Figure 4 is a line graph that plots past and projected annual mean GMST from the multi-model ensemble, relative to 1986–2005. Three lines are plotted: historical, RCP2.6 and RCP8.5. Historical data is plotted from 1950 to 2005, and RCP2.6 and RCP8.5 are plotted from 2005 to 2100.
The graph shows Temperature change (in °C) on the y or vertical axis against year on the x or horizontal axis. The historical temperature change rises from a little below 0 °C in 1950 to just above 0 °C in 2005.
RCP 2.6 shows the change rising gently to a peak around 2050 at close to 1 °C then it maintains steady value up to 2100.
RCP 8.5 shows a steady rise to an change of about 4 °C in 2100.
There are shaded regions around each line to show the 90% uncertainty range. This is typically around ± 0.2 °C or less for the historic data, around ± 0.5 °C for the RCP2.6 data by 2100, and around ±0.7 °C for the RCP8.5 data by 2100.