On November 2, the Intergovernmental Panel on Climate Change (IPCC) met in Copenhagen to finalize the Synthesis Report, the last stage of its Fifth Assessment Report (AR5), which provides policymakers with a comprehensive assessment of the risks of climate change. The report completes the Fifth Assessment Report, the most comprehensive assessment of climate change yet undertaken. The first three volumes were released over the past fourteen months: The Physical Science Basis in September 2013, Impacts, Adaptation and Vulnerability, in March 2014 and Mitigation of Climate Change in April 2014.

The Synthesis Report confirms that climate change is being registered around the world and expresses with greater certainty than in previous assessments the fact that emissions of greenhouse gases and other anthropogenic drivers have been the dominant cause of observed warming since the mid-20th century. If no action is taken, the impacts on people and ecosystems will be widespread and irreversible. However, the implementation of stringent mitigations activities can ensure that the impacts of climate change remain within a manageable range, while options are available to adapt to the effects of climate change.

As Rajendra K. Pachauri, Chair of the IPCC, said in his address, little time is left before the window of opportunity to stay within 2°C of warming closes. To keep a good chance of staying below 2°C, and at manageable costs, emissions should drop by 40 to 70 percent globally between 2010 and 2050, falling to zero or below by 2100.

The report is available for download on the IPPC website