The Kyoto Protocol, the international agreement that preceded the Paris agreement, was also “under” the UNFCCC, although its provisions were largely followed by those of the Paris Agreement. 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. 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.  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.   The Paris Agreement was adopted on 12 December 2015 at COP21 in Paris, France, by the Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC). The Vienna Convention on Treaty Law provides for the adoption of the formal act, the form and content of an agreement. In adopting the Paris Agreement, each of the contracting parties approved the text of the Paris Agreement.
This does not mean that the parties to the UNFCCC will automatically become parties to the Paris Agreement. At the 2011 UN Climate Change Conference, the Durban Platform (and the ad hoc working group on the Durban Platform for Enhanced Action) were created to negotiate a legal instrument to mitigate climate change from 2020. The resulting agreement is expected to be adopted in 2015.  Although the agreement has been welcomed by many, including French President Francois Hollande and UN Secretary-General Ban Ki-moon, criticism has also emerged. James Hansen, a former NASA scientist and climate change expert, expressed anger that most of the agreement is made up of “promises” or goals, not firm commitments.  He called the Paris talks a fraud with “nothing, only promises” and believed that only a generalized tax on CO2 emissions, which is not part of the Paris agreement, would force CO2 emissions down fast enough to avoid the worst effects of global warming.  The agreement commits all countries to reduce their emissions and cooperate to adapt to the effects of climate change and calls on countries to strengthen their commitments over time. The agreement provides developed countries with a means to assist developing countries in their mitigation and adaptation efforts, while establishing a framework for monitoring and reporting transparently on developing countries` climate goals.