Whatever happens, the country will have lost credibility in climate protection, Oppenheimer says. "The United States can`t just step in and pretend it`s all back to 2015," he says. "It`s going to have to work to regain trust." The Paris Agreement is the first legally binding universal global agreement on climate change adopted at the Paris Climate Change Conference (COP21) in December 2015. 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.  "Green energy is not yet a substitute for fossil fuels – it is only expanding it," says Timothy Lenton, a climatologist at the University of Exeter in the UNITED Kingdom. The goal of the agreement is to reduce the global warming described in Article 2 and to improve the implementation of the UNFCCC through the People`s Climate March in New York.
More than 400,000 people – including a large WWF delegation – are showing that governments must act urgently to combat climate change, two days before world leaders gather in the city for a UN-led summit on the issue. 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. It`s worrying. Taking action to combat climate change is now economically viable. The longer you delay, the more you pay. We can promote economic growth, eradicate extreme poverty and improve people`s health and well-being by acting today. Although the United States played an important role in the development of the climate agreement, it will be the only one of the 200 parties to withdraw from the pact. 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.
 Historic Paris Agreement adopted. In the first truly global agreement on climate change mitigation, 195 countries approve a plan to prevent global temperatures from exceeding historic levels by more than 1.5 degrees Celsius.