That is NOT a failed prediction. It is a failed "Lord" Monckton trick graph.
The actual CO2 ppm has been plotted correctly but he appears to have made up the IPCC forecasts. You should always be sceptical of people who do not supply data sources.
Here is a link to the graph he should have shown where the data actually comes from the TAR SRES emissions scenarios. These scenarios have a Low of 486ppm in 2100 to a high of 970 ppm in 2100. Nothing like a low of 730ppm as Monckton shows. http://www.ipcc-data.org/ddc_co2.html
Here is a link to the actual CO2 concentrations used by the IPCC. http://www.grida.no/publications/other/ipcc_tar/
Here is a link to where Monckton gets his data from to make up his graph to show how we are doing better than the IPCC predicts. You should note that he has taken the end points to use in plotting his graph. But the graph in the link below is to show the effects of including climate feedback on the carbon cycle. It should be used to look at the difference between the black and red lines. http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-4.html
