Chapter 12 of the 5th Assessment Report of IPCC (Intergovernmental Panel on Climate Change) deals with future projections of climate change in the long-term. Long-term in this case means beyond the middle of the 21st century when the projections start to depend more strongly on the pathway or scenario of emissions of greenhouse gases, principally CO2. We rely extensively on computer models of the climate system for this as, obviously, there are no observations of the future. While computer models are not completely accurate in their ability to project future climate change, it is possible to use our understanding of the climate system to assess uncertainties...