Figure 2.25(ii): As in Figure
2.25(i) except annual trends for the three periods of changing rates of global
temperature (shown in Figure 2.9) and the full period, 1900 to 1999. During the
100-year periods, calculation of grid cell trends required at least 66% of the
years without missing data and at least three years of data within each decade
except the first and last. During the shorter periods, calculation of grid cell
trends required at least 75% of the years without missing data. Stations with
more than one sixth of their data missing during the normal period and grid cells
with more than one season or year without any measurable precipitation during
the normal period were excluded from consideration. Due to the nature of trend
estimation, it is not possible to cumulatively sum the trends for each of the
three periods to obtain an overall trend.
