Iran, Iraq and Libya – all members of the Organization of Petroleum Exporting Countries (Opec) – and conflict-torn states such as Yemen and South Sudan have not ratified the 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.  On June 1, 2017, U.S. President Donald Trump announced that the United States would withdraw from the agreement.  Under Article 28, the effective withdrawal date of the United States is the fastest possible date, given that the agreement entered into force in the United States on November 4, 2016. If it had decided to withdraw from the UNFCCC, it could be informed immediately (the UNFCCC came into force in 1994 for the United States) and come into force a year later.
On August 4, 2017, the Trump administration officially announced to the United Nations that the United States intends to withdraw from the Paris Agreement as soon as it has a legal right to do so.  The formal declaration of resignation could only be submitted after three years of implementation of the agreement for the United States in 2019.   Countries are also working to reach “the global peak in greenhouse gas emissions” as soon as possible. The agreement has been described as an incentive and engine for the sale of fossil fuels.   Adaptation – the steps to deal with the effects of climate change – is much more important under the Paris Agreement than it used to be under the UNFCCC. As well as the parties will make contributions to the reduction, the Agreement requires all parties to plan and implement adjustment efforts “where appropriate” and encourages all parties to report on their adjustment efforts and/or needs. The agreement also provides for a review of progress in adaptation and the adequacy and effectiveness of adjustment support in the overall inventory that will be completed every five years. Angola was the last country to ratify the climate agreement on 12 August 2020. Kyrgyzstan ratified on 18 February and Lebanon on 5 February. Under U.S.
law, a president may, in certain circumstances, authorize U.S. participation in an international agreement without submitting it to Congress. Whether the new agreement implements a prior agreement, such as the UNFCCC, ratified by the Council and Senate approval, and whether it is compatible with the existing United States and can be implemented on the basis of the existence of the United States.