It started from the Kyoto Protocol of 1997 containing the commitments of industrialized countries to seek effective solutions to reduce emission of certain greenhouse gases, responsible for global warming.
This agreement, of course, is the result of a long work: the work of the UN for sustainable development already started in 2000 with the Millennium Declaration and the eight Millennium Development Goals continues, a project concluded in 2015 with good success on many fronts.
The main change, which denotes how this project is more ambitious, is that there are no differences in the goals set between developed and developing countries: the goals to be achieved are common, according to the philosophy that everyone must do their part to ferry all states towards this new model. Read more about the details of the agreement.