Editing The Limits to Growth (section)

==== Commodity reserve extrapolation ====
The chapter contains a large table that spans five pages in total, based on actual geological reserves data for a total of 19 non-renewable resources, and analyzes their reserves at 1972 modeling time of their exhaustion under three scenarios: static (constant growth), exponential, and exponential with reserves multiplied by 5 to account for possible discoveries. A short excerpt from the table is presented below:
:{| class="wikitable"
! colspan="2" | !! colspan="3" | Years
|-valign="top"
!align="left"|Resource!!Consumption, projected average annual growth rate!!Static index!!Exponential index!!5× reserves exponential index
|-
|width="100"|Chromium||width="100" align="right" |2.6%||width="100" align="right" |420||width="100" align="right"|95||width="100" align="right"|154
|-
|Gold||align="right"|4.1%||align="right"|11||align="right"|9||align="right"|29
|-
|Iron||align="right"|1.8%||align="right"|240||align="right"|93||align="right"|173
|-
|Lead||align="right"|2.0%||align="right"|26||align="right"|21||align="right"|64
|-
|Petroleum||align="right"|3.9%||align="right"|31||align="right"|20||align="right"|50
|}

The chapter also contains a detailed computer model of chromium availability with current (as of 1972) and double the known reserves as well as numerous statements on the current increasing price trends for discussed metals:

{{Blockquote|text=Given present resources consumption rates and the projected increase in the rates, the great majority of the currently important nonrenewable resources will be extremely costly 100 years from now. (...) The prices of those resources with the shortest static reserve indices have already begun to increase. The price of mercury, for example, has gone up 500 percent in the last 20 years; the price of lead has increased 300 percent in the last 30 years.|author=|title=|source=Chapter 2, page 66}}