Here, you must specify the world as your region (-R0/360/-90/90). E. g., to obtain a hemisphere view that shows the Americas, try
pscoast -Rg -JA280/30/3.5i -B30g30/15g15 -Dc -A1000 -Gblack -P > GMT_lambert_az_hemi.ps
To geologists, the Lambert azimuthal equal-area projection (with origin at 0/0) is known as the equal-area (Schmidt) stereonet and used for plotting fold axes, fault planes, and the like. An equal-angle (Wulff) stereonet can be obtained by using the stereographic projection (discussed later). The stereonets produced by these two projections appear below.