Unlike the Kyoto Protocol, which set legally binding emission reduction targets (as well as penalties for non-compliance) only for industrialized countries, the Paris Agreement requires all countries – rich, poor, developed and developing – to take their share and reduce their greenhouse gas emissions. To this end, the Paris Agreement provides for greater flexibility: commitments that countries should make are not included, countries can voluntarily set their emissions targets and countries will not be penalized if they do not meet their proposed targets. But what the Paris agreement requires is to monitor, report and reassess, over time, the objectives of individual and collective countries, in order to bring the world closer to the broader objectives of the agreement. And the agreement stipulates that countries must announce their next round of targets every five years, contrary to the Kyoto Protocol, which was aimed at this target but which contained no specific requirements to achieve this goal. In response to the climate challenge, the agreement recognizes that states have common but differentiated responsibilities, i.e. according to their national capabilities and specificities. 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. The Paris Agreement is the world`s first comprehensive climate agreement.  On August 4, 2017, the Trump administration formally communicated to the United Nations that the United States intends to withdraw from the Paris Agreement as soon as it is legally entitled to do so.
 The formal declaration of resignation could not be submitted until after the agreement for the United States came into force on November 4, 2019 for a three-year date.   On November 4, 2019, the U.S. government filed the withdrawal notice with the Secretary-General of the United Nations, custodian of the agreement, and formally withdrew from the Paris Agreement a year later, when the withdrawal came into effect.  After the November 2020 elections, President-elect Joe Biden promised to reinstate the United States in the Paris Agreement for his first day in office and renew the U.S. commitment to climate change mitigation.   In order to contribute to the objectives of the agreement, countries have submitted comprehensive national plans to combat climate change (nationally determined contributions, NDC). These are not yet sufficient to meet the agreed temperature targets, but the agreement points to the way forward for further measures. 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.  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.   Recognizing that many developing countries and small island developing states that have contributed the least to climate change are most likely to suffer the consequences, the Paris Agreement contains a plan for developed countries – and others that are able to do so – to continue to provide financial resources to help developing countries reduce and increase their resistance to climate change.