges that «much greater efforts to reduce emissions will be needed to keep the global average temperature increase to less than 2 degrees Celsius, reducing emissions to 40 gigatonnes or 1.5 degrees Celsius.»  [Clarification needed] At the 2011 Unfeding Climate Change Conference, the Durban Platform (and the ad hoc working group on the Durban Platform for Enhanced Action) was created to negotiate a legal instrument to mitigate climate change from 2020. The resulting agreement is expected to be adopted in 2015.  On August 4, 2017, the Trump administration formally communicated to the United Nations that the United States intends to withdraw from the Paris Agreement as soon as it is legally entitled to do so.  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.   The EU and its Member States are among the nearly 190 parties to the Paris Agreement.
The EU formally ratified the agreement on 5 October 2016, allowing it to enter into force on 4 November 2016. In order for the agreement to enter into force, at least 55 countries representing at least 55% of global emissions had to file their ratification instruments.