The supply of these resources has the ability to impose strict limits on society, and humanity as a whole. Although it's not an immediate threat, our reserves are finite and depletion is inevitable. These resources did not appear overnight. A year's supply of oil for the United States alone takes Mother Nature one million years to make The time to take this into consideration is now. The way we harvest and conserve Earth's resources today has great bearing on the way we will live in the future.
Energy is required and relied upon for all of our daily activities.
Before continuing a discussion about specific resources, their availability, importance, and so forth it is important to define exactly what a resource is. Resource is a term which refers to the source in its entirety. This includes those portions which cannot now, nor ever, be extracted from the Earth for human use. On the other hand, the term reserve is used to define those portions of resources which are extractable with the technological and economical capabilites currently available. Thus, only certain portions of resources are actually reserves.