COP20 requires all countries to clearly, transparently and understandably describe the contributions they intend to make to the 2015 agreement. The agreement states that each country`s efforts “will be an increase over time” and will reflect its “highest possible ambitions.” For developed countries, these should be absolute economic emissions targets, while developing countries will be encouraged to move towards this type of goal over time. The division between developed and developing countries is now more fluid than before the agreement. The Paris Agreement was launched at the signing on April 22, 2016 (Earth Day) at a ceremony in New York.  After the agreement was ratified by several EU member states in October 2016, there were enough countries that had ratified the agreement to produce enough greenhouse gases in the world for the agreement to enter into force.  The agreement came into force on November 4, 2016.  One hundred and sixteen countries agree with what experts call the world`s largest climate agreement in history, the Paris Agreement. Unlike previous agreements, almost all countries – developed and developing – must set emission reduction targets. However, countries can choose their own objectives and there is no implementation mechanism to ensure that they meet these objectives. As part of the agreement, countries must present objectives known as national contributions. The Paris Agreement, which will come into force in November 2016, aims to keep global temperature rise below 2 degrees Celsius and to strive to keep it below 1.5 degrees Celsius. However, analysts are calling for more action to achieve this goal. In 2017, President Donald J.
Trump withdrew the United States from the agreement and declared that he was imposing “draconian financial and economic burdens on the country.” The agreement stated that it would only enter into force (and therefore fully effective) if 55 countries that produce at least 55% of global greenhouse gas emissions (according to a list drawn up in 2015)  ratify, accept, approve or adhere to the agreement.   On April 1, 2016, the United States and China, which together account for nearly 40% of global emissions, issued a joint statement confirming that the two countries would sign the Paris climate agreement.  175 contracting parties (174 states and the European Union) signed the agreement on the first day of its signing.   On the same day, more than 20 countries announced plans to join the accession as soon as possible in 2016. The ratification by the European Union has achieved a sufficient number of contracting parties to enter into force on 4 November 2016. 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.  These rules of transparency and accountability are similar to those in other international agreements. Although the system does not include financial sanctions, the requirements are intended to easily monitor the progress of individual nations and promote a sense of overall group pressure, discouraging any towing of feet among countries that might consider it.