266 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 



the estimated total is represented by coal — a figure that will not be 

 greatly altered by any reasonable adjustments of the estimates of the 

 remaining fuels, but may be considerably altered if the minable 

 amount of coal is less than usually assumed. 



The amount of the initial coal already consumed is 1.35 percent; 

 that of oil and natural gas, inclusive of the Athabaska Tar Sands, 

 about 5 percent. The fraction of shale oil already produced is neg- 

 ligible. From these data the estimated initial supply of energy stored 

 in fossil fuels is of the order of 50 X 10^^ kilogram-calories, of which 

 O.TXlOi^, or 1.5 percent, has already been consumed. 



RATE OF CONSUMPTION CURVES FOR FOSSIL FUELS 



/ 



Time (Years) 



Figure 6. 



FUTURE OF FOSSIL ENERGY CONSUMPTION 



With this information we are prepared to consider what the future 

 of the consumption of fossil energy may be. In figure 6 is shown 

 the production of fossil energy up to the present, and two possible 

 projections into the future. One production curve rises to a high 

 peak and descends steeply; the second rises more slowly to a lower 

 maximum and descends gently. The area under each curve, however, 

 is approximately the same, namely 10 unit squares, each of which 

 represents 5 X 10^^ kilogram-calories. 



