Climate Change 2014 Synthesis Report

This summary follows the structure of the longer AR5 Climate Change 2014 report, which addresses the following topics: observed changes and their causes; future climate change, risks and impacts; future pathways for adaptation, mitigation and sustainable development; and adaptation and mitigation. In this report, the certainty in key assessment findings is communicated as in the Working Group Reports and Special Reports. It is based on the author teams’ evaluations of underlying scientific understanding and is expressed as a qualitative level of confidence (from very low to very high) and, when possible, probabilistically with a quantified likelihood (from exceptionally unlikely to virtually certain). Where appropriate, findings are also formulated as statements of fact without using uncertainty qualifiers. This report includes information relevant to Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC).