The Paris Agreement has an “upward” structure unlike most international environmental treaties, which are “top down”, characterized by internationally defined standards and objectives that states must implement.  Unlike its predecessor, the Kyoto Protocol, which sets legal commitment targets, the Paris Agreement, which focuses on consensual training, allows for voluntary and national objectives.  Specific climate targets are therefore politically promoted and not legally binding. Only the processes governing reporting and revision of these objectives are imposed by international law. This structure is particularly noteworthy for the United States – in the absence of legal mitigation or funding objectives, the agreement is seen as an “executive agreement, not a treaty.” Since the 1992 UNFCCC treaty was approved by the Senate, this new agreement does not require further legislation from Congress for it to enter into force.  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 Paris Agreement was launched at the signing on April 22, 2016 (Earth Day) at a ceremony in New York.
 After the agreement was ratified by several EU member states in October 2016, there were enough countries that had ratified the agreement to produce enough greenhouse gases in the world for the agreement to enter into force.  The agreement came into force on November 4, 2016.  While mitigation and adjustment require increased climate funding, adjustment has generally received less support and has mobilized less private sector action.  A 2014 OECD report showed that in 2014, only 16% of the world`s financial resources were devoted to adaptation to climate change.  The Paris Agreement called for a balance between climate finance between adaptation and mitigation, highlighting in particular the need to strengthen support for adaptation from the parties most affected by climate change, including least developed countries and small island developing states. The agreement also reminds the parties of the importance of public subsidies, as adjustment measures receive less public sector investment.  John Kerry, as Secretary of State, announced that the United States would double its grant-based adjustment funding by 2020.  The NDC partnership was launched at COP22 in Marrakech to improve cooperation so that countries have access to the technical knowledge and financial assistance they need to achieve major climate and sustainable development goals. The NDC partnership is led by a steering committee made up of industrialized and developing countries and international institutions and is supported by a support unit organized by the World Resources Institute and based in Washington, D.C. and Bonn, Germany. The NDC partnership is co-chaired by the governments of Costa Rica and the Netherlands and has 93 Member States, 21 institutional partners and 10 associate members.
It is rare that there is a consensus among almost all nations on a single subject. But with the Paris agreement, world leaders agreed that climate change is driven by human behaviour, that it poses a threat to the environment and to humanity as a whole, and that global action is needed.