Summary/Abstract
This commentary identifies why an IPCC Special Report on 1.5 °C should focus on resolving fundamental scientific and political uncertainties, not fixate on developing unachievable mitigation pathways. The commentary builds on key findings in the IPCC AR5, the United Nations Environment Programme (UNEP) Emissions Gap Report and the United Nations Framework Convention on Climate Change (UNFCCC) Intended Nationally Determined Contributions (INDC) Synthesis Report, to identify key scientific knowledge gaps on mitigation pathways that need to be addressed in the potential IPCC Special Report specifically requested by policy makers in Paris.