Figure 3: Annual temperature
trends for the periods 1901 to 1999, 1910 to 1945, 1946 to 1975 and 1976 to 1999
respectively. Trends are represented by the area of the circle with red representing
increases, blue representing decreases, and green little or no change. Trends
were calculated from annually averaged gridded anomalies with the requirement
that the calculation of annual anomalies include a minimum of 10 months of data.
For the period 1901 to 1999, trends were calculated only for those grid boxes
containing annual anomalies in at least 66 of the 100 years. The minimum number
of years required for the shorter time periods (1910 to 1945, 1946 to 1975, and
1976 to 1999) was 24, 20, and 16 years respectively. [Based on Figure
2.9]
