In 1992, President George H.W. Bush joined 107 other heads of state at the Rio Earth Summit in Brazil to adopt a series of environmental agreements, including the UNFCCC framework, which is still in force today. The international treaty aims to prevent dangerous human intervention in the planet`s climate systems in the long term. The pact does not set limits on greenhouse gas emissions from individual countries and does not contain enforcement mechanisms, but establishes a framework for international negotiations on future agreements or protocols to set binding emissions targets. Participating countries meet annually at a Conference of the Parties (COP) to assess their progress and continue discussions on how best to combat climate change. The Paris Agreement is an agreement within the framework of the United Nations Framework Convention on Climate Change (UNFCCC) that deals with the reduction, adaptation and financing of greenhouse gas emissions from 2020. The agreement aims to address the threat of global climate change by keeping global temperatures well below 2 degrees Celsius above pre-industrial levels this century and to continue efforts to further limit the temperature increase to 1.5 degrees Celsius.  The Paris Agreement contains a series of binding measures to monitor, verify and publicly report progress towards a country`s emission reduction targets. Improving transparency rules applies a common framework to all countries, providing housing and support to nations that are not currently able to strengthen their systems over time. In 1995, the contracting parties to the climate convention adopted texts with limited and non-binding effects, but which defined fundamental principles and objectives.
The Kyoto Protocol, adopted in 1997 and weakened by the non-ratification of the United States and the withdrawal of Canada, Russia, Japan and Australia, set specific binding targets, including figures for industrialized countries, without quantifying the commitment of developing countries. The Copenhagen conference (COP15) recognized the need to limit the temperature increase to 2oC above pre-industrial levels and called for an increase in the resources of industrialized countries. A preliminary inventory-impact study was published in Nature Communications in April 2020. Based on a public policy database and a multi-model scenario analysis, the authors showed that the implementation of current strategies by 2030 leaves an average emission gap of 22.4 to 28.2 GtCO2eq, with optimal means to achieve targets well below 2 degrees Celsius and 1.5 degrees Celsius. If national contributions were fully implemented, this gap would be reduced by one-third. The countries assessed did not achieve their promised contributions with implemented measures (implementation deficit) or experienced a gap in ambition with optimal paths to well below 2oC. The study showed that all countries should accelerate the implementation of renewable technology strategies, while improving efficiency in emerging and fossil fuel-dependent countries is particularly important.  The Paris Agreement marks the culmination of a positive dynamic that began in 2011 in Durban (COP17) and fosters innovative approaches inspired by the experience of different countries.