47
Figure 4.22: Adelaide airport 3 pm relative humidity: historical monthly averages and 2030 and 2070
projections under low and high emissions scenarios (50
th
percentile of GCM outputs).
Source: Derived from Bureau of Meteorology data, using climate change factors from
4.8.
Summary
x
Five scenarios were used to analyse future climate projections - 2030 high emissions, 2050 low
and high emissions, and 2070 low and high emissions.
x
The Study Area is projected to become warmer and drier over time. Drying of the climate is
projected to be accompanied by a slight change in the seasonality of rainfall. Climate models
suggest there will be less change during autumn than during spring, although changes in
atmospheric circulation with climate change suggest that autumn and winter rainfall may be most
affected.
x
Temperatures in the Study Area are projected to increase by between about 1.5° and 4°C by 2070,
with smaller changes projected for 2030 and 2050.
x
Heatwaves are projected to worsen, particularly by 2070. Their frequency, duration and intensity
are all projected to increase.
x
Rainfall is projected to decline by 2-5% in 2030 and by as much as 20-40% by 2070 across the
Adelaide region. Extreme rainfall events are projected to become more intense during spring and
summer.
x
Projected changes in wind speed and relative humidity are generally small. Annual average wind
speeds is not projected to be affected by climate change to 2070. Seasonal average wind speeds
38
43
48
53
58
63
68
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean 3pm relative humidity (%)
Historical
(1955-
2010)
2030 Low
2030 High
2070 Low
2070 High
