The Paris Agreement was launched at the signing on April 22, 2016 (Earth Day) at a ceremony in New York.  After the agreement was ratified by several EU member states in October 2016, there were enough countries that had ratified the agreement to produce enough greenhouse gases in the world for the agreement to enter into force.  The agreement came into force on November 4, 2016.  This high-level event was an opportunity for other countries to publicly commit to the Paris Agreement by the end of 2016. Yes, there is broad consensus within the scientific community, although some deny that climate change is a problem, including politicians in the United States. When negotiating teams meet for international climate talks, “there is less skepticism about science and more disagreement about how to set priorities,” said David Victor, professor of international relations at the University of California, San Diego. The basic science is that: The agreement contains commitments from all countries to reduce their emissions and cooperate to adapt to the effects of climate change, and calls on countries to strengthen their commitments over time. The agreement provides developed countries with a means to assist developing countries in their mitigation and adaptation efforts, while establishing a framework for monitoring and reporting transparently on developing countries` climate goals. If countries strengthen their commitments and the United States takes over the treaty, some experts hope that the Paris agreement could reduce emissions fairly quickly. They say it is promising that dozens of countries have pledged to pursue net zero emissions in the coming decades and increase their use of renewable energy. The European Union, Japan and South Korea, for example, are working to be climate neutral by 2050, while China has pledged to meet this target by 2060.
Another key difference between the Paris Agreement and the Kyoto Protocol is its scope. While the Kyoto Protocol distinguishes between Schedule 1 countries and those not annexed to Schedule 1, this branch is scrambled in the Paris Agreement, as all parties must submit emission reduction plans.  While the Paris Agreement continues to emphasize the principle of “common but differentiated responsibility and respective capabilities” – the recognition that different nations have different capacities and duties to combat climate change – it does not offer a specific separation between developed and developing countries.  It therefore appears that negotiators will have to continue to address this issue in future rounds of negotiations, although the debate on differentiation could take on a new dynamic.  “Progress will not be made around the world with all countries, but in small groups and by sector,” says Victor.