11.9.3 Temperature and Precipitation Projections

Scenarios of temperature change and percentage pre-cipitation change between 1980 to 1999 and 2080 to 2099 are summarised in Table 11.1 (described in Section 11.1.3). A small value of T implies a large signal-to-noise ratio and it can be seen that, in general, the signal-to-noise ratio is greater for temperature than for precipitation change. The probability of extreme warm seasons is 100% in all cases for the small islands and the scenarios of warming are all very significant by the end of the century. Approximate results for the A2 and B1 scenarios and for other future times in this century can obtained by scaling the A1B values, as described in Section 11.1.3.

The temporal evolution of temperature as simulated by the MMD models for the 20th and 21st centuries is also shown in Figure 11.22 for oceanic regions including the Caribbean (CAR), Indian Ocean (IND), North Pacific Ocean (NPA) and South Pacific Ocean (SPA). In general, it can be seen, by comparison with Box 11.1, Figure 1, that the temperature increases for the small islands are less than for the continental regions. The almost linear nature of the evolution is also apparent in the figure. Temperature and precipitation projections for the small island regions are discussed below in the context of Table 11.1.

Figure 11.22. Temperature anomalies with respect to 1901 to 1950 for six oceanic regions for 1906 to 2005 (black line) and as simulated (red envelope) by MMD models incorporating known forcings; and as projected for 2001 to 2100 by MMD models for the A1B scenario (orange envelope). The bars at the end of the orange envelope represent the range of projected changes for 2091 to 2100 for the B1 scenario (blue), the A1B scenario (orange) and the A2 scenario (red). The black line is dashed where observations are present for less than 50% of the area in the decade concerned. More details on the construction of these figures are given in Box 11.1 and Section 11.1.2.