Scales of Climate in Designing with the Desert - Design with the Desert: Conservation and Sustainable Development - page 58

TABLE 3.1
Spatial Systems of Climate

Horizontal Scale
(Miles)

Vertical Scale
(Miles) System Time Scale

Global wind belts >1200 2-6 1-6 months

Regional macro 300-650 0.5-6 1-6 months

Local climate 0.5-6 1/60-1/6 1-24 h

Microclimate <1/6 <1/60 <24 h

Source: Barry, R.G., Trans. Inst. Brit. Geogr ., 49, 61, 1970.

space scale of any issue and the time scale required for consideration. The time scale in
this chapter is basically contemporary, that is to say twentieth century, and the near future.
Space limits the fascinating realm of long-term change of the climate system back before
the major impact of humans. 2

3.2 Global Scale
Figure 3.1 shows the global and central Arizona annual temperature anomalies (annual
differences from long-term mean) since 1950. The climate of the Southwest is one of past and
current variability, especially of precipitation, and an excellent review has been provided in
the literature of the southwestern United States. 3 In the realm of future planning, whether
these past trends persist at the same rate, abate, or amplify are important to several design

3

2

1

0

-1

Earth mean

-2

Central Arizona

-3

1950 1960 1970 1980 1990 2000

FIGURE 3.1
Earth mean and central Arizona temperature anomaly trends (base period 1950-2000; year minus the mean)
showing warming at two scales, especially since the mid-1970s. Central Arizona is a 328,000 mile 2 .