[Given recent interest in previous comparisons of CMIP5 simulations and observations of global mean surface air temperature, this is now a permanent page which will be incrementally updated as more data accumulates]
The figure below shows a comparison of CMIP5 simulations & observations of global mean surface air temperature, using a 1986-2005 reference period, and is an updated version of Figure 11.25 from IPCC AR5. The HadCRUT4 observations are shown in black with their 5-95% uncertainty in red. The Cowtan & Way v2.0 global temperature fills the gaps in the HadCRUT4 data and is shown in blue.
The grey shading shows the CMIP5 5-95% range for historical (pre-2005) & all future forcing pathways (RCPs, post-2005); the grey lines show the min-max range. The red hatching indicates the IPCC AR5 assessed likely (>66%) range for the 2016-2035 period. The UK Met Office forecast for 2014 is shown by the green error bar.
Notes: (1) Post-2005, the RCP forcings are used in the simulations rather than observational estimates of the forcing. (2) Whether the recent observations are inside or outside the 5-95% CMIP5 range is strongly dependent on the reference period chosen. (3) As the HadCRUT4 dataset has gaps over the Arctic it is likely to be a slight underestimate of the true recent global temperature anomaly, as the Cowtan & Way infilling technique suggests. (4) In this figure, the CMIP5 simulations are NOT masked to the HadCRUT4 observational coverage, unlike some previous examples on this blog.
31st January 2014: Added “Note (4)” about masking.
30th January 2014: Added “Note (3)” about missing data in the Arctic.
27th January 2014: Page created.