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. Faced with this setback, the world has united to bring the Kyoto Protocol to life. The other parties ensured that the Marrakesh agreements (a “set of rules” for the protocol) allayed the remaining concerns of Canada, Russia, Australia and Japan-countries needed to reach the ratification threshold. With these countries on board, the protocol could come into force in law. Exceptional efforts have been made to achieve this, including the smoothing of Russia`s accession to the World Trade Organization. On June 1, 2017, U.S. President Donald Trump announced that the United States would end all participation in the 2015 Paris Climate Change Agreement and begin negotiations to reintroduce the agreement “on a level playing field for the United States, its businesses, its workers, their people, its taxpayers” or form a new agreement.
 In withdrawing from the agreement, Trump said that “the Paris agreement will hurt the U.S. economy” and “permanently penalize the United States.”   Trump stated that the withdrawal would be consistent with his America First policy. The last time there was a major climate treaty, the United States was left out. Although Vice President Gore signed the Kyoto Protocol on behalf of the United States, the next administration of President George W. Bush withdrew his signature and refused to send it to Congress to consider ratification. Instead, Congress passed the byrd hail amendment, which provides that any future American participation in climate change agreements is accompanied by equivalent commitments from developing countries. It is rare that there is a consensus among almost all nations on a single subject. But with the Paris agreement, world leaders agreed that climate change was driven by human behaviour, that it was a threat to the environment and to humanity as a whole, and that global action was needed to stop it.