President Obama was able to formally enshrine the United States in the agreement through executive measures because he did not impose new legal obligations on the country. The United States already has a number of instruments on the books, under laws already passed by Congress to reduce carbon pollution. The country officially joined the agreement in September 2016, after submitting its request for participation. The Paris Agreement was only able to enter into force after the formal accession of at least 55 nations representing at least 55% of global emissions. This happened on October 5, 2016 and the agreement came into force 30 days later, on November 4, 2016. Article 28 of the agreement allows the parties to terminate the contract following a notification of an appeal to the custodian. This notification can only take place three years after the agreement for the country comes into force. The payment is made one year after the transfer. Alternatively, the agreement provides that the withdrawal of the UNFCCC, under which the Paris Agreement was adopted, also withdraws the state from the Paris Agreement. The terms of the UNFCCC`s exit are the same as those of the Paris Agreement. There is no provision in the agreement for non-compliance. President Trump is pulling us out of the Paris climate agreement. 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.  A “national communication” is a kind of report from countries that have ratified the United Nations Framework Convention on Climate Change (UNFCCC).  Developed countries are required to submit national submissions every four years and developing countries should do so.    Some least developed countries have not submitted national communications in the past 5-15 years, mainly due to capacity constraints. Although the United States and Turkey are not parties to the agreement, as they have not indicated their intention to withdraw from the 1992 UNFCCC, they will continue to be required, as an “Annex 1″ country under the UNFCCC, to end national communications and establish an annual inventory of greenhouse gases.  According to the European Commission`s emissions database, the seven countries that have not yet ratified the agreement account for about 4% of global greenhouse gas emissions.
The United States, the second largest emitter after China, accounts for 13%. The countries most affected by the effects of climate change will be low-lying nations, particularly vulnerable to sea level rise, and developing countries that do not have the resources to adapt to changes in temperature and precipitation.