The condition for the climate deal going into force was having 55 countries representing 55% of the world’s greenhouse gas emissions have ratify it. After the US and China accepted the deal, 60 countries representing 47.7% of global greenhouse gas emissions had signed on. Since the EU represents about 12% of global emissions their entry will undoubtedly push the deal into effect.
India, which is responsible for 4.1% of emissions, also formally adopted the Paris agreement on Oct. 2.
The deal will be enacted 30 days after its ratification requirements have been met. The first meeting of the parties to the agreement, the CMA, will take place during the next annual United Nations climate conference, scheduled November 7, 2016.
Under the agreement, countries will be expected to act individually to keep average global temperatures from rising more than 2 degrees Celsius above preindustrial levels. Since a legally binding resolution would have required ratification by the Senate, which the Obama administration acknowledged was unlikely, no country can be forced to adhere to the deal. However, it does require countries to release targets and report emissions as a means to shame nations into compliance.
Once the agreement enters into force this year, the U.S. is prevented from pulling out for 4 years.