A new theme that has proved to be the centre of gravity of the Paris negotiations was born out of the fact that many of the worst effects of climate change will be too severe or will come too quickly to be avoided by adaptation measures. The Paris Agreement explicitly recognizes the need to repair such losses and damages and seeks to find appropriate responses.  It is specified that losses and damage can take different forms, both as immediate effects of extreme weather events and as slow effects, such as land loss at sea level for deep islands.  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.  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.   Niklas Huhne, a climatologist and founder of the New Climate Institute in Germany, said that Turkey was “tightening” the list of countries that do not yet need to ratify the agreement. The long-term objective of the Paris Agreement is to keep the increase in global average temperature well below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels; and to continue efforts to limit the increase to 1.5 degrees Celsius, while acknowledging that this would significantly reduce the risks and effects of climate change. This should require a rapid reduction in emissions to achieve “a balance between anthropogenic emissions from sources and the reduction of greenhouse gases from wells” in the second half of the 21st century.