China and the United States announced the ratification of the Paris agreement to contrast climate change.

At the opening of the Group summit (G20) which took place on 3 and 4 September in Hangzhou, the US President, Barack Obama, and the President of China, Xi Jinping, have announced that they had sent their plan to reduce levels of greenhouse gas emissions in their respective countries to the Secretariat of the UN Convention on climate change, in this way has been officially ratified the Paris agreement by both Countries,

The long-awaited decision by the US and China is an important step forward for the entry into force of the Agreement of Paris, which - according to the rules of the UN Convention on Climate Change - takes place thirty days after the  ratification by at least 55 countries that together achieve minimum of 55% global emissions of greenhouse gases. China and the USA (respectively first and second largest emitter of greenhouse gases) together represent 39% of global emission. Before the declaration of the two super-powers, 23 countries had ratified the agreement, representing however, only 1% of global emissions.

This means that the agreement has a good chance of overcoming the limit 55/55 and become active before the end of the year. Now would be important the EU decision (collectively responsible for 12% of global greenhouse gas emissions) as a whole and the individual member countries. Currently no EU country has ratified the Agreement of Paris (https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XXVII-7-d&chapter=27&clang=_en ).

Last December, the EU unanimously approved the agreement in Paris and had assumed the formal commitment b to reduce 'jointly', by 2030, emissions of 28 EU Member Countries of 40% f the below the levels of 1990. Nevertheless  with the outcome of the referendum vote for Britain's exit from the EU it has opened  the complex issue of redefinition of effort-sharing among EU countries without Britain.