Lord Monckton has written a guest post at WUWT. In this post he is showing graphs, which are meant to show atmospheric CO2 concentrations of the IPCC’s A2 scenario (AR4, fig. 10.26, p. 803) compared to NOAA’s global trend data.
In both graphics the slope of the “IPCC scenario” as depicted by Monckton is way higher than observed at present. However, if one simply overlays the NOAA data on the IPCC plot using identical scaling one ends up with the following:
The NOAA data corresponds very closely to the IPCC A2 scenario.
IPCC scenario atmospheric CO2 concentrations can be found here: