Potentially recoverable resources: How recoverable?

There are a number of factors which are likely to limit the proportion of potentially recoverable resources that will actually be recovered. The most important of these concern the way minerals are distributed within the crust and trends in energy costs associated with mineral production. This article offers a pessimistic view of the prospects for mineral supplies early in the 21st century. The resource situation is even less hopeful when the possibility of extending the material living standards of the developed countries to everyone likely to be living on earth late next century is considered.