ENERGY FROM FOSSIL FUELS — HUBBERT 



269 



TIME PERSPECTIVE 



The present state of human affairs can best be appreciated in the 

 light of a time perspective, minus and plus, of some tens of thousands 

 of years from the present, as depicted in figure 8, On such a time scale 

 the phenomena we have discussed are represented by abrupt, nearly 

 vertical rises from zero or near zero to maximum values. The con- 

 sumption of energy from fossil fuels is thus seen to be but a "pip," 

 rising sharply from zero to a maximum, and almost as sharpl}'^ declin- 

 ing, and thus representing but a moment in the total of human history. 



WORLD POTENTIAL WATER POWER 



1950 2000 2050 



TIME (YeoM) 



Figure 7. 



The energy from water power and solar radiation also rises almost 

 vertically. It is physically capable of leveling off asymptotically to 

 a maximum value as shown in curve I and being held there more or 

 less indefinitely. However, it is also possible that it may decline to 

 some lower intermediate value as shown by curve II, or to zero, as in 

 curve III, depending upon the state of human culture during the next 

 few thousand years. 



Likewise the consumption of energy per capita, after having risen 

 very gradually from 2,000 to possibly 10,000 kilogram-calories per 

 day, is seen to increase suddenly to a maximum value of several times 

 the highest previous value. Again it is physically possible to maintain 

 a high value, as indicated by curve I, on a stable basis for an indefinite 

 period of time from current energy sources, particularly direct and 

 indirect solar radiation. It also is possible, however, that through 



