Temperature projections are made for the IPCC fifth assessment report (AR5) scenarios, referred to as “Representative Concentration Pathways” (RCPs), using the MAGICC simple climate model.
These RCPs have been chosen to span climate outcomes rather than socioeconomic futures, but are found to closely match key mitigated and non-mitigated scenarios examined previously under AVOID. Consequently the temperature projections in this report and those in AR5 can usefully be interpreted in the context of mitigation or business as usual scenarios.
A preliminary comparison is also made of the simple model used in UKCP09 with some elements of the differences in approach to sampling uncertainty examined. While the models are broadly consistent, further work is required to fully quantify and understand the differences between the approaches.