Natural resources are materials and components that can be found in the environment, many of which are the source of man-made products used thoughout the world. Depletion of these natural resources can occur either through direct consumption (for example, eating an over-fished species of tuna or purchasing bookshelves made from virgin wood) or indirect consumption (for example, using plastic bags that are made with petroleum or leaving office lights on that use energy generated by burning coal).

Since the vast majority of natural resources are exhaustable, while our reliance on them is growing, taking steps to ensure the sustainability of these resources is paramount.