By Paul Davies and Michael Green

The Paris Climate Agreement (Agreement) officially enters into force today, 30 days after it was ratified by at least 55 Parties to the Convention, representing at least an estimated 55% of the total global greenhouse gas emissions.

From today, the provisions within the Agreement will be legally binding upon, and enforceable against, the signatory states. In light of this, a number of interesting obligations have been triggered, namely: (i) national climate change plans have been transformed from Intended Nationally Determined Contributions to Nationally Determined Contributions; (ii) the governing body, the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement (CMA), must be established to preside over the implementation of the Agreement; and (iii) a rule book to govern the Agreement and prescribe rules for reporting and accounting for climate change action should be produced imminently.

For any country that joins after today, the Agreement will become legally binding 30 days after it deposits its instrument of ratification, acceptance, approval or accession with the Secretary-General.

The US and China ratified the Agreement in mid-September, giving substantial weight to the commitment outlined in the Agreement. With global powers (and leading emitters) backing the Agreement, the European Union followed soon after, officially ratifying the Agreement on 30 September 2016. The UK is yet to follow suit. However, Theresa May has suggested the UK Government will ratify the Agreement before the end of 2016.

While there remain a number of uncertainties in how and to what extent the Agreement will ultimately prove successful, the unprecedented speed of its ratification is an indication that mitigating climate change risk and reducing carbon emissions is considered a global priority by a number of governments.

This post was prepared with the assistance of Ashleigh Humphries in the London office of Latham & Watkins. 

Read more on the Paris Agreement:

US and China Ratify the Paris Climate Agreement

China One of First Countries to Sign Paris Agreement