Porte ASO EU OONs soe Ue lari alel N 53 
... The U.S. timber supply STILL comes entirely from wild trees 
which cost us nothing—forests we inherited simply by sailing across 
the Atlantic. The theory of ‘sustained yield’ has yet to be put into 
practice. Presently we are mining cellulose patiently accumulated by 
nature over many centuries. The lode is nearly exhausted.” 
—Harvey Manning/Friends of Earth News 
velop various models of the future 
world system. Many of the global 
models which integrated the best 
available data for the five above 
factors are shown in the book. 
The most disturbing model is the 
standard run and assumes no major 
change in the physical, economic, 
or social relationships that have 
controlled the world system. Based 
on these present relationships, the 
model indicated that a rapidly de- 
clining resource base will soon 
drive down industrial output and 
food production and _ eventually 
population growth. The timetable 
for these changes to occur is es- 
timated to be between 10 years on 
the radical side and 70 years on the 
conservative side. 
Another model, which assumes a 
doubling of the presently known 
resource reserves, shows that world 
growth stops because of increasing 
pollution levels that overload the 
natural buffering capacity of the 
environment. Pollution causes in- 
creased death rates and decreased 
food production. Only a few more 
years of exponential growth are 
added to world growth by doubling 
the resource base. Many other mod- 
els using different combinations of 
data are also shown and explained. 
All arrive at essentially the same 
conclusion. 
The authors suggest that it is 
possible to alter these projected 
trends by setting up a long-term 
condition of ecological and eco- 
nomic stability. Computer models 
were also developed for conditions 
of global equilibrium and indicated 
that a stabilized population alone 
is not sufficient to prevent project- 
ed world changes. Both population 
and industrial growth (output) must 
be controlled to avert a collapse of 
the world system. When these two 
factors are controlled or limited, 
ecological, economic, and social sta- 
bility could be maintained far into 
the future. The authors do not es- 
timate how long. 
Most trained ecologists will hard- 
ly disagree with the results of the 
research presented in the book 
since it is a reiteration of what we 
have been saying for many years: 
our system can not continue at its 
present rate of exponential growth. 
There are already indications that 
resource base reservoirs are be- 
coming exhausted. The major prob- 
lem is the declining power base: 
brown-outs are common especially 
along the east coast; gasoline short- 
ages and rationing are forecast for 
the summer of 1973 and may be in 
effect by the time you read this 
review; and it is no longer possible 
to connect new houses to natural 
gas supplies. In fact, the natural 
gas shortage destroyed a sizeable 
portion of grain reserves this last 
year (no gas for grain elevators). 
The standard run model predicts 
that these situations will increase 
in frequency. 
There are some indications that 
population and industrial growth 
may be on the way down in the 
U.S. Liberalized laws on birth con- 
trol devices and legalized abortion 
have sharply slowed the population 
growth in the U.S. The control on 
industrial growth is also becoming 
effective, although the control is 
