While 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.  Under the Paris Agreement, each country must define, plan and report regularly on its contribution to warming mitigation.  There is no mechanism for a country to set an emission target for a specified date, but any target should go beyond the previous targets. The United States formally withdrew from the agreement the day after the 2020 presidential election, although President-elect Joe Biden said America would return to the agreement after his inauguration.  In addition to the Kyoto Protocol (and its amendment) and the Paris Agreement, the parties to the convention agreed to other commitments at the conferences of the parties to the UNFCCC. These include the Bali Action Plan (2007),  the Copenhagen Agreement (2009),  on the Cancun Agreements (2010),  and the Durban Platform for Enhanced Action (2012).  The Paris Agreement  is an agreement under the United Nations Framework Convention on Climate Change (UNFCCC) that deals with the reduction, adaptation and financing of greenhouse gas emissions and was signed in 2016. The language of the agreement was negotiated by representatives of 196 States Parties at the 21st UNFCCC Conference of parties held at Le Bourget, near Paris, France, and agreed on 12 December 2015.   Since February 2020, all 196 UNFCCC members have signed the agreement and 189 have left.  Of the seven countries that are not parties to the law, Iran and Turkey are the only major emitters. Implementation of the agreement by all Member States will be evaluated every five years, with the first evaluation in 2023.
The result will be used as an input for new national contributions from Member States.  The inventory will not be national contributions/achievements, but a collective analysis of what has been achieved and what remains to be done. 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.