The Paris Agreement has an “upward” structure unlike most international environmental treaties, which are “top down”, characterized by internationally defined standards and objectives that states must implement.  Unlike its predecessor, the Kyoto Protocol, which sets legal commitment targets, the Paris Agreement, which focuses on consensual training, allows for voluntary and national objectives.  Specific climate targets are therefore politically promoted and not legally binding. Only the processes governing reporting and revision of these objectives are imposed by international law. This structure is particularly noteworthy for the United States – in the absence of legal mitigation or funding objectives, the agreement is seen as an “executive agreement, not a treaty.” Since the 1992 UNFCCC treaty was approved by the Senate, this new agreement does not require further legislation from Congress for it to enter into force.  The negotiators of the agreement stated that the INDCs presented at the time of the Paris conference were insufficient and found that “the estimates of aggregate greenhouse gas emissions in 2025 and 2030, resulting from planned contributions at the national level, do not fall into scenarios at 2oC at the lowest cost, but lead to a projected level of 55 gigatonnes in 2030.” and acknowledges that “much greater efforts to reduce emissions will be needed to keep the global average temperature increase to less than 2 degrees Celsius, reducing emissions to 40 gigatonnes or 1.5 degrees Celsius.”  [Clarification needed] The agreement stated that it would only come into force (and therefore fully effective) if 55 countries responsible for at least 55% of global greenhouse gas emissions (according to a 2015 list) would ratify , approve, 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.