Exponential Growth: Plotting and Analogy

One reason that we have an energy problem is due to exponential growth which creates a strongly non-equilbrium use of our resources. (You wouldn't know we have an energy problem if you look at traffic at 5:00 p.m.)

Its not to great of simplification to state that the failure to understand the concept of exponential growth by planners and/or legislators, is the single biggest problem in all of Environmental Studies and/or Management.

The Two Principle Problems with Energy Management:

Exponential growth drives resource usage for a very simple reason:

Human population increases exponentially:

Accurate trend extrapolation is the most important part of future planning. However, failure to assume exponential growth will always lead to a disaster so always assume exponential growth when planning anything!

In this example, one can clearly see that no matter what the growth rate is, exponential growth starts out being in a period of slow growth and then quickly changes over to rapid growth with a characteristic doubling time of

Doubling Time (D.T.) = (70/n) years; n =% growth rate

Its important to recognize that even in the slow growth period, the use of the resource is exponential. If you fail to realize that, you will run out of the resource pretty fast:

Anytime growth depends upon a percentage on some amount that already exists we get Exponential Growth.

 

Exercise I. The Data Below was plotted in class using Excel Spreadsheet

Data Table

Number of Doubling Times

Amount of Stuff

0

1

1

2

2

4

3

8

4

16

5

32

6

64

7

128

8

252

9

512

10

1024

Graph of above Data:

Same Data Logarithmic Graph: Linear Relationship

Exercise II. Exponential Use: Analogy of the use of Natural Resources with Exponential Growth.

(Not totally accurate but any similarity between this analogy and reality is planned.)