The abundance of natural resources used to be generally assumed, but questions are beginning to be raised on a many fronts, including the availability of fuel and of nonfuel minerals, the potential productivity of agriculture, the supply of forest products and of water, and the increasing pressures of world population growth.
The current rate at which the human population is growing and using natural resources is fundamentally unsustainable and, without further change, a point will come when development would go into reverse. Many now estimate this to be at or before 2050.
Resources will continue to be limited. But the crucial factor is that the ratio of resources to results can be vastly improved through new knowledge, new technology, and hard-won experience.