While the expanded transparency framework is universal, as is the global stocktake that takes place every 5 years, the framework is designed to provide “built-in flexibility” to distinguish the capacities of developed and developing countries. With its ratification by the European Union, the agreement received enough contracting parties to enter into force on 4 November 2016. On June 1, 2017, U.S. President Donald Trump announced that the United States would withdraw from the agreement.  According to Article 28, the earliest possible effective withdrawal date for the United States is November 4, 2020, with the agreement having entered into force in the United States on November 4, 2016. If it had chosen to withdraw from the UNFCCC, it could be notified immediately (the UNFCCC entered into force for the United States in 1994) and enter into force a year later. The 4. In August 2017, the Trump administration sent an official notice to the United Nations stating that the United States intended to withdraw from the Paris Agreement as soon as it was legally allowed to do so.  The formal resignation could not be submitted until the agreement was in force for the United States for 3 years in 2019.   The Eiffel Tower in Paris, lit in green to celebrate the entry into force of the Paris Agreement, the most ambitious climate agreement in history, on November 4, 2016 (Photo: Jean-Baptiste Gurliat / Paris City Hall) In fact, research clearly shows that the costs of climate change inaction far outweigh the costs of reducing carbon pollution. A recent study suggests that if the United States fails to meet its Paris climate goals, it could cost the economy up to $6 trillion in the coming decades.
A global failure to meet the NDCs currently set out in the agreement could reduce global GDP by more than 25% by the end of the century. At the same time, another study estimates that meeting – or even exceeding – the Paris targets through infrastructure investments in clean energy and energy efficiency could have huge global benefits – around $19 trillion. Ultimately, the goal of the agreement is to keep the global average temperature rise below 2 degrees Celsius above pre-industrial levels. Joining the agreement means that countries are required to plan and report on their efforts to reduce global warming and emissions. At the 2011 United Nations Climate Change Conference, the Durban Platform (and the ad hoc working group on the Durban Platform for Enhanced Action) was established with the aim of negotiating a legal instrument for climate action from 2020 onwards. The resulting agreement is expected to be adopted in 2015.  INDCs become NDCs – Nationally Determined Contributions – as soon as a country formally accedes to the Agreement. There are no specific requirements on how countries should reduce their emissions or to what extent, but there have been political expectations regarding the nature and severity of the targets set by different countries. As a result, national plans vary considerably in scope and ambition, largely reflecting each country`s capacities, level of development and contribution to emissions over time. China, for example, has pledged to reduce its carbon emissions by 2030 at the latest and to reduce carbon emissions per unit of gross domestic product (GDP) by 60 to 65 percent by 2030 compared to 2005 levels. India has set a target of reducing emissions intensity by 33-35% from 2005 levels and producing 40% of its electricity from non-fossil fuels by 2030.
The implementation of the agreement by all member countries will be evaluated every 5 years, the first evaluation will take place in 2023. The result will serve as a contribution to new Nationally Determined Contributions by Member States.  The assessment is not a contribution/achievement of individual countries, but a collective analysis of what has been achieved and what still needs to be done. The Paris Agreement officially entered into force on 4 November 2016. Other countries continued to become parties to the Convention as they had completed their national approval procedures. To date, 195 Contracting Parties have signed the Convention and ratified 189. More information on the Paris Agreement and the status of ratification is available here. Under the Paris Agreement, each country must regularly identify, plan and report on its contribution to the fight against global warming.
 There is no mechanism requiring a country to set a specific emission target on a specific date, but each target should go beyond the targets set previously. The United States officially withdrew from the agreement the day after the 2020 presidential election, although President-elect Joe Biden said America would join the agreement after his inauguration.  The extent to which each country is on track to meet its commitments under the Paris Agreement can be continuously tracked online (via the Climate Action Tracker and the Climate Clock). The U.S. left in 2020, but on the first day of Joe Biden`s term, he signed an executive order to join the Paris Agreement. .